Browse Topic: Valves

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Vibration Modeling and Analysis of Pipeline- Clamped Systems for Aircraft Landing Gear2026-01-0215To be published on 04/07/2026
Fluid pulsation within the aircraft landing gear hydraulic pipeline system can lead to severe damage to system structures such as valves, joints, and supports. Previous research has predominantly focused on investigating the vibration characteristics of the pipelines themselves, often neglecting the frequency-dependent characteristics of clamps. For the dynamic modeling of clamped pipeline systems, accurately obtaining the dynamic response of the clamps is of significant importance.This study establishes the vibration differential equations for the hydraulic pipe-clamp rigid-flexible coupling nonlinear system. The frequency-dependent dynamic properties of flexible clamps are considered based on fractional derivative theory, and the parameters of the clamp's dynamic model are identified using a genetic algorithm. Taking into account the flexible constraint of the clamps, a fluid-structure interaction frequency-domain solution method for the hydraulic pipeline-clamp system is
chang, Hailin, Zhu, Hengjia
Development of A Tire Blowout Experimental Platform for Dynamics and Control Validation2026-01-0202To be published on 04/07/2026
Tires are critical to vehicle dynamics, transmitting traction, braking, and cornering forces to the road. A tire blowout, the sudden and rapid loss of inflation pressure due to puncture or structural failure, can cause severe instability, rollover, or collisions. Understanding vehicle response during blowout events is essential for developing robust safety systems and control strategies. Earlier developed simulation models are used to study and understand vehicle behavior during blowouts, but there is a lack of on-road testing platforms to validate these models experimentally. A custom-built blowout device integrated with a data acquisition system has been developed to address this gap. It consists of multiple solenoid valves mounted on the wheel surface and powered by a 12V supply. All valves are triggered at the same time using an RF remote, producing rapid and synchronized deflation. An Arduino-based actuation system is being developed for individual valve actuation and custom
KANTHALA, Maha Vishnu Vardhan Reddy, Krishnakumar, Ashwin, Lin, Wen-Chiao, Chen, Yan
Design and validation of modern hydrogen and natural gas containers for on board vehicle storage2026-01-0188To be published on 04/07/2026
Ensuring the operational safety of gaseous fuel containers for hydrogen and natural gas vehicles requires robust and validated protective devices capable of responding reliably under diverse operating and accident scenarios. This paper presents the design considerations, test methodology, and validation outcomes for safety subsystems integrated into modern compressed gas storage vessels, with emphasis on pressure relief devices (PRDs), thermal protection systems, and valve assemblies. Drawing on experimental insights from previous studies of hydrogen and natural gas fueling systems and fire-resistance assessments, the work defines safety-critical conditions such as rapid temperature rise during bonfire exposure, localized flame impingement, over-pressurization from fast filling, and mixed-gas operation. A comprehensive validation protocol was established, combining standardized regulatory tests with additional stress profiles replicating service-realistic environments. These included
Flekiewicz, Marek, Flekiewicz, Wojciech
Development and Preliminary Combustion Experiments of a Prototype Engine with Sleeve Valves Based on the Focusing Compression Principle2026-01-0295To be published on 04/07/2026
Our laboratory has proposed the focusing compression principle which employs pulsed super-multi jets of gas colliding around the chamber center. This principle aims to achieve high thermal efficiency by reducing both exhaust and cooling losses. Exhaust loss is minimized due to relatively-silent high compression. Cooling loss is reduced due to thermal insulation caused by fuel-air mixture being confined to the chamber center and the compressible flow effect. In previous studies, we conducted fundamental gasoline combustion experiments on a proof-of-concept opposed-piston engine which incorporated this principle. This engine featured eight intake nozzles in an octagonal configuration and utilized non-sinusoidal and strongly asymmetric piston movements. The results indicated the possibility of high thermal efficiency based on less knocking under high compression, and the potential for stable combustion under lean-burn conditions. As a next step towards practical application with
NISHIZAWA, Tomohiko, Naitoh, Ken, baba, Shotaro, Ukegawa, Hiraku, Yamada, Sota, Ozono, Yuka, Abiko, Mirei, Suzuki, Yosuke, Hara, Namito, Ito, Yoshikuni, Matsubara, Kosaku, Uenoyama, Kazuyuki
CFD-Based Investigation of Fuel Tank Sloshing: Crash Safety and Noise Concerns2026-01-0490To be published on 04/07/2026
