Browse Topic: Interiors, Cabins, and Cockpits

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Experimental Study on Partitioned Fruit and Vegetable Storage in Ships2026-99-15039/11/2026
After an investigation into a fruit and vegetable storage compartment on a ship, this paper proposes a method for creating different temperature zones within a single storage unit. To perform this approach, a top perforated plate air supply system should be implemented, and storage panels should act as partitions to make temperature control more accurate in different zones within the same compartment. This method ensures that fruits and vegetables can be stored for the best flavor at suitable temperatures, enabling fewer separate storage units on the ship. According to the experimental results, this solution can preserve various types of fruits and vegetables under different conditions during long trips, deal with the challenge of chilling or freezing injury due to mixed storage, and save the cold storage capacity on the ship. The proposed method has significant value in engineering applications.
Xie, Zhihao, Cui, Yonglong, Duan, Wenli, Li, Kun, Li, Qi, Wei, Shuaiju
Intelligent Mold Library System for Copper Tube Drawing Process2026-99-11089/11/2026
With the continuous and in-depth advancement of automotive lightweighting, the quality issues of automotive components have become increasingly prominent. Copper tubes, as an important component of automotive air conditioners, also need to ensure their quality level. In the production process of copper tubes, the multi- pass moving core head disc drawing process is one of the commonly used processing techniques. The relevant drawing dies determine the drawing effect and the quality of the finished copper tubes, so it is necessary to make a reasonable combination of drawing dies. At present, many copper tube processing enterprises overly rely on manual experience for mold matching work. Moreover, mold inventory information, usage records of matching molds, and mold size measurements are all completed by different operators. The operation procedures are not standardized, the standardization of mold matching operations is insufficient, there are too many uncertain factors, and the degree of human influence is too high. The intelligent mold library system for copper tube drawing process is designed to address the problems of weak stability, poor reproducibility, and insufficient precision in the existing manual mold matching. It facilitates accurate computation and control of process parameters. Compared with the estimation and rough adjustment based on manual experience, it can more accurately achieve the best parameter combination required by the process, thereby improving product quality and production efficiency. By integrating the mold matching methods of drawing pass process parameters such as the double decreasing method, the minimum pass method, the empirical pass method, the ZBL method, and the KD-KS coefficient method, and combining the inventory information in the system, it is ensured that the mold matching scheme generated by the algorithm is the best one, thereby improving the production level of the production process.
Yue, Fengli, Meng, Dezhi, Cui, Haitao, Zhang, Jiakun, Sun, Hongyun
Integration of Configuration Management into the RFLP Process in the Development of Civil Aircraft2026-99-14179/11/2026
In the forward development process of civil aircraft, traditional configuration management, which primarily focuses on the physical implementation end, often leads to inconsistencies between functions, requirements, design configurations, and physical realizations. This study optimized the principles of configuration item identification by refining the logic, timing, and sequence for identifying different types of configuration items. It proposed a product structure centered on the Logical Identification Number (LIN), which explicitly represents the mapping relationships from functional to physical elements. Additionally, the research established the logic for change propagation and validity calculation. Using an air-conditioning refrigeration system as a case study, the model was validated, demonstrating its advantages for improving the efficiency of change-impact analysis, enhancing compliance verification, and ensuring scenario reproducibility.
Xie, Xiang, Meng, Xu, Zhang, Xinyuan, Wu, Binbin
Data-Driven Design of Copper Tube Drawing Algorithm for Automotive Air Conditioning Systems2026-99-11109/11/2026
As a critical component in thermal management systems, copper tubes are widely used in automotive radiators, condensers, and other parts. In copper tube production, the drawing process is essential for achieving target dimensions and performance specifications. However, as the copper tube industry evolves, nowadays manual drawing process design and traditional drawing algorithms struggle to meet increasingly diverse finished product specifications and complex manufacturing requirements. To address this issue, this study developed an intelligent drawing process design algorithm suitable for automotive copper tube production. This algorithm builds upon existing drawing without plug algorithms, floating plug drawing algorithms, and manually compiled drawing process sheets. It first learns the fundamental principles of drawing without plug algorithms, then derives the relationship between wall thickness changes before and after drawing using mathematical formulas. Subsequently, by analyzing the enterprise’s existing 297 drawing process sheets, the design principles of the drawing without plug algorithm were extracted. This established the number and positioning of required drawing without plug processes within different drawing procedures as the design principles for drawing without plug. Then, using the ‘Double decrement method’ from the floating plug drawing algorithm as an example and integrating the design principles of drawing without plug processes, we developed an intelligent drawing process design algorithm suitable for automotive copper tube production. Furthermore, we selected a typical drawing process sheet for comparison. Through comparative analysis of key parameters such as processing rate and relative wall thickness reduction coefficient, we validated that this algorithm yields more rational results compared to traditional methods. Utilizing this algorithm not only significantly reduces the workload for drawing process designers but also produces more optimal drawing process design outcomes. Compared to other floating plug drawing algorithms, this algorithm also demonstrates greater universality.
Yue, Fengli, Zhang, Jiakun, Liu, Jinsong, Meng, Dezhi
Track De-icing and Road Maintenance Method Based on Induction Heating Technology2026-99-15369/11/2026
In order to solve the problems of long preheating time and high energy consumption caused by the traditional resistance heating track deicing technology and large power supply load, this paper presents a track deicing and road maintenance method based on electromagnetic induction heating. This paper studies the operational bottlenecks of the resistance heating system in a certain marshalling yard. It explains the eddy current heating from the principle of electromagnetic induction heating and designs an appropriate coil for turnouts and derives its power calculation formula. A mathematical model for the 'solid-liquid' phase transformation in the melting of snow is created and the melting parameter α = 0.623. In comparative experiments, compared to a 4kW electromagnetic induction heating device with no preheating time which melts snow up to 5cm in 40 minutes and consumes 40kW · h of energy in 1 hour, a 13kW resistance heating device needs 150 minutes to preheat, 180 minutes to melt, and consumes 130kW · h of energy. Use 70% less energy and help with track and road de-icing and upkeep with this technology.
Song, Zongying, Li, Zhongming, Wei, Dong, Yang, Jin, Wang, Xingzhong, Liu, Jingwei, Zhang, Xiaoyu
Investigation into the Crashworthiness of Freight Vehicles under Frontal Impact2026-99-12869/4/2026
This paper investigates the crashworthiness of freight vehicles under frontal impact based on the C-NCAP (China New Car Assessment Program) standard. Explicit dynamics and finite element methods were employed to conduct simulation analyses of the impact event, with the aim of offering references for improving vehicle crashworthiness. The findings indicate that the vehicle cabin remains largely intact, providing sufficient survival space for occupants. However, increased load amplifies the impact impulse and reduces crashworthiness. Additionally, the use of an enhanced anti-collision beam helps distribute impact forces and lowers the peak impact load.
