Browse Topic: Pipes and ducts

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Study on Low-Velocity Impact Damage of Glass Fiber Reinforced Composite Pipeline2026-99-14169/11/2026
Through low-velocity impact testing, the effects of punch shape (conical, hemispherical, and cylindrical) and impact energy (5, 10, and 15 J) on damage characteristics in glass fiber composite pipes were investigated. Ultrasonic A-scan inspection was employed to detect internal delamination damage at the impact points within the composite pipes. Test results indicate that the contact area between the punch and the pipe is a key factor influencing the severity of pipe damage. A smaller contact area results in a higher energy absorption rate, greater punch displacement, larger area under the load-displacement curve, and longer contact time, leading to more severe damage characteristics. When the conical punch delivered 15 J of impact energy, the energy absorption rate of the glass fiber composite pipe reached 91.6%, exhibiting multiple damage characteristics, including pitting, penetration, and cross-shaped cracks. As impact energy increases, the area of internal delamination damage caused by the three punch shapes exhibits near-linear growth. The conical punch induces severe damage characteristics in the thickness direction but results in the smallest delamination area. Blunt-shaped punches (hemispherical and cylindrical) disperse impact energy over a wider region, leading to increased delamination damage area.
Wang, Xuan, Cao, Yanzhen
Experimental Analysis of Tube Temperature and Heat Transfer Performance of L-Shaped Gravity Heat Pipes2026-99-15119/11/2026
Gravity heat pipes achieve efficient energy transfer through the evaporation and condensation of their internal working fluid, which steadily conducts underground heat to the surface and thereby provides a continuous and stable heat source for road pavements in winter. Considering the snow and ice melting demand of road surfaces in winter, this paper establishes an indoor environmental simulation experimental platform to systematically investigate the influence laws of different working fluids on the start-up temperature, start-up pressure, heat transfer power, and other key performance indicators of L-shaped gravity heat pipes. Through experimental research and analysis, it is revealed that heat pipes with R-134a and R245fa working fluids can operate stably at a shallow geothermal temperature of about 25 °C, while the acetone working fluid heat pipe operates unstably under this condition. The heat pipe filled with R-134a working fluid achieves the maximum heat transfer power under shallow geothermal conditions, followed by the heat pipe filled with R245fa. Although the heat transfer power of the acetone-filled heat pipe is generally relatively low, its heat transfer power increases most significantly with the rise of the evaporation section temperature. Under low-temperature conditions, the thermal conductivity of the evaporation section increases with the rise in the heating temperature of the evaporation section, while that of the condensation section decreases with the increase in the heating temperature of the evaporation section. Through experimental research and comparative analysis, this paper deeply explores the application potential of gravity heat pipe technology in green highway construction, and evaluates the feasibility and economic benefits of its engineering implementation, which provides a scientific basis and engineering guidance for the selection of green energy in future infrastructure construction.
Wang, Zhen-kun, Yuan, Zhi-ming, Wang, Kang, Zhang, Wen-jun, Wu, Xiang-song, Liu, Guang-bo
Strain Analysis of Buried Pipelines in Trench Models Crossing Strike-Slip Faults2026-99-12809/4/2026
Long-distance buried pipelines are the core type in pipeline transportation; the technical indexes and requirements for protection are stricter. In the previous coupling model of pipe and soil, the in-situ soil and backfill soil are treated as a unified continuous medium, and the actual geometric shape and boundary effect of the pipe trench are ignored through simplification of the calculation model. In this study, a new coupling model of in-situ soil, backfill soil, and pipeline is proposed to analyze the actual strain state of buried pipeline with different backfill soil and in-situ soil materials. A model was established based on the ANSYS software to simulate and investigate the mechanical behavior of strike-slip fault-crossing buried pipelines under real trench conditions. By varying multiple parameters, this study analyzes the effects of different operating conditions on the strain distribution and magnitude of buried pipelines. The findings of this study can serve as a reference for the design, construction, and protection of buried pipelines traversing active faults.
Li, Yuxiang, Wang, Guang, Zhang, Chengbin, Wang, Ke, Bi, Haisheng
Experimental Study on Heat Transfer Performance of Gravity Heat Pipes in Green Highway Construction2026-99-12399/4/2026
Gravity heat pipe technology offers an innovative solution for utilizing shallow geothermal energy to melt pavement snow and ice in winter, aligning with the requirements of green highway construction. By leveraging the evaporation and condensation of internal working fluids, these heat pipes efficiently transfer underground thermal energy to the ground surface, delivering a continuous and stable heat supply for road pavements in cold weather. To explore the factors affecting heat transfer efficiency, this study built an indoor environmental simulation platform and systematically examined the impacts of heat pipe shape, working fluid type (R-134a, R245fa), heating temperature (15°C–25°C), and working fluid filling rate (15%–30%). A winter pavement snow- melting simulation experiment was conducted to quantify key indicators such as pipe wall temperature and heat transfer power under medium-low temperature conditions. Experimental results show that R-134a heat pipes outperform R245fa counterparts in heat transfer power under simulated shallow geothermal snow-melting conditions. Low filling volumes tend to induce temperature gradients in the condensation section of L-shaped heat pipes, reducing overall efficiency. Straight heat pipes work best at a 15% filling rate, while L-shaped models achieve optimal performance at 25%. Comparative experimental analysis yielded parameter-effect diagrams for heat transfer power and thermal conductivity, which clarify the variation rules of heat pipe performance and provide engineering guidance for gravity heat pipe applications in green highway construction.
Wang, Zhen-kun, Yuan, Zhi-ming, Wang, Kang, Zhang, Wen-jun, Wu, Xiang-song, Liu, Guang-bo
Numerical Simulation Study on Fire Prevention in Aero-Engine Fuel Tube2026-99-03038/14/2026
Transient gas-liquid two-phase flow in aero-engine fuel pipelines was examined using numerical simulations, focusing on the influence of flow rate on phase change behavior. Under low-flow conditions, phase change occurred repeatedly near the pipe wall, where vapor layers formed and collapsed in an intermittent manner. These processes introduced noticeable unsteadiness in the local mass flow and pressure fields. When the flow rate was increased, vapor generation was largely confined to a narrow region adjacent to the wall, and the overall flow exhibited a more stable character. The results suggest that flow-rate-dependent phase change plays an important role in determining the stability of fuel transport and should be considered in the fire safety assessment of aircraft fuel systems.