A computational study using the Volume of Fluid (VOF) method in SimericsMP+ was conducted to investigate fuel sloshing in automotive fuel tanks under both crash and sudden stop conditions. The SEALs method was employed to rapidly generate the fuel tank mesh, enabling efficient simulation setup. At the outset, a benchmark sloshing case was simulated and compared against experimental data, showing excellent agreement to validate the simulation method. This simulation method was then applied to the fuel tank sloshing scenarios mimicking crash and sudden stop conditions. The study initially focused on a crash scenario where fuel waves impact valves, pumps, and other internal structures. Capturing these localized impact forces is critical for evaluating the risk of component failure and potential leakage. A baffle-equipped tank was simulated and compared with sensor data. Results show that the computed shock forces on valves and baffles closely matched the measurements, demonstrating the
Jia, Kun, Rahman, Ashique
Research on Characterization Parameters for Engine Valve Clearance Based on Vibration Signals2026-01-50052/2/2026
To address mechanical faults caused by abnormal engine valve clearance, this study investigates the extraction methods of vibration signal feature parameters. A six-cylinder diesel engine test bench was established to collect cylinder head vibration signals under varying rotational speeds, torque loads, and valve clearance conditions. Four time–domain parameters, including peak-to-peak values, rectified average values, standard deviations, and root mean square amplitude, were extracted alongside the energy distribution of frequency bands obtained through wavelet packet decomposition. The correlations between these parameters and valve clearance states were systematically analyzed. The results demonstrated that all parameters exhibited significant increasing trends with elevated rotational speeds, whereas torque variations exerted minimal influence. Abnormal valve clearance induces significant amplitude increases in time–domain parameters. The energy within frequency bands 5–8 (6–12 kHz
Ji, Shaobo, Dong, Yiming, Yue, Yuanhang, Pan, Chi, Liao, Guoliang, Lu, Yueqi
Guide for Qualification Testing of Aircraft Air ValvesARP986D (Current)1/21/2026
This SAE Aerospace Recommended Practice (ARP) defines recommended analysis and test procedures for qualification of pneumatically, electrically, manually, and hydraulically actuated air valves. They may be further defined as valves that function in response to externally applied forces or in response to variations in upstream and/or downstream duct air conditions in order to maintain a calibrated duct air condition (e.g., air flow, air pressure, air temperature, air pressure ratio, or air shutoff). Qualification testing performed on the airplane to verify compatibility of the valve function and stability as part of a complete system is outside the scope of this document. Refer to ARP1270 for design and certification requirements for cabin pressurization control system components. As this document is only a guide, it does not supersede or relieve any requirements contained in detailed Customer specifications.
AC-9 Aircraft Environmental Systems Committee
Safety Locking and Alert System for Container Trailers with Geo Fencing2026-26-02731/16/2026
The Container trailers are used worldwide to transport goods & materials especially e-commerce applications with valuable materials. These container trailers are presently locked with a mechanical locking system and often broken and unlocked by unauthorized people. During transportation time, the driver stops the vehicle for natural calls, food or any other breakdown, the attempt is made to steal the materials. Many cases were known only after damages are done. It has become a serious issue nowadays in the transportation industry. To avoid these problems, we have designed and developed a system that operates pneumatically with digital locking control. The system is designed to ensure proper safety by rigid mechanical locking. It is actuated by a pneumatic system consisting of Directional control valve & pneumatic cylinders. The lock and unlock inputs are given through digitally and the digital controller provides the appropriate input to solenoid operated direction control valve. Based
kumaran, Rajasekar
Systemic Modelling and Simulation Approach to Estimate Brake Response Time in a Pneumatic Brake Systems2026-26-04691/16/2026
Brake response time in truck air brake systems is crucial for ensuring safety and operational efficiency. This paper details the development of a simulation model aimed at fulfilling all regulatory requirements for brake response time, as well as serving as a tool for stopping distance calculations. The actual pneumatic circuit, including brake valves, relay valves, brake chambers, and plumbing have been replicated. The aim is to use 1D simulations to predict the response time compliance during the pressurizing phase (when brakes are applied) of the brake system. A mathematical model is developed using a commercially available 1D simulation tool. This model employs a lumped parameter approach for the pneumatic components, with governing equations derived from compressible flow theory and empirical valve flow characteristics. The simulation outcomes provide detailed response time and pressure build-up profiles. Validation against 201 vehicle test cases showed 96% of simulations within
Kumbar, Praful, Murugesan, Karthik, Shannon, Rick
Rear Wiper Motor with Nozzle Integration2026-26-06001/16/2026