Liu, Zihan, Jiang, Yi, Wang, Pu
Evaluation of the Isolation Efficiency of Quasi–Zero Stiffness Structure in Improving Seat Comfort of Different Commercial Vehicles02-20-01-00038/26/2026
Different commercial vehicles, such as the sunflower harvester, tracked vehicle, and vibratory roller, operate across off-road and on-road environments, often encountering rough and poorly maintained surface conditions. Thus, their comfort and working efficiency are very low. To solve this problem, a quasi–zero stiffness structure (QZSS) is investigated and added to traditional seat suspensions in the sunflower harvester, tracked vehicle, and vibratory roller to improve their comfort and working efficiency. From their established dynamic models, the isolating efficiencies and stabilities of QZSS are then analyzed in detail under different conditions of speed and seat mass. Reducing the root-mean-square values of the seat acceleration (aw) and displacement (zw) is used to evaluate the results. The research shows that the comfort of the sunflower harvester and vibratory roller is very poor compared with the tracked vehicle under the same simulation conditions. By adding QZSS to their seat suspension system, the values of {aw and zw} in the sunflower harvester, tracked vehicle, and vibratory roller are strongly reduced by {67.9% and 38.8%}, {54.7% and 23.9%}, and {65.4% and 34.3%} in comparison without QZSS. Therefore, the comfort of the three vehicle models is greatly improved in comparison without QZSS. Besides, QZSS improves the vibratory roller’s comfort better than the tracked vehicle, while QZSS improves the sunflower harvester’s comfort to be the best. These study results further strengthen the isolation efficiency of QZSS on different commercial vehicles. This contributes to providing more applicability of QZSS in real vehicle conditions.
Nguyen, Vanliem, Zhang, Li, Liu, Yaxi
Standard of Purity for Recycled R-134a (HFC-134a) and R-1234yf (HFO-1234yf) for Use in Mobile Air-Conditioning SystemsJ2099_202608 (Current)8/18/2026
This SAE Standard applies to: Recycled R-134a refrigerant, used in servicing of motor vehicle air-conditioning (A/C) systems Recycled R-1234yf refrigerant, used in servicing of motor vehicle air-conditioning (A/C) systems Hermetically sealed, refrigerated cargo systems are not covered by this document.
ICTMS Fluids Committee
Research on the Assembly Sequence Planning Algorithm under Cabin and System Constraints2026-99-03458/14/2026
Assembly sequence planning is a crucial part of process preparation in aircraft final assembly. A scientifically designed assembly sequence can significantly improve assembly efficiency and reduce costs in aircraft production. Efficient planning not only streamlines the workflow but also minimizes potential errors and rework, which are critical in high-stakes aviation manufacturing. This paper examines the constraint relationships in aircraft assembly from the perspectives of cabin constraints and system constraints, covering both spatial layout restrictions and functional logical dependencies to ensure the comprehensiveness of constraint analysis. It establishes a directed graph for the aircraft assembly outline and generates the corresponding adjacency matrix, which converts the complex constraint relationships into a structured mathematical expression for easier subsequent algorithmic processing. The Warshall algorithm and Johnson algorithm are used to check and extract contradictory constraints from the directed graph. The adjacency matrix is then employed to calculate the reachability matrix, which helps identify redundant constraints and reduces the computational effort in assembly sequence planning. Finally, the optimized constraint relationships are used to calculate the aircraft’s final assembly sequence, which generates a Gantt chart for assembly sequence planning, guiding the on-site assembly order and accelerating aircraft development efficiency. The integrated approach effectively addresses the key challenges in complex aircraft assembly sequence planning.
Guo, Jingjing, Cun, Wenyuan, Zhao, Jiong, Yu, Yang, Yang, Rui, Yu, Long
Gaining Approval for Seats with Integrated Electronics in Accordance with AC 21-49 Section 7.bARP6448C (Current)8/10/2026
This SAE Aerospace Recommended Practice (ARP) provides a framework for establishing methods and stakeholder responsibilities to ensure that seats with integrated electronic components (e.g., actuation system, reading light, inflatable restraint, in-flight entertainment equipment, etc.) meet the seat technical standard order (TSO) minimum performance standards (MPS). These agreements will allow seat suppliers to build and ship TSO-approved seats with integrated electronic components. The document presents the roles and accountabilities of the electronics manufacturer (EM), the seat supplier, and the TC/ATC/STC applicant/holder in the context of AC 21-49, Section 7.b (“Type Certification Using TSO-Approved Seat with Electronic Components Defined in TSO Design”). This document applies to all FAA seat TSOs C39( ), C127( ), etc. The document defines the roles and responsibilities of each party involved in the procurement of electronics, their integration on a TSO-approved seat, and the seat’s installation on an aircraft. Requirements for design and quality control and the methods for communicating design and change data between EMs and seat suppliers are defined such that standardization is possible across the industry to ensure continued airworthiness of TSO-approved seats with integrated electronic components. This document primarily focuses on correspondence between the seat supplier and the EM. Appendix A: Presents key characteristics of electronic components and guidance on how changes are classified per the requirements of Table 1 of AC 21-49. Appendix B: Provides an outline of a typical data approval process and the change management process between EMs and seat suppliers. Appendix C: While the responsibility rests solely with the seat supplier to ensure all TSO attributes identified in Table 1 of AC 21-49 are acceptable, Appendix C has been included to outline the process for delegating EMs authorization to assess the impact of changes on their equipment with respect to seat TSO attributes. This authorization will allow the classification of the change and the appropriate administration of the change by the EM via seat supplier delegation. Appendix D: Given the mix of business arrangements that can exist in the seat, in-flight, and aircraft procurement life cycle (buyer-furnished equipment, supplier-furnished equipment, customer-furnished equipment), there is discussion on the potential need for separate agreements between the EMs and seat suppliers to ensure binding flow down of design and quality control requirements. As such, a working together agreement (WTA) template is provided as Appendix D.
Aircraft Seat Committee
A Foundational CFD Validation for an Occupant-Centric HVAC Digital Twin: Paving the Way for Real-Time Control2026-99-10028/7/2026
The heating, ventilation, and air-conditioning (HVAC) systems are one of the main factors that contribute to the building’s energy usage. Achieving an effective balance between reducing energy use and maintaining acceptable thermal comfort is the key challenge in conventional HVAC systems. To overcome this challenge, integrating the occupant-centric controls coupled with digital twins into HVAC systems is another potential technique for this effective balance. For this purpose, computational fluid dynamics (CFD) offers the potential, in combination with other surrogate models for real- time applications to enhance the system's performance further. In general, the CFD is applied to investigate indoor airflow/temperature distributions. These are essential for occupant health, comfort, and energy optimisation for the HVAC design state. The objective of this study is to propose an initial step toward building an occupant-centric HVAC digital twin by validating a CFD model of an office against dense in-situ sensing data. The model has been used to resolve airflow and temperature stratification under conventional HVAC operations, using ANSYS Fluent. The boundary conditions have been derived from measured supply parameters, internal gains, and local weather conditions. The results from this study show that the air velocity and temperature at selected durations follow the same trend with low errors, compared to the sensing and measurement data. The model validation from this study establishes the basis for a weather- aware, occupant-feedback digital twin for larger floorplates and multi-zone systems. To achieve the target of the energy and comfort co-optimisation in Industry 4.0-ready buildings, the future work will focus on surrogate modelling to enable near-real-time inference for closed-loop occupant-centric controls, which will directly support dynamic set-point adjustments and multi-zone system ventilation.