Wu, Bin, Xin, Bo, Zeng, Tai, Su, Zhengliang
Research on Flexible Positioning Technology for Airplane Pipe2026-99-03088/14/2026
Airplane pipe assembly is an important part of the aircraft manufacturing process. There are some limitations, such as poor adaptability and a long manufacturing cycle, in conventional clamps used for clamping pipes. To avoid these limitations, this paper developed a pipe clamping system with the capability of adapting pipes with different shapes and diameters. The least squares method was used to build a coordinate system for the pipe and pipe clamp system. The kinematical model of the pipe clamp system was analyzed. A method of finding the inverse solution of mechanical kinematical parameters was proposed, and was utilized to drive a mechanism performing a positioning function. The experiment, detailed in this paper, authenticated that the positioning precision of the pipe clamp system satisfies the requirements of airplane manufacture.
Xu, Jun, Zhao, Xi, Wang, Wei
Time-of-Flight Estimation Using the Discrete Logarithmic Frequency Method2026-01-50458/6/2026
Conventional measurement instruments such as scales, thermocouples, and laser-based technologies present challenges when used on lengthy and winding underground pipelines. These methods are often not feasible because of physical constraints, the challenge of light traveling in curves, and the need for large, energy-intensive sensors. Ultrasonic and microwave techniques both face challenges in making long-distance measurements because of rapid signal weakening and high energy requirements, which make them impractical for small pipes. This study introduces an original technique for Time-of-Flight (ToF) estimation using the Discrete Logarithmic Frequency (DLF) method to address these limitations. By analyzing the time–frequency correlations of signals transmitted through channels, the proposed technique enhances the precision and dependability of ToF measurements. By employing the DLF method, we are able to effectively gather and assess the signal’s performance as conduit lengths vary.
Chinni, Venkata Sai Sandeep, Balasubramanian, Prabakaran, Mamat, Rizalman, Yasin, Mohd
Analysis of Leakage Causes of 6ADG011VR Branch Pipe in a Power Plant2026-99-02317/31/2026
The socket-welded branch pipes of a power plant leaked and failed in the ADG System. To find the cause of the failure, this paper analyzed the failure reasons of the socket-welded branch pipes through macroscopic inspection, chemical composition analysis, mechanical performance test, metallographic inspection, and fracture microscopic analysis. The results show that the failure mode leading to leakage in socket-welded pipelines is fatigue cracking, which initiated at the weld toe on the outer wall and propagated inward. The vibration generated by the system environment is the main cause of fatigue cracking of socket-welded branch pipes.
Zhu, Jinhui
Temperature Distribution and Effects of Heat-Affected Zone on the Mechanical Microstructure and Properties of Steel Pipes during Cutting2026-99-01257/31/2026
This paper examines the temperature distribution during pipe cutting and the impact of the heat-affected zone on the mechanical microstructure and properties of steel pipes. Utilizing testing equipment such as K-type thermocouples, a MESTL-WELD thermocouple spot welding machine, and a DC5516H 16-channel temperature data logger, temperature tests were conducted on Φ 1016 × 17.5 mm X70M spiral seam submerged arc welded steel pipes and Φ 1016 × 21 mm X70M straight-seam submerged arc welded steel pipes. The results indicate that the maximum test temperatures during cutting were 953.8 °C and 1216.6 °C, respectively, with the duration of temperatures exceeding 400 °C at each test point not exceeding 30 seconds. By fitting the relationship curve between the peak temperatures of each test point and the cutting distance using the ExpDec3 model, it was found that the cutting distance corresponding to a temperature of 580 °C was 12 mm. Furthermore, mechanical microstructure and property tests were performed on the pipe body at different positions of the HAZ. Except for an anomaly in the yield strength of the rod-shaped tensile specimens of the Φ 1016 × 21 mm X70M welded pipe body, no other abnormalities were detected. Macroscopic metallographic examination revealed that the axial length of the HAZ at the end of the cut pipe did not exceed 7 mm. Microhardness testing showed significant fluctuations in the microhardness of the pipe body at the end of the cut pipe, while the microhardness of the pipe body beyond 10 mm from the end gradually returned to normal.
Xu, Yan, Bai, Qiang, Feng, Zhenjun, Chang, Yonggang, Li, Liang, Peng, Shibi
The Protective Mechanism of Polyurea/Aramid Fiber Reinforced Steel Pipes against Implosion-Induced Multi-Physical Field Loads2026-99-01357/31/2026
This paper studies the protective performance of polyurea-coated steel pipes and aramid fiber-wound steel pipes under the multi-physical field load of internal explosion by combining experiments with numerical simulation. The experimental results show that applying aramid fiber winding has a limited effect on improving the anti-explosion performance of steel pipes, while polyurea-coated steel pipes exhibit better anti-explosion performance under the coupled load of shock waves and fragments. Simulation analysis reveals the protective mechanism of composite structures in terms of energy absorption and stress distribution, providing a theoretical basis for the optimal design of blast-resistant vessels.
Tian, Xiangpeng, Wang, Tao, Bian, Xiaobing, Huang, Guangyan
Hybrid Particle Swarm Optimization and Machine Learning Framework for Enhanced Prediction of Ground Settlement during Rectangular Pipe Jacking2026-99-16477/24/2026
Accurate prediction of ground settlement induced by rectangular pipe jacking, a prevalent trenchless technology in urban infrastructure development, remains a significant challenge. This study addresses this by developing and evaluating a robust machine learning (ML) framework. Leveraging 104 sets of field monitoring data from the Liuye Avenue West Extension rectangular pipe jacking project in Hunan, China, key construction parameters including jacking force, advance rate, and grouting pressure were utilized as inputs to predict ground settlement. A Particle Swarm Optimization (PSO) algorithm was integrated for automated hyperparameter tuning of six distinct ML models: standalone Least Squares Support Vector Machine (LSSVM), Backpropagation Neural Network (BPNN), Random Forest (RF), and their respective PSO-optimized counterparts. Comprehensive performance evaluation using Mean Squared Error (MSE), Mean Absolute Error (MAE), and Coefficient of Determination (R^2) revealed that the PSO-LSSVM hybrid model achieved superior predictive accuracy and generalization capability. Specifically, on the test dataset, the PSO-LSSVM model yielded an MSE of 0.367, MAE of 0.424, and an R^2 of 0.941. These findings demonstrate that the proposed PSO-enhanced LSSVM model significantly outperforms baseline models, offering a highly effective and reliable tool for predicting ground deformation in similar complex pipe jacking projects.