Larpruenrudee, Puchanee, Hellany, Ali, Famakinwa, Tosin, Shrestha, Surendra, Attwater, Roger, Calheiros, Rodrigo Neves
EDITORIAL: Needed: Engineers “at the intersections”26TOFHP08_048/1/2026
It's near that time of year again when early-career and well-established engineers alike gather in Schaumburg, Illinois, for the annual SAE COMVEC conference (www.sae.org/events/comvec). From September 29 to October 1, attendees will listen to experts on a range of topics - from “Right Sizing Hybrid Powertrains” to “AI for Efficient Engineering Development” - walk the exhibit floor to witness the latest technologies and of course converse with one another over coffee or other beverages. KPIT Technologies is providing the executive leadership for this year's COMVEC and has a significant presence on the agenda, including the opening keynote by Omkar Panse, KPIT's chief technology officer (CTO). Panse and Satish Kumar, senior VP at KPIT, offered their insights on the engineering challenges and opportunities that next-generation commercial vehicles present in this issue's feature story on page 16.
Gehm, Ryan
Application of a Novel Noise-Reduction Material to Reduce Squeak Noise in Automotive Instrument Panels2026-01-50657/31/2026
In recent years, driven by increasing consumer demands for vehicle aesthetics and perceived quality, automotive instrument panels (IPs) have extensively adopted materials with poor friction compatibility, such as chrome-plated strips and synthetic leather. Concurrently, the engineering requirement for tighter matching gaps between components has significantly escalated the risk of friction noise. Traditional mitigation strategies—such as material substitution, increasing gap clearances, or applying physical isolation—are often difficult to implement due to design constraints, rendering the IP a critical high-risk zone for abnormal noise. This paper proposes a methodology to mitigate squeak noise between polycarbonate/acrylonitrile butadiene styrene (PC/ABS) and its mating counterparts by modifying the viscoelastic characteristics of the PC/ABS base material through the addition of a specialized polymer. Furthermore, a neural network model was established to objectively determine the noise compatibility of these materials. Evaluations of the material compatibility before and after modification demonstrate that adding a specific proportion of the special polymer to PC/ABS significantly improves its friction compatibility with materials such as polyvinyl chloride (PVC) skin. The efficacy of this solution was confirmed through application and verification in a mass-production vehicle.
Liu, Zubin, Cao, Chunyu, Hou, Hangsheng
Resilience Evaluation of HVAC Outdoor Units Against Typhoons Using Finite Element Method2026-99-01067/31/2026
In view of the practical problem that the air-conditioner outdoor units in the spacecraft test workshops of coastal launch sites are severely damaged under the influence of super typhoon, this paper employs the finite-element simulation method to establish a finite-element model of the outdoor units. The implicit Euler solution method is used to calculate the stress conditions of each component of the unit under the influence of typhoons with wind speeds of 50.9 m/s and 61.2 m/s respectively. By combining with the material yield strength, the weak links in the design are identified, and targeted improvement measures are proposed. The simulation results demonstrate good agreement with the actual impact of the typhoon, which can effectively guide the typhoon-resistance optimization design of subsequent air-conditioning units.
Gu, Yufei, Chen, Shaojiang, Shi, YunShan, Fu, Yuanming, Chen, Xi, Yang, Degang
Research on Failure Analysis of Aircraft Windshield Outer Layer Fracture Caused by Arc Fault2026-99-01287/31/2026
The malfunction of the aircraft windshield electric heating system, particularly arc discharge, poses a serious threat to flight safety by causing glass breakage. A systematic study was conducted on the causes and effects of arc faults on windshield structural integrity, employing macroscopic observation, microscopic analysis, and energy dispersive spectroscopy (EDS) following a windshield fracture incident. The results indicate that arc discharge typically occurs at the interface between the heating film busbar and adjacent structures. Localized high temperatures cause the outer glass to fracture, generating radial cracks. The ablation of the busbar silver coating and the carbonization of the PVB interlayer are direct evidence of arc action, whereas the heating wire remains a passive component affected by the high-temperature environment. The fault is primarily attributed to local disbonding at the busbar interface and moisture ingress. Based on the findings, recommendations are proposed for process optimization and inspection method improvement, providing a basis for the safe design and maintenance of windshield structures.
Chen, Li, Feng, Yanpeng, Ding, Keqin
Research on Thermal Design of a Forced Air-Cooled Display Control Console2026-99-08087/30/2026
In this paper, the simulation software was used to conduct a thermal analysis of the design scheme of a certain type of forced air-cooled display and control console, and the results were compared with the experimental results. The results show that in an environment of 50 °C, the maximum temperature of the chip on this strong display control console does not exceed 98 °C, meeting the usage requirements of the chip and the thermal reliability requirements of the display control console. The thermal design scheme of the display and control console proposed in this paper has the advantages of a simple structural form, good heat dissipation effect, low fan noise, and consideration of the heat dissipation of multiple heat sources. It can provide a good reference for the thermal design of similar display and control consoles.
Li, Yun
Experimental Study on the Temperature Impact of a Typical Cabin Fire on Adjacent Cabins2026-99-08667/30/2026
The cabins of ships are mainly made of steel. When a fire breaks out, the temperature inside the cabin rises rapidly, and an extensive body of heat spreads through the bulkheads to adjacent cabins. Understanding the variation law of the temperature field in adjacent compartments after a fire occurs in the compartments is of great significance for the research on the thermal safety of ship compartments. This paper designs an L-shaped cabin test system. We conduct fire tests of different scales and obtain the temperature distribution of adjacent compartments. The test results show that as the fire area in the pool keeps rising, the temperature in the adjacent compartments keeps rising. Due to the fact that an extensive body of high-temperature smoke produced by combustion is suspended at the ceiling of the compartment of fire, the temperature of the vertically adjacent compartments is higher than that of the horizontally adjacent compartments.
Hu, Wei-guo, Hu, Yang, Wei, Jin, Yuan, Ya-long
Dynamic and Static Optimization Design of Car-seat Structure2026-99-16147/24/2026
A car seat is one of the most critical components of passive safety. On the basis of the safety of car seats, this paper focuses on optimizing the design of the seat frame and achieving a lightweight design under various dynamic and static loading conditions. The optimization results are verified through physical experiments, which demonstrate the correctness and feasibility of the proposed design method. These experiments also provide research ideas for the optimization design of the seat structure and a certain reference value for the engineering application of the seat.