Hu, Shiwei, Hu, Rong, Zhang, Hong, Chen, Yi, Hu, Da
Advanced Predictive Modeling of Pipeline Settlement in Rectangular Pipe Jacking Tunneling using Hybrid Deep Learning Techniques: A PSO-LSTM-Self Attention Approach2026-99-16487/24/2026
Nowadays, as computer technology makes quick progress, innovative algorithms like deep learning are getting used more and more in underground engineering and lots of other fields. When working on rectangular pipe jacking tunnel projects, accurately predicting the magnitude of pipeline settlement is really key to keeping the work moving smoothly. But traditional ground settlement prediction methods mainly rely on empirical formulas and numerical simulation software. When applied to tunnels with complex geometries, though, these methods usually don’t work as well as needed. To fix this problem, our study came up with a new model called PSO-LSTM-Self-Attention Mechanism (shortened to PSO-LSTM-SAM), specifically designed to predict pipeline settlement caused by rectangular pipe jacking work. This model takes the data collected from construction monitoring and uses that as the input for time series modeling work. That allows for in-depth analysis of real-time settlement data, and as a result, it can make more precise predictions of long-term pipeline settlement. To verify the effectiveness of the PSO-LSTM-SAM algorithm, the researchers compared its prediction results with those from a conventional LSTM network, an LSTM-SAM network, and a PSO-SVR network. They also checked the model’s performance by looking at pipeline settlement predictions from different monitoring points, using data from the Changsha Railway Transit Line 6 project. The results show that the PSO-LSTM model, with the self-attention mechanism added in, greatly boosts how accurate tunnel settlement predictions are, and the model fits the data better, too. This proves that the PSO-LSTM-SAM model works well: by using the strengths of deep learning, it offers a new way to predict pipeline settlement when building rectangular pipe jacking tunnels.
Chen, Yi, Weng, Xiaoxuan, Zhang, Hong, Li, Yongsuo, Hu, Da
COUPLING, FEMALE, 6 INCH AIR DUCTAS7365/4A (Current)6/23/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
BAND, FEMALE COUPLING, 6 INCH AIR DUCTAS7365/8A (Current)6/23/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
BAND, MALE COUPLING, 6 INCH AIR DUCTAS7365/9A (Current)6/23/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Duct Assembly, Ground, Conditioned Air, Metallic Reinforced, Low Pressure, 350 °FAS7365A (Current)6/11/2026
This Aerospace Standard (AS) defines the requirements for a metallic reinforced, duct assembly suitable for use in low pressure, 350 °F ground heaters.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Effect of Fluid Flow/Time Duration on Static Voltage Generation for Aerospace Hose Assembly2026-26-07576/1/2026
Static electricity is an electrical imbalance on the surface of a material which can interact with other components having same or different materials. Fluid flow within the hose assembly generates static voltage due to friction caused by fluid flow in pipes, that needs to be appropriately quantified and dissipated. Accumulation of such static charge may lead to sudden discharge leading to spark generation. Spark generation around fuel flow might lead to system failure and failure in aircraft engines. Test experiments were conducted to analyze static voltage generated in hose assembly due to fuel flow with the objective that voltage achieved is within the acceptable range to avoid ESD (Electrostatic Discharge) failure. Procedure includes flow rate monitoring and voltage measurement using fuel as test fluid. The testing revealed that the curvature of the hose affects the readings, highlighting the importance of consistent meter alignment. Using a grounding strap is essential to prevent electrical damage and ensure accurate reading. Other functional factors such as proper set up and cleaning methods are crucial were also studied. It's important to check electrical continuity using an ohmmeter before testing. Initial results showed static voltage values beyond acceptable limits which may have resulted in ESD failure. The readings were optimized through electrical grounding and changes in the cleaning process. The revised static voltage readings increased with the flow rate non-linearly emphasizing that voltage testing is critical for aircraft safety.
Waghmare, Shashank
Leveraging Ceramic Matrix Composites (CMCs) for Enhanced Performance in Engine Exhaust and Hot Aero StructuresF-0082-2026-01455/5/2026
This paper discusses the results of the trade study conducted under the Army ManTech-sponsored CH-47 Ceramic Matrix Composite Exhaust Duct Manufacturing Development Program. The program established a baseline using a metallic exhaust duct and compared its weight, cost, manufacturing processes, and ballistic performance to an exhaust duct designed with oxide-oxide ceramic matrix composites (CMCs).
Sisk-Kelley, Jessica, Misciagna, David, Glembocki, Edward, Nevinsky, Michael
Multi-Stage Packaging and Routing Optimization for Automotive Component Layout, Wire Harness and Duct Route Design2026-01-05074/7/2026
Modern vehicle design involves complex considerations and tradeoffs between system integration and layout which have a direct impact on performance, efficiency, and cost. The placement of equipment including control boards, motors, and fans as well as the routing of ducts and wire harnesses poses a time-consuming and intricate problem for design engineers. This paper presents an automated methodology to determine the optimal component packaging configuration, duct routing, and wire harnessing layout to maximize component packing density and minimize the total routing length. A two-stage optimization framework has been developed where the first stage packages the components within the design space with considerations for space utilization, component overlap, proximity relationships, point-to-point accessibility, and component mounting. The second stage implements a custom A* path-finding algorithm and gradient based optimization to determine the optimal route layout between port points. The objective of this work – using A* and gradient based optimization - is to minimize the total length of the duct work and harness layout while respecting proximity, overlap, and accessibility considerations. This paper outlines the methodology and real-world application through the design optimization of an automotive dashboard.
LeFrancois, Richard, Kim, Il Yong
FITTING END, EXTERNAL TAPER PIPE THREAD, DESIGN STANDARDAS5201A (Current)3/13/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
FITTING, CROSS, PIPE, INTERNAL THREADAS4858B (Current)2/12/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
FITTING, NIPPLE, PIPE, EXTERNAL THREADAS4860B (Current)2/12/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
FITTING, ELBOW, 90°, PIPE, INTERNAL THREADAS4856B (Current)1/31/2026
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Human Detection Capacity of Vehicle Front Sonar Sensors in Light and Small Passenger Cars and Minivan2025-22-00091/22/2026
Sonar sensor systems have been developed to prevent collisions between vehicles and surrounding objects by employing ultrasonic sensors mounted at the front of the vehicle. These systems warn drivers when nearby obstacles are detected. However, relatively few studies have examined the capacity of sonar to detect humans. This study aims to clarify the human detection capacity of front sonar sensors installed in two light passenger cars (LPC-I and LPC-II), one small passenger car (SPC), and one minivan (MNV). The LPC-I, SPC, and MNV were equipped with center and corner sensors, whereas the LPC-II had only corner sensors. Three volunteers—a child, an adult female, and an adult male—participated in the study. Human detectability was assessed using the “maximum detection distance ratio,” defined as the ratio of the maximum detection distance for a volunteer to that for a standard pipe. The results showed that both the center and corner sensors consistently detected front- and side-facing human volunteers. For front-facing human volunteers, the maximum detection distance ratios relative to the pipe were 99–101% (child), 93–101% (adult female), and 98–101% (adult male) for the center sonar sensor, and 99–102%, 94–102%, and 96–100% for the corner sensor. For side-facing human volunteers, the corresponding ratios were 97–100%, 92–97%, and 94–99% for the center sensor, and 95–99%, 91–98%, and 93–98% for the corner sensor. These detection ratios were closely aligned with those of the pipe. These findings suggest that front sonar sensors can effectively detect humans prior to vehicle motion initiation, indicating their potential to reduce low-speed vehicle collisions with nearby pedestrians.