Shao, Youlin, Ni, Weiyu, Chen, Daojiong
Fatigue Life Analysis of Diesel Engine Filter Seat under Random Vibration Condition2026-99-16567/24/2026
The filter seat of diesel engine fuel filters is a key load-bearing component in the engine fuel system. Its structural integrity directly affects the reliability and safety of fuel delivery. In actual operation, the filter seat is subjected to random vibration loads generated by engine operation and vehicle dynamics, which may cause fatigue failure over time, even when static stresses are below the yield strength. This study employs finite element modeling (FEM) to investigate the structural strength and fatigue life of the diesel engine filter seat under random vibration conditions. The CAD model is simplified and meshed to reflect the main load paths, and boundary conditions, including bolt preload, gravity, and measured vibration PSD spectra are applied. Modal and harmonic response analyses are performed using Abaqus, and the Tovo-Benasciutti frequency-domain method is used in fe-safe to predict fatigue life. The results identify the most fatigue-sensitive areas and reveal that the minimum fatigue life is 10^3.067 cycles under realistic conditions, with the most critical regions located near the bolt connection. The simulation methodology and results provide a reliable basis for structural optimization and life prediction of similar components under random vibration environments.
Gu, Kexuan, Zhu, Yi, Xie, Liang, Wang, Wei
Study on Cleaning Requirements and Verification Methods for Oxygen Equipment of a Certain Type of Civil Aircraft2026-99-18037/17/2026
Pollution in the oxygen system of civil aircraft may lead to fire accidents, and maintaining the cleanliness of oxygen equipment is the most effective measure to reduce the risk of fire. This paper introduces the cleanliness requirements, cleaning methods, and procedures of oxygen equipment, and combines the cleanliness level requirements of oxygen equipment for a certain type of civil aircraft. By detecting the total weight of Non-Volatile Residue and the size and quantity of particles on the surface of the parts, it verifies whether the specific cleaning process can meet the cleanliness level required by the design. In addition, the possible sources of pollutants are analyzed based on the first unqualified verification results, and targeted improvement directions for the process are provided. After re-performing the cleanliness verification test, the results passed successfully, indicating that the process improvement is effective and has passed the airworthiness certification of the reviewer.
Huang, Jingqi
Aircraft Evacuation Simulation Study2026-99-18457/17/2026
This study analyzed the evacuation process of aircraft cabin personnel, with a focus on the impact of emergency exit configuration on evacuation efficiency. The research results indicated that the number and location of emergency exits are key factors determining evacuation time. In the case of only one exit, the evacuation time was significantly longer than that of multiple exit configurations. Utilizing three exits could reduce the evacuation time to 76 seconds. Additionally, the age and gender distribution of passengers, as well as priority rules, also had a significant impact on the evacuation process. The study further demonstrated that the activation of emergency exits and rear cabin doors could significantly enhance evacuation efficiency, while the opening of the front cabin door had a relatively smaller effect.
Wang, Kai, Wu, Bin, Li, Guolin, Yue, Chaoyu, Zeng, Tai, Su, Zhengliang
Calculation and Analysis of Civil Aircraft Depressurization2026-99-18347/17/2026
Analysis of cabin depressurization is key to ensuring civil aircraft airworthiness safety. In this study, we use a comprehensive approach to analyze depressurization scenes under regulations such as CCAR 25.841. For cases with and without cabin altitude warnings, we calculated critical leakage areas using an orifice flow model and iterative numerical methods. This combines inputs like emergency descent envelopes, air supply rates, and cabin parameters. In our analysis, we evaluate system failure impact and structural breaches on cabin pressure dynamics. For cases where the critical leakage area failed to meet the limits, we use an equivalent safety analysis based on the Depressurization Exposure Index (DEI). This combines pressure and exposure duration to measure physiological risks. We validated this approach through Simulink simulations and case studies, and found that it supports airworthiness verification, emergency descent optimization, and structural design improvements. This method provides a robust framework for enhancing civil aircraft depressurization safety.
Zheng, Bian
Lighting, Aircraft Interior, Installation ofAS18276B (Current)7/16/2026
This specification covers the installation of aircraft interior lighting for military aircraft.
A-20C Interior Lighting
Multi-Objective Optimization Research and Design of Seat Structure in Vehicle Collision2026-99-05187/10/2026
The vehicles often accompanied by a huge impact in the collision process, high-quality and high-strength car-seats can better protect the safety of passengers. However, in the call for vehicle energy saving and emission reduction, the lightweight design of car-seats is imminent. Therefore, it is necessary to achieve lightweight seat weight while ensuring vehicle safety. Based on the dynamic condition of vehicle collision, this paper takes the rear seat of a certain model as the research object, takes multiple responses of the seat skeleton system as the target, establishes a multi-objective optimization model of the seat skeleton, determines the optimization result with the greatest comprehensive satisfaction, verifies the optimization result of the seat skeleton. The correctness and feasibility of the design method are proved.
Shao, Youlin, Ni, Weiyu, Chen, Daojiong, Cheng, Zhiqing
Human-Machine Ergonomics Analysis of Civil Aircraft Electric Pilot Seats2026-99-05707/10/2026
This paper uses a structured evaluation framework to study the ergonomics of electric pilot seats in modern civil aircraft. We have established a multi-level indicator system to examine the adjustability, pressure distribution, dynamic response and, fatigue relief effect of the seat. All experimental data were obtained from a full-scale cockpit simulator environment, where a ground-based mock-up and motion-free simulated cockpit were used to replicate real operational posture, control-reach conditions, and long-duration mission loads. This framework combines experimental measurement and fuzzy evaluation techniques to quantify the quality of human-computer interaction. Test results show that compared with ordinary seats, the prototype seat has a wider adjustment range, a more uniform pressure distribution, and a smoother dynamic response. It is particularly worth mentioning that it can delay the emergence of fatigue during long-term operation, which proves the advantages of the electric adjustment mechanism. The simulated-cockpit test conditions ensure that these results are reproducible and representative of actual cockpit usage scenarios. This findings not only provide theoretical guidance and engineering basis for optimizing the cockpit seat system, but also provide methodological reference for applying fuzzy analysis in aerospace ergonomics research.
Tian, Yanan, Pi, Zhengyang
Research on Predicting Occupant Height Using CNN-Based Pressure and Posture in Zero-Gravity Seats2026-99-05217/10/2026
Zero-gravity seats alleviate prolonged sitting fatigue by optimizing human body pressure distribution, but the correlation mechanism between body size parameters and pressure distribution remains unclear. This study proposes a deep learning model based on multimodal data fusion, combining pressure matrices and postural angle data to construct a convolutional neural network (CNN) with a height prediction error ⩽3 cm. Experiments collected pressure and posture data from 100 participants with diverse anthropometric percentiles. Through the fusion of features and the optimization of the model, the study managed to quantify how height and weight impact pressure gradients. The results indicate that the model achieved a prediction R2 value of 0.73, which confirms that there is a strong correlation between pressure distribution and body size parameters. The findings offer theoretical and technical support for the adaptive adjustment systems within intelligent cabins.
Bi, Tengfei, Nie, Jiacheng, Du, Changjiang, Ji, Yuechen, Wang, Song, Sun, Jiawei
Improved Thermal Management for Operating a Battery Electric City Bus under Real Driving Conditions2026-01-07587/1/2026
The goal of reducing global CO2 emissions requires actions especially for the transportation sector. To achieve the goal, electric traction motors are frequently implemented in passenger vehicles, as well as in commercial vehicles like heavy-duty trucks or buses. Particularly electric city buses have the potential to reduce the local emissions in urban areas and provide local exhaust-emission-free mobility. While their number of registrations rises, research focusses on the improvement of the overall system in order to increase energy efficiency. High importance is gained by the thermal management of the whole system. This research investigates a simulative approach to improve the thermal management and therefore the energy efficiency of an electric city bus. The different thermal components of an electric city bus like drive system, battery system and heating, ventilation and air conditioning system (HVAC system) are modelled. Their thermal behavior has been validated in previous research. Based on the validated model, this study proposes an improved thermal management that, state-dependent, combines the thermal circuits of the single components to reduce the overall energy demand. Cooling or heating is provided by the HVAC system. Furthermore, the simulation utilizes real driving cycles of a city bus in the Hamburg area. Measurement data from an entire year are examined by a cluster analysis that results in typical application profiles for urban bus traffic. These profiles are used as basis for further research. An operating strategy for the thermal management of an electric city bus under real driving conditions is developed using the simulation model. Results are presented, which show that the overall energy demand decreases due to an improved, application profile-dependent thermal management system.
Schäfer, Henrik, Hellberg, Tobias, Meywerk, Martin
Passenger Oxygen MaskAS8025A (Current)6/29/2026
This standard covers oronasal type masks which use a continuous flow oxygen supply. Each such mask comprises a facepiece with valves as required, a mask suspension device, a reservoir, or rebreather bag (when used), a length of tubing for connection to the oxygen supply source, and a means for allowing the crew to determine if oxygen is being delivered to the mask. The assembly shall be capable of being stowed suitably to meet the requirements of its intended use.
A-10 Aircraft Oxygen Equipment Committee
Chemical Oxygen SystemsAIR825/4A (Current)6/29/2026
This SAE Aerospace Information Report (AIR) provides an orientation regarding the general technology of chemical oxygen generators to aircraft engineers for assistance in determining whether chemical oxygen generators are an appropriate oxygen supply source for hypoxia protection in a given application and as an aid in specifying such generators. Information regarding the details of design and manufacture of chemical oxygen generators is generally beyond the scope of this document.
A-10 Aircraft Oxygen Equipment Committee
Automosphere: Exploring Vehicle Heads-Up Display with Weather-Related Windshield Cues for Passive Fatigue Management12-09-03-00256/26/2026
Passive fatigue can cause accidents with automated and regular vehicles. A proof-of-concept prototype [made with light-emitting diode (LED) matrices and white LED (WLED)] and a preliminary comparative usability test (N = 7) are used to study whether the active manipulation of simulated weather cues can be a potential countermeasure to passive fatigue. Participants rated system suitability, system impression, and their fatigue level similarly when they viewed a weather windshield heads-up display (HUD) versus a speedometer windshield HUD [no significant differences found and relatively small 95% confidence interval (CI) ranges around 0]. Qualitative analysis of interviews found that participants saw the potential value of the weather display and that display placement, dynamic graphics, and user activation were commonly mentioned themes. These results suggest the concept is theoretically possible, though further work is needed to prove the concept in practice.
Ensafjoo, Mohsen, Li, Jamy
From Simulation to Shop Floor: Bridging the Sim‑to‑Real Gap for Humanoid RobotsTBMG-554356/26/2026
Humanoid robots are moving beyond hype-driven prototypes toward early commercial deployment, with automotive manufacturing emerging as the first scalable adoption market, according to IDTechX’s recent report Humanoid Robots 2026-2036: Technologies, Markets, and Opportunities.
BAND, MALE COUPLING, 6 INCH AIR DUCTAS7365/9A (Current)6/23/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Automotive Air-Conditioning Service Ports Task Force Field Survey ResultsJ3267_202606 (Current)6/23/2026
The automotive air-conditioning service ports task force conducted a field survey with MACS (Mobile Air Climate Systems Association) in June 2021. The scope of this survey was to determine the types of failures reported primarily at member service shops related to automotive air-conditioning service ports.
ICTMS Supplier Committee
The Influence of Interior Noise on Just-Noticeable Speed Differences in Conventional and Electric Vehicles2026-01-06716/20/2026
Electric vehicles (EVs) and internal-combustion-engine vehicles (ICEVs) differ fundamentally in their in-cabin acoustics, notably the attenuation or absence of engine-order content. Prior work reports associations between reduced engine sound, speed underestimation, and poorer speed maintenance; however, research on how EVs’ new sound affects speed perception and control is scarce, and most newer studies focus on comfort and subjective pleasantness rather than speed perception. Addressing this gap, the present study uses a two-interval, two-alternative forced-choice (2AFC) paradigm to directly measure just-noticeable differences (JNDs) in speed under ICEV, EV, and silent conditions. Thirty participants performed a 2AFC task in which, on each trial, they viewed two first-person highway clips (reference vs. comparison) and indicated which appeared faster. Results from ANOVA and post-hoc tests indicate that at the 40 km/h reference speed participants showed no clear differences across sound conditions, whereas at 100 km/h there were marked differences in JND: mean values were 1.93 km/h (ICEV), 3.48 km/h (EV), and 5.15 km/h (silence). A psychoacoustic parameter analysis suggests that this effect is not explained by speed-dependent changes in loudness or sharpness; we interpret that RPM-related, clearly audible frequency shifts in ICEV provide the primary contributory cue. For EV NVH or artificial sound design, enhancing speed-contingent, trackable spectral cues while respecting comfort may help maintain drivers’ ability to discriminate speed differences.