Matsui, Yasuhiro, Oikawa, Shoko
A Novel Approach to Optimal Strain Gauge Placement for Structural Assessment: Integrating Looping Configurations with Calibration Techniques2026-26-05511/16/2026
Addressing the challenge of optimal strain gauge placement on complex structural joints and pipes, this research introduces a novel methodology combining strategic gauge configurations with numerical optimization techniques. Traditional methods often struggle to accurately capture combined loading states and real-world complexities, leading to measurement errors and flawed structural assessments [9]. For intricate joints, a looping strain gauge configuration is proposed to comprehensively capture both bending and torsional effects, preventing the bypassing of applied loads. A calibration technique is used to create strain distribution matrices and access structural behavior under different loading conditions. Optimization algorithms are then applied to identify gauge placements that yield well-conditioned matrices, minimizing measurement errors and enhancing data reliability. This approach offers a cost-effective solution by reducing the number of gauges required for accurate stress characterization. This concept is extended to both round and complex-shaped pipes to improve fatigue damage prediction using Road Load Data Acquisition (RLDA). The approach addresses geometric complexities and simulates strain behavior under diverse loading scenarios. The optimization focuses on maximizing strain sensitivity in critical regions, minimizing errors, and ensuring robust strain representation while considering RLDA constraints. The unique contribution lies in directly linking optimized strain gauge placement with improved damage calculation. By integrating RLDA, optimized configurations are tested under actual operating conditions, validating numerical models and assessing damage accumulation based on measured strain data. This leads to more realistic damage predictions compared to simplified loading assumptions. The findings demonstrate that optimized placement significantly enhances damage calculation accuracy, crucial for industries like oil and gas, aerospace, and infrastructure monitoring, where RLDA provides valuable insights into real-world loading.
Shingate, Uttam, Yadav, Dnyaneshwar, Deshpande, Onkar
Investigation of Fatigue Failure Mechanisms in High-Pressure Hydraulic Pipes of Power Steering Systems2026-26-05421/16/2026
The high-pressure steering hose in a hydraulic steering system carries pressurized hydraulic fluid from the power steering pump to the steering gear (or steering rack). Its main function is to transmit the force generated by the pump so that the hydraulic pressure assists the driver in turning the wheels more easily. The high-pressure hydraulic pipeline in the power steering system is a vital component for ensuring optimal performance. During warranty analysis, leakage incidents were observed at the customer end within the warranty period. The primary factors contributing to these failures include pipe material thickness, material composition, mechanical properties, and engine-induced vibrations. This study investigates fatigue-related failures through detailed material characterization and Computer-Aided Engineering (CAE) based on real world usage road load data collected. The objective is to identify the root causes by examining the influence of varying pipe thickness on fatigue life. The investigation discovered that crack initiation predominantly occurred on the concave side of bent pipe sections, specifically on the engine-side high-pressure steering line, which is connected to the power steering pump mounted on the engine. Fracture surfaces exhibited characteristics consistent with fatigue failure, with crack propagation primarily oriented longitudinally along the pipe. The highest tangential stresses were observed on the out word, resulting from the combined effects of internal hydraulic pressure and vibrational loads. Fatigue cracks originated from the inner surface and propagated outward under cyclic stresses induced by pressure fluctuations and engine vibrations during vehicle operation on the road. Computer-Aided Engineering (CAE) simulations indicated that the failure mechanism was primarily attributable to an incorrect material thickness selection during the development phase. Modifications to the pipe design, including increased material thickness, were implemented, leading to improved performance in subsequent testing. The high-pressure hydraulic pipeline exhibits decreased failure rates and improved reliability and durability following the implementation of the revised design.
Survade, Lalit, Koulage, Dasharath Baliram, Biswas, Kaushik
Effect of Pipe Bending by Rotary Tube Bending Process on Durability of Frame Structure2026-26-03701/16/2026
Automobile frames, particularly trellis frame structures, are engineered for superior dynamic performance, with stiffness being a paramount consideration1. These frames frequently utilize welded tubes, a manufacturing process made more complex by the necessity of bending tubes to precise angles to meet packaging and assembly requirements2. This bending, however, induces residual stresses that can substantially compromise the frame's durability3. This investigation employs a detailed finite element simulation to analyse the structural deformation and residual stresses that arise during the bending of Cold Electric Welded (CEW) annealed round pipes4. A comprehensive 3D mechanical model, incorporating realistic tooling and contact interactions, was developed to accurately simulate shape change, ovality, and wall thickness redistribution during the bending process5. CEW pipes, unlike their Electric Resistance Welded (ERW) counterparts, possess minimal initial forming stresses, and the annealing process ensures they are stress-free prior to bending, facilitating a more controlled analysis of their deformation6. The simulation results reveal significant geometric alterations in the bent region, including changes in ovality and wall thickness, which are heavily influenced by the bend radius and angle7. The residual stress analysis indicates a combination of tensile and compressive stresses that could jeopardize the pipe's structural integrity8. Furthermore, deformation in the bend zone can lead to welding issues such as uneven fit-up, altered section modulus, and irregular weld profiles, all of which can diminish weld joint performance9. To address these challenges, a conservative approach was adopted in our fatigue analysis using FE-Safe, applying the lower bound of weld material properties to account for potential weld imperfections stemming from bending10. These simulation outcomes are critical for evaluating the fatigue life of weld joints and comprehending how bending affects the pipe's long-term performance11. Ultimately, this research aims to enhance the reliability and efficiency of piping systems, especially in trellis structures, by improving the accuracy of fatigue simulations12. The insights gleaned will aid in optimizing bending processes, refining weld joint designs, and supporting the development of robust tubular structures for demanding applications13.
Rajwani, Ishwar, Khare, Saharash
Advancing Vehicle-Level AC Thermal Management System Performance2025-28-043410/30/2025
Modern mobility solutions increasingly rely on HVAC systems due to growing transport demands, traffic congestion, and harsh environmental conditions. These systems, comprising a compressor, evaporator, condenser, and thermal expansion valve, require adequate airflow for optimal performance. Insufficient airflow, caused by factors like undersized ducts, improper fan settings, clogged filters, or high static pressures from duct restrictions, significantly hinders cooling capacity. The objective of this study is to develop a predictive model for passenger vehicle AC system performance under controlled environmental conditions. Discrepancies between predicted and desired performance will trigger a structured problem-solving process involving iterative testing, root cause analysis, and the development of corrective measures. The improvements will be focused on the vehicle-level HVAC design, adhering to customer specifications. This research will also establish an experimental validation protocol and offer recommendations for process optimization to reduce prototype/tooling costs in future projects.