Li, Zhenxian, Parizet, Etienne, Colangeli, Claudio
Spatial Optimisation of Inner Dash Acoustic Performance Using Reciprocal Holography2026-01-07126/20/2026
As acoustic requirements for NVH trim components become increasingly constrained by mass, cost, and sustainability targets, traditional approaches to inner dash design based on spatially averaged Transmission Loss (TL) metrics are reaching their practical limits. In fully built vehicles, the acoustic performance of the inner dash is governed by its global insulation capability but also by strong spatial heterogeneity and its interaction with spatially distributed noise sources such as the power unit, gearbox, and tyre-road excitation. This paper presents a test-based methodology for the spatial optimisation of inner dash acoustic performance using reciprocal holography. By applying a calibrated sound power source within the vehicle cabin and measuring the reciprocal response in the engine bay and wheel-arch regions, a high-resolution spatial Transmission Loss “hologram” of the inner dash is obtained under in-situ conditions. The resulting spatial data enables the identification of localised acoustic weak points that are not observable using conventional testing methods. To bridge the gap between passive component characterisation and real-world vehicle operation, the spatial TL hologram is subsequently evaluated using representative operational source sound power data to prioritise acoustically relevant regions. This enables the transmitted acoustic energy to be evaluated under realistic driving conditions. The holographic data is then coupled with a parametric acoustic model of the inner dash system, allowing localised mass redistribution to be optimised using a genetic algorithm while respecting packaging and manufacturing constraints.
Harry, Evan, Eandi, Giacomo
An Experimental Setup for Vibroacoustic and Fluid-Born Noise Characterization of Electric Refrigerant Compressors Using R1234yf or R7442026-01-07246/20/2026
The increasing electrification of vehicles means that heating, ventilation and air conditioning systems have a broader range of tasks and a different priority assessment. In electric cars, air conditioning systems are not only responsible for cooling the passenger compartment, but also for controlling the battery temperature, particularly during rapid charging, which represents a high-load operating point. Furthermore, achieving high thermodynamic efficiency is desirable, as this directly impacts the range of electric cars. The elimination of the combustion engine as a major source of noise prioritizes the noise, vibration and harshness behavior of the refrigerant compressor for product selection. To investigate the vibration and acoustic behavior, as well as the fluid dynamic forces resulting from the cyclic compression principle of an electric refrigerant compressor, a test rig was developed that allows compressors to be operated and measured in isolation in an anechoic chamber under various defined operating conditions. This test rig has been expanded in two ways within the scope of this work. Firstly, the compressor can be either rigidly attached to a dead mass using a VDA mount or measured while suspended freely. Secondly, a new R744-compatible refrigeration circuit has been added to the test rig, enabling compressors operating with the environmentally friendly refrigerant CO₂, which has so far only been used by a few manufacturers in selected models, to be tested. Measurement results obtained using this test rig provide valuable insight into the vibration behavior and sound spectra of the refrigerant compressor's fluid, structural, and airborne noise when operating at different points.
Beer, Gabriel, Saur, Lukas, Schwarz, Manuel, Zemsch, Stefan, Becker, Stefan
Vibration Synthesis and Seat Dynamics Compensation for Single-Axis Seat Vibrations in Driving Simulators2026-01-06736/20/2026
Realistic seat vibration reproduction is essential for delivering authentic haptic cues and enhancing driver immersion in driving simulators. Unlike direct playback of road recordings, simulator applications require vibration synthesis that responds interactively to driver inputs and vehicle dynamics. Reproducing these vibrations at the seat is often complicated by actuator bandwidth limitations and the dynamic behaviour of the seat structure itself, which can alter the intended target response. This work presents vibration synthesis and seat dynamics compensation strategies implemented on a single-axis seat vibration reproduction system equipped with a vertical actuator. Frequency Response Functions (FRFs) were measured to characterise the system dynamics under single-axis excitation. Run-up and coast-down tests were conducted on the seat and compared to target responses measured on an actual vehicle under operational conditions. Several seat dynamics compensation strategies were evaluated, including inverse FRF filtering, energy-based matching, and manual frequency-domain equalisation. The results indicate that single-input single-output (SISO) compensation approaches can achieve reasonable performance under independent single-axis excitation when compared to alternative methods. The study presents a comparative evaluation of these methodologies and highlights their respective challenges and limitations.
Muthu Chaiphas, Joshua Daniel, Cuenca, Jacques, Bianciardi, Fabio, Colangeli, Claudio, Deckers, Elke, Denayer, Hervé, Janssens, Karl
Spatial Noise Acquisition at the Driver’s Position in an Electric Vehicle with Increased Accuracy2026-01-07236/20/2026
In vehicles with electrified powertrains, high-frequency tonal noise components have become increasingly prominent and can be perceived as particularly annoying by the driver. While recent advancements in international standardization — such as ECMA-74 [1] and ECMA-418 [2] — have led to powerful new algorithms for tonal noise visualization and analysis, including Tonality-Heatmaps, the measurement side still lacks sensor setups that adequately reflect the spatial sensitivity of noise, especially for tonal components. This challenge is amplified in enclosed vehicle cabins, where room modes create local minima and maxima that become increasingly dense at higher frequencies. As a result, even small head movements can lead to noticeable differences in perceived tonal noise. Current measurement approaches do not sufficiently account for this spatial variability. This contribution addresses the absence of tailored solutions for the driver’s position by introducing an improved microphone arrangement that significantly reduces the uncertainty of measured noise levels. The proposed setup considers spatial variability without compromising comfort or crash safety requirements. By enhancing the precision of tonal noise quantification, this approach provides noise-vibration-harshness (NVH) engineers with a valuable complement to modern software-based tonal analysis methods. The paper discusses the technical implementation constraints and demonstrates the comparability of the new measurement technique with conventional setups.
Schecker, Daniel, Rittenschober, Thomas
Vibro-Acoustic Simulation for Vehicle Audio Design2026-01-06706/20/2026
Acoustic user interfaces and audio experiences are among the leading comfort factors in new vehicle interior designs. OEMs are more and more focusing on loudspeaker design and positioning, to provide the most immersive experience to the customers. The industrial target is to be able to predict the performance of an audio system in early design phases. This paper presents an integrated vibro-acoustic methodology enabling early-stage prediction of loudspeaker performance in real vehicle conditions. The approach combines electromechanical characterization, a hybrid loudspeaker calibrated model valid across the audible range and coupled FEM/BEM/SEA simulations to capture the loudspeaker response in the vehicle’s cabin considering door-installation effects and cabin acoustics. The method is validated experimentally on a rear-door loudspeaker installed in a production vehicle, showing strong correlation with measured SPL. A final application case demonstrates its capability to assess the impact of alternative speaker mounting positions during the design phase.