Meena, Avadhesh Kumar, Agarwal, Roopak, Sharma, Kamal, Kishore, Kamal
Ultra-Thin Cooling Solution for Mobile Devices Unlocks Slimmer, High-Performance TechnologyTBMG-5391810/1/2025
Scientists from Nagoya University in Japan have developed an innovative cooling device — an ultra-thin loop heat pipe — that significantly improves heat control for electronic components in smartphones and tablets. This breakthrough successfully manages heat levels generated during intensive smartphone usage, potentially enabling the development of even thinner mobile devices capable of running demanding applications without overheating or impeding performance.
Effect of Pressure Losses and Reynolds Number on Active Grille Shutter Characteristics and Its Prediction2025-01-50599/10/2025
In the present article it is investigated why active grille shutters (AGS) can have very different aerodynamic characteristics, ranging from progressive to strongly degressive, and which factors influence them. For this purpose, the authority concept known from the field of heating, ventilation, and air-conditioning (HVAC) is referred to. According to this theory, the control characteristics of dampers depend primarily on the ratio of the pressure losses at the fully open damper to the pressure losses of the rest of the system. The adaptation of the concept to the automotive field shows that, in addition to the pressure losses, the geometry of the cooling air ducting plays a decisive role in motor vehicles. The effect of driving speed and fan operation on the characteristic curves is also being investigated. In addition, authority theory can also be used to derive the conditions under which the opening characteristic curve of an AGS provides a good prediction of the real characteristic curve. And finally, the authority theory offers the possibility of predicting the AGS characteristics in detail. To this end, a concept is being developed that draws on suitable inherent reference characteristics of control dampers from the HVAC sector. The practical application of the concept will be demonstrated using various examples of AGS from real vehicles. The comparison of the predicted characteristic curves with the measured data shows good agreement, with characteristic curve details also being reproduced. A prerequisite, however, is the knowledge of the pressure losses of the AGS in the fully open state as well as the pressure losses of the remaining cooling air duct. For this purpose, a method is shown, which can be used to estimate the relevant pressure losses. Overall, this provides a new calculation method that can be used to estimate the aerodynamic characteristics of AGS in the early development phase of motor vehicles.
Wolf, Thomas
Aerospace & Defense Technology: August 202525AERP088/7/2025
Are Military Avionics Systems Ready for Artificial Intelligence? Reclaiming Readiness: Advancing US Defense Through Scalable Additive Manufacturing When Innovation Outpaces Infrastructure: R&D's New Reality in Aerospace Confidence Through Testing: How to Design a Practical Structural Test Program The Tug-of-War Between Speed and Strength How to strike a balance between cable performance and resilience. 101st Combat Aviation Brigade Makes History with First MUOS Connectivity in a Helicopter New Laser Technique Revolutionizes Ultra-High Ceramic Manufacturing for Spacecraft Researchers have demonstrated a new technique that uses lasers to create ceramics that can withstand ultra-high temperatures, with applications ranging from nuclear power technologies to spacecraft and jet exhaust systems. A Twist in Topology Optimization Leads to High-Performing Heat Exchanger Researchers used an innovative approach to the geometry and design of pipes that flow hot and cold fluids through heat exchangers. New Copper Alloy Could Provide Breakthrough in Durability for Military Systems Army and academic researchers have created stronger, more durable copper that could advance military systems.
Investigation of Expansion Characteristics of Convergent–Divergent Nozzles with a Variable Geometry Sudden Expanded Duct01-18-02-00107/9/2025
In recent years, there has been a significant rise in research focused on estimating the base pressure (Pb) characteristics of convergent–divergent nozzles with sudden expansion regions. This study explores the use of geometrical parameters as a control strategy for nozzles experiencing abrupt expansion at supersonic Mach numbers within an axisymmetric duct. It focuses on four distinct novel expansion duct configurations: square nozzle (SN), step square nozzle (SSN), curved nozzle (CN), and double curved nozzle (DCN). In this work, the high-speed compressible flow investigation is carried out numerically using control volume method on the nozzle with a fixed area ratio (AR) and L/D nozzle. Standard k-ε turbulence model is used in the analysis to access the recirculation region formed near the nozzle walls. The recirculation zone directly influences the Pb and shock cell. For NPR range from 2 to 10, SSN and CN shows an increase in Pb, which further increases the thrust and decreases the base drag provided by the nozzle. The thrust performance analysis shows that at NPR 2, the SN configuration delivers up to 61.8% higher thrust than other nozzles, while at high NPRs (6 to 10), SSN and CN configurations exhibit superior performance with thrust improvements of up to 59.2%. It is also evident that the L/D of the nozzle is also an important parameter that impacts the Pb as well as expansion in the nozzle.
Raj, R. Jini, Kumar, P. Deepak, Panchksharayya, D. V., Kousik Kumaar, R., Praveen, N.
Commercial Vehicle’s Exhaust Front Pipe Reliability Improvement through Virtual Simulation and Experimental Validation2025-01-02096/16/2025
The exhaust front pipe is a critical structural component in commercial vehicles, ensuring the leak-proof flow of exhaust gases into the exhaust after-treatment system while withstanding engine and frame vibrations. To isolate these vibrations, the front pipe is equipped with a flex connector capable of enduring various displacements at frequencies between 8-25 Hz. The position of the flex connector relative to the engine crank axis significantly impacts its structural reliability over its service life. This paper compares the existing design, which features a horizontally positioned flex connector, with a modified design that positions the flex connector vertically and changes the material from SS-304 to SS-321. Finite element analysis was conducted using Nastran software. The fatigue life of the existing flex connector design is approximately 1015 cycles. In contrast, the improved design demonstrates a fatigue life of 1727 cycles, representing a 70% increase in durability compared to the existing design. The newly designed front pipe was then evaluated under the worst-case excitation conditions of 25 mm lateral displacement at 8 Hz frequency using experimental setup. A correlation was established between virtual simulations and experimental validations. Virtual and experimental results conclude that there is a 70% increase in front pipe life when the flex connector is placed vertically with respect to the engine crank axis and SS-321 is used for the flex connector material. This finding is recommended for consideration during vehicle design development.
Chandel, Kushal, Paroche, Sonu, Namdev, Akhilesh, Jain, Shailendra, Patil, Keyur
Robotic System for Infrastructure ReconnaissanceTBMG-532306/1/2025
Innovators at NASA Johnson Space Center have developed a robotic system whose primary structural platform, or “orb,” can be injected into a pipe network and perform reconnaissance of piping infrastructure and other interior volumes. When deployed, this technology uses throttled fluid flow from a companion device for passive propulsion. A tethered line facilitates directional control by the orb’s operator, allowing it to navigate through various piping configurations, including 90° junctions.
Design and Testing of a Ducted Aerial Vehicle for Indoor InspectionF-0081-2025-01065/20/2025
Inspecting the interiors of tanks and ships for defects involves accessing confined and elevated spaces. This can be difficult and hazardous for a person. Ducted aerial vehicles that can hover close to the object of interest can achieve this in a safer and more efficient manner. Such a vehicle is desired to be compact, to have a high hover endurance and to be protected from impact. This paper describes a design concept comprising ducted coaxial counter-rotating rotors with a compact swashplate mechanism for cyclic pitch input to the lower rotor. An experimental setup was used to investigate the effect of the duct. A numerical Blade Element Momentum Theory model was developed and validated to inform rotor selection. A prototype was designed and built with a hover thrust of 9.17 N, outer diameter of 350 mm, and height 173 mm. The duct provided a thrust benefit of 32% for this configuration for a given power. The prototype achieved stable controlled flight in hover and in passing near walls and surrounding obstacles. Some oscillations in attitude were seen in flight. Future work includes improving the control algorithm of the vehicle.
Rahul Yadav, Kunal, Sirohi, Jayant, Purekar, Ashish
GPU-Accelerated Aeroacoustic Simulations of HVAC Duct Configurations2025-01-01335/5/2025
Large eddy simulations (LES) of two HVAC duct configurations at different vent blade angles are performed with the GPU-accelerated low-Mach (Helmholtz) solver for comparison with aeroacoustics measurements conducted at Toyota Motor Europe facilities. The sound pressure level (SPL) at four near-field experimental microphones are predicted both directly in the simulation by recording the LES pressure time history at the microphone locations, and through the use of a frequency-domain Ffowcs Williams-Hawking (FW-H) formulation. The A-weighted 1/3 octave band delta SPL between the two vent blades angle configurations is also computed and compared to experimental data. Overall, the simulations capture the experimental trend of increased radiated noise with the rotated vent blades, and both LES and FW-H spectra show good agreement with the measurements over most of the frequency range of interest, up to 5,000Hz. For the present O(30) million cell mesh and relatively long noise data collection of 0.5s, the simulation results can be obtained in about 6 hours on 8 standard GPUs. Accurate and efficient numerical predictions of the SPL from HVAC ducts would allow automotive manufacturers to assess different duct configurations in the early design cycles and avoid the costly countermeasures necessary when excessive noise is observed in the experimental phase of the final design.
Besem-Cordova, Fanny M., Dieu, Donavan, Wang, Kan, Brès, Guillaume A., Delacroix, Antoine
Evaluation of Hybrid Aeroacoustics Models for HVAC Duct Noise Predictions2025-01-50325/1/2025
This study evaluates the effectiveness of two hybrid computational aeroacoustic methods—Lighthill wave model and perturbed convective wave model—in simulating HVAC duct noise in the automotive industry. Using component-level acoustic testing of a Ford HVAC duct, simulations were conducted at varying airflow rates to assess the accuracy of both models in predicting duct noise. The Lighthill wave model, suitable for noise analysis in regions outside turbulent flow areas, showed a good correlation with experimental data, especially in the frequency range of 100 Hz–5000 Hz, but sometimes struggled with pseudo-noise effects at low frequencies near turbulent regions. The perturbed convective wave model, which is suitable for noise analysis anywhere in the flow domain, underpredicted sound pressure levels at low frequencies as well. Both models underpredicted high-frequency noise (>5 kHz) due to insufficient mesh and time-step sizes. Despite these limitations, the Lighthill wave model provided better overall agreement with experimental results. The analysis also identified a resonance peak at 160 Hz, captured in both simulations and experimental data, offering valuable insights for further optimization. These findings underscore the potential of hybrid aeroacoustic models to improve the design of quieter HVAC systems, enhancing both vehicle comfort and customer satisfaction.
Nam, Jee-Whan, Mendel, Marc, Golberg, Igor
Automatic Generation of HVAC Ducting System Designs Using Topology and Shape Optimization2025-01-86564/1/2025
In this paper, the topology and shape optimization of a vehicle Heating, Ventilation, and Air Conditioning (HVAC) system is presented. The CFD and optimization methodologies are implemented within AcuSolve™ software. The topology optimization algorithm computes the geometry, where the design domain is parameterized with a field of porosity design variables which indicates the material, fluid or solid, throughout the domain. The optimization is performed using the continuous adjoint approach by the Galerkin Least Squares solver on which the AcuSolve™ solver is based. The design is further improved by using shape optimization. To optimize the geometrical shape, a combination of smooth perturbations, in terms of so called morph shapes, are used to deform the geometrical shape in the optimization algorithm. To this end, a parameterization of the design space is done using a moderate number of design variables, each associated with a morph shape. The two optimization phases are connected by means of automatic computation of the morph shapes from the topologically optimized geometry and the flow field. The topology and shape optimization methods are applied to the design optimization of a car HVAC ducting system for minimum power dissipation and minimum fluid volume constrained by specified flow rates at the exits of the ducts.
Papadimitriou, Dimitrios, Sandboge, Robert
Numerical Analysis of Capillary Performance of Various Lattice Structures for Vapor Chamber Application2025-28-00622/7/2025
Additive manufacturing has made it possible for the design of increasingly complex structures that require precise manufacturing. This may be particularly beneficial for heat pipe and vapor chamber design – particularly for the wick structure, a very important component. This study uses numerical simulation to analyze three different types of lattice structures of increasing complexity, in terms of their capillary performance. This is one of the most important parameters which determine the wick efficacy. Simple cubic, Column and Octet lattice models are computationally designed and CFD is used to simulate capillary action in a pipe of 0.4 mm inner radius for 2 milliseconds, after validation of the numerical model with existing experimental results. It is found that the Octet lattice (with the most complex inner structure) has the greatest capillary rise in the same amount of time. The rate of rise is not uniform for any structure, but is highest for Octet. This study demonstrates the feasibility of CFD analysis of architected materials and other complex structures, and the efficacy of lattice structures as heat pipe and vapor chamber wicks, with the advantages of additive manufacturing.