Zerrad, Mehdi, Errico, Fabrizio, Mordillat, Philippe
Design Criteria and Certification for OEM Mobile Air Conditioning Evaporator and Service ReplacementsJ2842_202606 (Current)6/19/2026
The intent of this standard is to establish a framework to assure that all evaporators conforming to its requirements demonstrate an acceptable health and safety environment for vehicle occupants as determined from the completed risk assessment. R-744 and low pressure (i.e., non-transcritical refrigerants with a critical temperature between 85 and 120 °C) mobile air conditioning (MAC) refrigerant evaporators shall meet the testing and labeling requirements of this standard. SAE J639 contains a list of all refrigerants considered acceptable for use in mobile thermal systems for which this standard applies when the refrigerant is used in a direct expansion architecture. SAE J639 also requires an assessment to be performed to minimize reasonable risks in MAC systems. The evaporator (as designed and manufactured) shall be part of that risk assessment, and it is the responsibility of the vehicle manufacturer to ensure all relevant aspects of the evaporator are included. It is the responsibility of all vehicle or evaporator manufacturers to comply with the standards of this document at a minimum. (Substitution of specific test procedures by vehicle manufacturers that correlate well to field return data is acceptable.) As appropriate, this standard can be used as a guide to support risk assessments. With regard to certification, most vehicle manufacturers have established formal production part approval processes (PPAP) where compliance certification is established and formally documented. For an evaporator manufacturer of non-original equipment parts (or a vehicle manufacturer that does not have a formal part compliance certification process), then the certification described in this standard is the requirement to which those evaporators shall comply. In this case, the evaporator manufacturer or an independent institution shall complete the evaporator certification according to SAE J2911. An example of the latter would be the completion of witness testing by the evaporator manufacturer with the submission of certification documents by the witness organization. This standard originated for the introduction of R-1234yf. The content is based upon the associated 2011 Risk Assessment with input from five OEM evaporator manufacturers. R-744 was included as its requirements were understood in 2011. Refrigerant R-152a was excluded from this standard because a single secondary loop refrigerant system is required. This standard also does not apply to R-134a refrigerant evaporators because it is proven in use.
ICTMS Supplier Committee
Personal Protective Devices for Toxic and Irritating Atmospheres Air Transport Flight Deck (Sedentary) CrewmembersAS8031A (Current)6/18/2026
This SAE Aerospace Standard (AS) covers any protective system that serves the stated purpose.
A-10 Aircraft Oxygen Equipment Committee
Study of Hot Air Recirculation in Engine Compartment of a Newly Developed Sport Utility Vehicle03-19-03-00136/17/2026
During idling tests of a newly developed sport utility vehicle (SUV) under tropical high-temperature conditions, the condenser surface temperature exceeded the allowable range, degrading the air-conditioning system’s cooling performance. In this study, a three-dimensional computational fluid dynamics (CFD) model of the engine compartment flow field was established using STAR-CCM+. The results reveal that under idling conditions, the kinetic energy of hot air passing through the cooling module was insufficient to overcome the pressure difference between the front and rear sections, thus inducing hot air recirculation (HAR) and increasing the overall compartment temperature. To address the unfavorable flow field characteristics, four structural improvements were proposed and simulated for both flow and temperature fields. Through comparative analysis, the optimal scheme was determined: installing a flow guide baffle above the engine. Simulation results show that the airflow velocity above and below the engine increased by 54% and 71%, respectively, and HAR was effectively suppressed. The optimal scheme was further validated under real-vehicle idle conditions, and the temperature deviation between simulation and measurement was within 2%, confirming the reliability of the numerical model. In addition, the optimized scheme was verified under three typical harsh driving conditions, including hill climbing, high-speed climbing, and high-speed driving. Both simulation and test results indicate that the scheme significantly enhances airflow velocity in the engine compartment, with temperature errors maintained within 5%. The present study effectively mitigates the compartment temperature rise caused by HAR, and the proposed baffle scheme provides a feasible solution for the thermal management design of new SUVs under both idle and severe driving conditions.
Shi, Huojie, Rao, R.H., Chen, J., Zheng, Z.L.
Oxygen Cylinder Quality, Serviceability, Maintenance Transfilling, and MarkingAIR1059G (Current)6/15/2026
This document provides guidance concerning the maintenance and serviceability of oxygen cylinders beginning with the quality of oxygen that is required, supplemental oxygen information, handling and cleaning procedures, transfilling, and marking of serviced oxygen assemblies. This document attempts to outline in a logical sequence oxygen quality, serviceability, and maintenance of oxygen cylinders. Content of this document can also be used for refilling oxygen cylinders while installed on aircraft, directly or through an intermediate charging port.
A-10 Aircraft Oxygen Equipment Committee
Ergonomic Assessment of Glove-Box Design in Passenger Vehicles for the Indian Scenario15-19-02-00096/10/2026
Passenger vehicles experience severe packaging constraints around the instrument panel, rendering glove-box operation a critical yet ergonomically underexplored interaction. Although glove-box interaction occurs frequently during routine vehicle use, its potential implications for ergonomic risk remain largely unexamined in existing automotive research. To isolate the influence of driver-side packaging constraints from component-level design effects, this study adopts a comparative evaluation of driver and co-driver glove-box interaction as a built-in control condition. This study introduces a discomfort-based evaluation framework that integrates Digital Human Modeling with India-specific anthropometric datasets. A composite loss-function scoring model is developed to quantify functional usability differences across four glove-box configurations, defined by variations in latch placement (center or side) and storage-bin mechanisms (fixed or rotating). Indians are utilized to assess reachability and visibility during glove-box interaction. Ergonomic performance is analyzed through reach and visibility metrics for both latch actuation and storage-access tasks. For the co-driver, all configurations exhibit 0% loss, confirming that usability remains unaffected. In contrast, the driver assessment reveals pronounced limitations. Center-mounted latches prove inaccessible from a neutral seated posture, reflecting an approximate loss function of 55%. Among the side-latch alternatives, the rotating-bin configuration achieves the lowest discomfort score (41%), supported by more favorable access posture and smoother hand-entry alignment. The findings specify that ergonomic limitations stem primarily from driver-side packaging constraints rather than inherent flaws in the glove box unit. Based on the reach and visibility loss values obtained through the developed framework, the Side-Latch + Rotating-Bin configuration emerges as the most suitable design option for passenger-vehicle layout. The proposed methodology offers a practical decision-support tool for early stage ergonomic evaluation of glove-box configurations in passenger vehicles.
Jujjavarapu, Sreeram, Kota, Srinivas, Kotkunde, Nitin, Jasti, Naga Vamsi Krishna
Lunar Lander Landing Dynamic Model and App Development in Simscape®2026-01-60026/10/2026
With the recent renewed interest in manned lunar exploration, it is critical to revisit the Apollo Moon landings with new analysis tools. Modeling the Moon landings of the past can help guide the development of new landing vehicles for the present and the future. One of the critical subsystems to model is the vehicle’s landing gear. During a landing event, structural loading, energy absorption, and toppling stability are important factors that drive the design of landing gear subsystems. These aspects can be studied using models and simulations in addition to physical testing. This study explores one recent modeling tool for modeling the landing gear and uses the Apollo 11 Moon landing as a use case. A generic model was built using MATLAB®, Simulink®, and Simscape® Multibody to model the dynamics of a landing event. The landing gear structure comprising the primary strut, secondary struts, footpads, and joints was modeled in Simscape® Multibody. Various energy absorption mechanisms in the struts were modeled based on the relative motions of the inner and outer cylinders of the leg. Touchdown contact forces, when the footpads strike the lunar surface, were modeled considering the soil mechanical properties. Slosh dynamics were modeled using a mechanical pendulum module, and tip-over controllers were developed using Simulink®. However, neither was applied in the presented analysis relating to the Apollo lunar module. After developing the generic landing dynamic model, the Apollo 11 landing was simulated for validation purposes with results closely matching the historical measured data. A MATLAB® Graphical User Interface application (app) also was developed based on this model for usability and better accessibility of the landing simulation by non-experts on landing dynamics. It offered the opportunity for landing stability study with and without control, i.e., the max slope a lander can land without tipping over in 3D realistic landing situations.