Sundararaj, Senthilkumar, Hudge, Ajay, Basuroy, Suhashini, Kang, Shung-Wen
Temperature Reduction of Servo Oil Used in Steering System Using Pulsating Heat Pipe2025-28-01042/7/2025
There are various steering technologies are available in market nowadays. Hydraulic Power Steering (HPS) is one of them. As hydraulic name is linked to it the temperature role comes to play. While doing hard cornering the hydraulic oil used to assist the working in steering system get over heated, due to which oil loses its viscosity became one of the major causes of hard steer in trucks. Also, due to limited space the large heat exchanger cannot be used there. So, objective of this Thesis is to examine an effective solution which can be compact in design and at the same time should be effective to solve this problem. After going through literature analysis, we finalize that the Principal of Pulsating Heat Pipe could be a possible solution. So, for that we design different model based on previous research work in Creo and simulate them in Star CCM+ to finalize the optimality.
Saikrishna, VNL, P, Rudresha, Yadav, Satyendra, B, Ruthvika, Vishwasa, Viditha
Design and Performance Optimization of Automotive Thermoelectric Generator System Integrated with Heat Pipes2025-01-70601/31/2025
In the field of static power generation, thermoelectric technology has become an important solution for utilizing automotive exhaust waste heat. This study presents a new design for a heat exchanger integrated with heat pipes, aimed at augmenting the installation area of thermoelectric modules and improving the hot end temperature by high heat transfer rate. Moreover, the number of heat pipes in each region is optimized to reduce the temperature gradient along the direction of exhaust flow and maximize overall output performance. A comprehensive numerical model of the thermoelectric generator system is developed to conduct the performance prediction and parameter optimization. The results reveal that the integration of heat pipes substantially boosts the performance of the automotive thermoelectric generator system, characterized by enhanced heat transfer, increased power output, and improved conversion efficiency. And the optimization yields an optimal configuration with 5 heat pipes per thermoelectric module. Under the test conditions of an exhaust temperature of 600 K and a mass flow rate of 30 g/s, the new automotive thermoelectric generator system demonstrated an output power of 146.28 W and an output voltage of 166.26 V. These outputs represent a remarkable increase of 53.76% and 75.16%, respectively, compared to the conventional one without heat pipes. This work not only underscores the potential of heat pipe integration in thermoelectric systems but also offers a foundational framework for the optimal design of automotive thermoelectric generator systems equipped with heat pipes.
Zhao, JinFu, Ding, Renkai, Chen, Jie, Wang, Ruochen, Luo, Ding
Automatic Hose Cutting Machine for Small Scale Industries2024-01-521712/10/2024
The goal of this work is to increase the accuracy and efficiency of hose cutting operations in small scale industries is by designing and building an automatic hose-cutting equipment. The device uses a computer-controlled system to autonomously cut pipes of various sizes and lengths. By means of a stepper motor-driven, rapidly spinning blade, the cutting process is accomplished. Additionally, the machine has sensors that measure the hose's length and modify the cutting position as necessary. Premium components and materials are used in the machine's construction; these are chosen for their performance and longevity. The device is able to boost cut precision and raise industry production all around from 100% to 190% efficient system thereby decreasing labor and time needed for hose cutting operations.
Feroz Ali, L., Manikandan, R., Madhankumar, S., Sri Hari, P., Suriya Prakash, T., Vishnu Doss, G.
Development of a Method to Model Flexible Hose in FE Linear Dynamics Simulations2024-28-025412/5/2024
Linear dynamics simulations are performed on engine components to ensure structural integrity under dynamic loading. The finite element model of the engine assembly must be prepared accurately to avoid under or over design of the engine components. Flexible hoses are present at pipe routings and modeling them in simulations is a challenge because the stiffness of the composite is not known. The hose under study in this paper is a rubber composite with a knitted reinforcement layer. A multiscale modelling approach is presented to characterize the hose stiffness. A representative volume element geometry i.e., unit cell representation of the composite, consisting of the knitted yarn and surrounding rubber is used to establish orthotropic elastic properties at microscale, by performing finite element homogenization using the ANSYS material designer module. The homogenized properties are assigned to the macroscale hose geometry to perform modal analysis simulation in free-free and fixed-fixed condition. To validate the finite element model, experimental modal analysis is performed on the hose with the same boundary condition. Fundamental natural frequencies and mode shapes obtained from simulations and experiments are compared which shows good agreement. A predominantly automated approach to characterize the stiffness of the hose is presented and it is suggested that the hose shall be modelled using orthotropic elastic properties in linear dynamics simulations for a more accurate finite element model.
Ashodiya, Jay Virendra, Jayachandran, Janarthanan, Santhosh, B
Numerical Investigation on Performance Based Methodology for Developing Vane Design of AC Duct2024-28-000410/17/2024
Airflow directionality in a vehicle cabin is one of the concerns of car owners, researchers, and vehicle manufacturers. After exposed/parked in hot ambient condition for a long time, HVAC system normally takes few minutes to cool down and reach an acceptable cabin temperature for the passenger comfort. To ensure proper airflow distribution inside the cabin, the AC duct & vanes ability to direct airflow must be evaluated. Objective of this work is to propose a methodology for developing the vane design of AC system duct using CFD approach. Two different goals are attempted. Firstly, the effect of horizontal and vertical vane angle on airflow directionality is investigated with DoE approach. Then factors influencing the airflow directionality are investigated using factorial study approach. CFD based factorial analysis (L9 orthogonal array) was conducted using three components at three levels. The impact of number of horizontal vanes, number of vertical vanes and distance between them on the pressure drop and face level velocity are investigated. One of the parameters required to freeze vane design is attaining higher face velocity and lower vent pressure drop. New methodology is proposed in this work to choose the required number of horizontal and vertical vanes of automotive AC system duct/vent assembly based on their airflow directing ability.
Mahesh, A, Baskar, Subramaniyan, Raju, Kumar, Gopinathan, Nagarajan
Design Optimization of Air Duct for Noise Reduction Using Gaussian Process Regression Algorithm2024-28-004210/17/2024
In the context of Battery Electric Vehicles (BEVs), airborne noise from Heating, Ventilation and Air Conditioning (HVAC) ducts becomes a prominent concern in the view of passenger comfort. The automotive industry traditionally leverages Computational Fluid Dynamic (CFD) simulation to refine HVAC duct design and physical testing to validate acoustic performance. Optimization of the duct geometry using CFD simulation is a time-consuming process as various design configurations of the duct have to be studied for best acoustic performance. To address this issue effectively, the proposed a novel methodology uses Gaussian Process Regression (GPR) to minimize duct noise. Present solution demonstrates the power of machine learning (ML) algorithms in selecting the optimal duct configuration to minimize noise. Utilizing both real test data and CFD results, GPR achieves remarkable accuracy in design validation, especially for HVAC air ducts. The adoption of GPR-based ML algorithms significantly enhances the accuracy and cost-effectiveness of air duct design. This approach accelerates the development process, ensuring quicker design optimization. Present article focus on an efficient solution for rapidly achieving optimized acoustic designs, surpassing conventional validation methods. ML techniques, particularly GPR provides an optimal solution for improving the passenger comfort in the car.