Arndt, Grant, Wu, Wei, Butzman, Noah
Analysis of a Sorption Energy Storage System for Cabin Air Heating and Dehumidification in Electric Vehicles2026-37-00346/9/2026
This work investigates the integration of a Sorption Thermal Energy Storage (TES) into the Heating, Ventilation and Air Conditioning (HVAC) system of electric vehicles. The proposed device reduces the energy demand for cabin heating under winter conditions, leading to a driving range increase. The TES dehumidifies the cabin air through a desiccant bed (zeolite 4A), preventing window fogging, enabling higher air recirculation rates, and consequently reducing the required heating power. An experimentally validated numerical model was used to analyze the adsorption and regeneration processes and to identify suitable operating conditions. Regeneration was found to be effective at moderate temperatures (from 120°C), with a counter-current airflow configuration providing faster and more efficient desorption compared to parallel-flow one. A simplified model integrating TES, HVAC unit and cabin was developed and used to compare different configurations. Heating energy consumption with and without TES under different ambient conditions, passenger loads, airflow rates, and regeneration states was evaluated. Heating energy savings ranged from 19% to 71%, increasing with higher external humidity. Considering the desiccant bed volume, equal to 1.65 L, electric energy savings up to 1.7 kWh L-1 for heat pump systems and 3.3 kWh L-1 for electric heaters were estimated, corresponding to a potential driving range increase of 13.4 km L-1 and 33.5 km L-1, respectively. Preliminary TES tests on a mock-up vehicle confirmed the effective dehumidification capacity of the proposed technology.
Verlingieri, Rebecca, Calabrese, Luigi, Freni, Angelo, Marocco, Luca, Scudeler, Gabriele, De Antonellis, Stefano
Requirements Extract for AS861C Minimum General Standards for Oxygen Systems SA-DIG-000016/9/2026
This digital standard is a requirements extract of AS861C Minimum General Standards for Oxygen Systems. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
CFD Based Performance Prediction of Centrifugal Compressor2026-26-07266/1/2026
In modern engineering, compressors play a vital role across numerous industries by enabling the delivery of fluids at elevated pressures for a variety of applications, including HVAC systems, aircraft engines, and process industries. The performance of centrifugal compressors is characterized by parameters such as flowrate, efficiency, and pressure rise. Traditional methods of evaluating compressor performance, such as physical testing, are often time-consuming and costly, making them less practical for iterative design or optimization. Advancements in Computational Fluid Dynamics (CFD) have provided a faster and more cost-effective means of assessing compressor behavior. This study presents a comprehensive CFD-based analysis of a two-stage centrifugal compressor utilized in HVAC applications aimed at predicting its performance, that is, flow factor vs head factor and flow factor vs efficiency for given rotational speeds and inlet guide vane (IGV) angle positions. Focus is on predicting surge flow points, choke flow points, mapping the compressor performance curve and mapping surge line for IGV partial opening cases at various rotational speeds of the impeller. Simulations were conducted using the ANSYS CFX software. The results illustrate the effectiveness of CFD in accurately predicting critical performance metrics and operational limits for centrifugal compressors. Additionally, the study can potentially explore the impact of different geometric modifications on compressor stability and surge margin, providing valuable insights for future design improvements.
Turaga, Vijay Kumar, Aadi Gopalakrishna, Pradeep, Gugulothu, Sampath
Evaluation of Thermal Behaviour of Ramie Fiber/Delrin Composites for Aircraft Cabin Components2026-26-07546/1/2026
This research investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5-20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via the injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermal characteristics of the sustainable composites that were systematically evaluated as per the ASTM standards. The addition of RF drastically altered the Delrin matrix's performance. Among the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values, which provide greater dimensional stability at high temperatures; lower CLTE, resulting in less thermal expansion; comparatively better thermal conductivity; and improved heat dissipation. Eventually, there was a moderate drop in the MFI, indicating more rigid polymer chains that restrict the flowability of the composite, thereby increasing its heat-withstanding capabilities. DSC analysis revealed a slight upward shift in Tg and increased crystallinity, suggesting restricted polymer chain mobility and enhanced load transfer at 20 wt.% RF loadings, agglomeration effects, and weaker interfacial bonding with the matrix led to deterioration in properties. Aircraft cabin components like interior panels, ducting supports, and lightweight non-structural fittings requires dimensional stability, thermal resistance, and mechanical reliability under fluctuating flight conditions.
S, Thirumalvalavan, Senthilkumar, N., Selvarasu, S
Aircraft Cabin Diagnosis – Inspection of the Aircraft Cabins and Seats Using AI2026-26-07896/1/2026
Aircraft interior defects, including seat structural damage, cushion degradation, liquid contamination, and foreign object presence, contribute to increased maintenance burden, extended ground time, and operational inefficiencies. Current inspection practices rely predominantly on manual visual checks, which are time-intensive and limited in detecting concealed anomalies. This paper presents a non-contact, AI-enabled inspection framework integrating millimeter-wave (mmWave) radar sensing with high-definition optical imaging for automated aircraft seat condition assessment. The proposed system captures interior scans when the aircraft is unoccupied and compares them against a digitally established baseline reference obtained under certified, defect-free conditions. Data fusion and machine learning algorithms analyze deviations to identify surface and subsurface defects at seat-level resolution and generate zone-based maintenance maps. The primary technical contribution lies in combining subsurface-capable mmWave sensing with AI-driven deviation analytics to enable detection of concealed cushion defects and foreign objects, including service tools, which are not reliably identified through conventional visual inspection alone. The system outputs structured maintenance reports identifying seat location, defect classification, and severity prioritization, thereby supporting targeted corrective action and reducing troubleshooting time. In addition to in-service aircraft applications, the framework is extendable to seat production and final assembly inspection environments. Establishing a digital baseline during manufacturing enables inline quality validation, structural compliance verification, and traceable lifecycle data creation. This unified digital inspection approach supports predictive maintenance modeling, reduces rework and downstream maintenance events, and enhances overall aircraft interior safety and reliability assurance.
Nagoal, Chandrasekhar Reddy, Prathipati, Krishna Chaitanya, Kandukuri, Ravindra
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