Althi, Tirupathi Rao, Manuel, Naveen, K, Manu
Characterization of HVAC Noise and its Dynamic Interplay within the Vehicle's Environment2024-28-01139/19/2024
Vehicle HVAC noise performance is an important vehicle design validation criterion since it significantly links the brand image of a vehicle. It affects the customer’s buying decision and the business of selling vehicles because it directly affects driving comfort. Customers expect continuous improvement in HVAC noise without compromising cooling performance. The process of cascading vehicle-level acoustic performance to subsystem and component levels becomes an important factor in the vehicle NVH development process. It was found that the component-level [HVAC unit without duct] performance of an HVAC system measured in an anechoic chamber was at par when compared to targets, whereas the subsystem-level performance [HVAC unit with duct and dashboard] was on the higher side of the targets. Advanced NVH tools were used to identify the source of noise at the subsystem level. It helped to locate the source and its transfer path. A design modification done at the transfer path location gives a good improvement in HVAC noise at the subsystem level. However, when the same HVAC system was tested at the vehicle level, it showed an increase in noise as compared to the subsystem level. A detailed study was conducted to understand the acoustic behaviour of the vehicle environment. HVAC systems tested in an anechoic chamber and in a car are in a free-field and diffuse-field environment, respectively. In free-field sound propagation, there are no reflections, whereas in diffuse-field sound, it is reflected in many times that it travels in all directions with equal magnitude. Additionally, this paper encompasses a methodology aimed at attaining a less diffused field and fostering a more open environment within the vehicle, ensuring that HVAC performance measured at the subsystem level aligns with integration within the car.
Titave, Uttam Vasant, Kalsule, Shrikant, Naidu, Sudhakara
A Study to Establish an Evaluation Method for Selecting Suitable Packing Adhesives for A/C Ducts to Ensure Sustained Adhesiveness in Thermal and Condensation Conditions over the Vehicle's Lifetime2024-28-00969/19/2024
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water contacts electrical components beneath the ducting, or loss of thermal energy, thereby reducing the AC system's thermal efficiency. This paper primarily focuses on developing an experimental methodology to identify the most appropriate adhesive for use in ducting applications. This involves a detailed examination of various adhesive types and designing suitable experiments to evaluate the adhesive bond's resilience, particularly when applied to HDPE blow-molded ducts. The methodology aims to ascertain the conditions under which the adhesive bond fails, ensuring that the selected adhesive can maintain its integrity under the rigors of operational stress and environmental factors. Additional insights gained from the study highlight the influence of surface roughness, resting time, and exposure to extreme temperatures on the lamination quality of duct packing. These findings are crucial for manufacturers to consider when selecting adhesives for AC duct systems, ensuring that the chosen solutions are robust enough to withstand the demanding conditions of automotive environments and maintain the integrity and functionality of the duct packing over time.
M, Amala Rajesh, Sonkar, Surabhi, Kumar, Mukesh
Enhanced Thermal Management in Oil Spray-Cooled Motors: A Novel Approach to Replacing NTC Sensors14-14-01-00058/12/2024
Motor temperature plays a critical role in controlling pump speed and regulating coolant flow to prevent overheating during motor operation. Presently, negative temperature coefficient (NTC) sensors are commonly used for motor temperature measurement, typically installed at the motor winding’s end for ease of installation. However, in oil spray-cooled motors, the temperature distribution is uneven due to the spray pipe, leading to lower temperatures near the pipe compared to other areas. This results in a challenge where relying solely on NTC measurements at the winding end may not meet the motor’s cooling requirements. To address this issue and improve temperature signal accuracy, a novel approach has been developed that utilizes four signals derived from the motor controller: motor speed, motor torque, along with oil pump speed, oil temperature. Employing the lumped parameter method, a model established in Simulink aims to estimate the average temperature in the motor’s high-temperature region. Subsequently, this value is corrected and directly utilized as an input signal for motor thermal management. The proposed approach not only enhances motor temperature monitoring accuracy but also mitigates operational risks, thereby prolonging motor lifespan and enhancing its overall safety.
Lu, Junjie, Li, Qiang, Chen, Binglin, Zhu, Lunzhi, Wu, Jian, Yan, Pingtao
Research on the Forming Process of Bimetal Composite Pipe by Hydroforming2024-01-50011/15/2024
Bimetal composite pipe has higher strength and is more corrosion and high temperature resistant compared to single metal pipe, making it a new type of pipe that is being gradually applied to important industrial fields such as aviation and aerospace manufacturing. To study the hydraulic forming mechanism of bimetal composite pipes, the forming process is divided into three stages: liner pipe elastic–plastic deformation, base pipe loading, and unloading. The stress and strain relation between the liner and base pipe during the gradual increase in hydraulic pressure is analyzed, and the range of selected internal pressure required for composite pipe formation and the relation between residual contact pressure and internal pressure for the liner–base pipe interface are obtained. The accuracy of analytical predictions for the contact pressure and the axial and circumferential strains on the outer wall of the base pipe during the forming process is verified through numerical simulation and composite pipe forming experiments. Through this analysis, the appropriate internal pressure for forming can be selected and the residual contact pressure between the layers can be effectively regulated to ensure quality formation of composite pipes, depending on different materials and working conditions. Effective guidance for production practices can be provided by theoretical analysis and numerical simulation during the development of bimetal pipe composite process.
Tang, Yue
Hydraulic Flanged Tube, Pipe, and Hose Connections, Four-Screw Flange Connection - Part 2: 42 MPa (Code 62)J518/2_202312 (Current)12/26/2023
This SAE Standard covers general and dimensional specifications for the Code 62 metric (Type 1) and inch (Type 2) flanged heads, flange clamps (FC and FCM), and split flange clamps (FCS and FCSM) applicable to four-screw flange type tube, pipe, and hose connections. Also included are the recommended port dimensions and port design considerations. Type 2 (inch) flange clamps and split flange clamps are not for new design. The flanged heads specified are incorporated into fittings having suitable means for attachment of tubes, pipes, or hoses to provide connection ends. These connections are intended for application in hydraulic systems, on industrial and commercial products, where it is desired to avoid the use of threaded connections. The rated working pressure of an assembly shall not exceed the least of all the component working pressure rated values. The following general specifications supplement the dimensional data contained in the tables with respect to all unspecified detail. Parts manufactured to this standard are interchangeable with ISO 6162-2 and connectors to either standard can be supplied with the exception of the -40 and -48 Type 2 connections that are included in SAE J518-2, but not ISO 6162-2.
Hydraulic Hose and Hose Fittings Committee
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