In today's dynamic driving environments, reliable rear wiping functionality is essential for maintaining safe rearward visibility. This study sharing the next-generation rear wiper motor assembly that seamlessly integrates the washer nozzle, delivering improved performance alongside key benefits such as better Buzz, Squeak, and Rattle (BSR) characteristics, reduced system complexity, cost savings, and enhanced perceived quality. This integrated design simplifies the hose routing which improves the compactness and the efficiency of the design. This also enhances the spray coverage and minimizes the dry wiping unlike the traditional systems that position the washer nozzle separately. A non-return valve (NRV) is incorporated to eliminate spray delays ass it maintains consistent water flow giving cleaning effectiveness. Since this makes the nonfunctional parts completely leak proof due to the advanced sealing, it increases the durability and reliability in long run. As this proposal offers
Dhage, Prashant, K, Nagarajan, G, Sabari Rajan
Architecting ATA 28 with Model-Based Systems Engineering: Center of Gravity Balance and System Performance01-18-03-00151/7/2026
The fuel management system for a fixed-wing aircraft has been developed and explored with the model-based systems engineering (MBSE) methodology for maintaining the center of gravity (CoG) and analyzing flight safety. The system incorporates high-level modeling abstractions that exploit a mix of behaviors and physical detail resembling real-world components. This approach enables analysis for a multitude of system requirements, verification, and failure scenarios at high simulation speed, which is necessary during system definition. Initially, the CoG is maintained by directly accessing the flight deck valves and pumps in both wings and controlling them through the bang-bang control law. In the refinement phase of the fuel system controller, the manual and individual controls of the valves and pumps are replaced with an autonomous fuel transfer scheme. The autonomous scheme achieves no more than a 20 kg difference in fuel between the wings during normal conditions. In the event of
Zaidi, Yaseen, Michalek, Ota
Methods for Evaluating Cryogenic FiltersARP900C (Current)1/1/2026
The purpose of this document is to present test methods that can be utilized to evaluate the filtration and operating characteristics of filters that will be utilized in a cryogenic system. The methods presented herein are intended to supplement standard filter testing specifications to allow evaluation of filter performance characteristics in areas that could be affected by extreme low temperatures.
A-6C1 Fluids and Contamination Control Committee
Optimizing Engine Dynamics with Hydraulic Lash Adjusters in Type-5 Valvetrain Systems2025-28-023511/6/2025
For the diesel engines first designed & developed before 2000s, push-rod type valvetrains with mechanical valve lash adjustment were common. For one such legacy diesel engine, first developed for tractors and now applicated for on road vehicles, having push-rod valvetrain architecture & mechanical valve lash adjustment (Type-5 valvetrain system) with flat follower tappet, integrating HLAs for enhancing the NVH & serviceability presented certain challenges. This paper delves into the challenges faced in the design & development phase of HLA integration project on a four-cylinder diesel engine. For integration of HLA, first, the packaging evaluation of valvetrain assembly was done followed by oil flow assessment and necessary changes in the oil pump and circuit. Then, valve lift profile optimizations were done since the ramp rate & seating velocity requirements are different for valvetrains with mechanical lash and HLAs. Numerous iterations were performed for cam-profile design to
John, Shijino Shaji, Bagal, Pratik
PTO Clutch Hydraulic Performance Evaluation Methodology Development & Correlation2025-28-029511/6/2025
This paper presents an analysis methodology developed to comprehend the impact of pressure spikes in off-highway applications, particularly during PTO (Power Take-Off) clutch engagement. These pressure spikes can adversely affect hydraulic subsystem components such as seals, gaskets, and valve operations. Assessing hydraulic system performance through physical trials can be cumbersome, resulting in longer development times and increased costs. To address this, a methodology was developed in a virtual environment to evaluate hydraulic system performance. The virtual method outlined in this paper is created in a 1D environment using a simulation methodology to replicate the transient behavior of the dynamic system. The hydraulic system primarily includes a relief valve, solenoid valves, a pump, and a clutch. An analytical model was developed for the hydraulic system components with appropriate fidelity to accurately replicate the transient behavior and magnitudes of pressure spikes. This
Memane, Nilesh, Kumar, Suneel, Veerkar, Vikrant
Advanced 3D Simulations of a Four-Stroke High-Performance Engine Valvetrain for the Analysis of the Mechanical Stresses and Energy Losses2025-32-001011/3/2025
Enhancing the performance of naturally aspirated 4-stroke engines relies heavily on improving trapping efficiency, increasing maximum engine speed, and reducing friction losses. In this regard, the valvetrain plays a critical role. Achieving high volumetric efficiency at higher engine speeds necessitates very steep valve opening and closing ramps, making this aspect pivotal in the design process. At high engine speeds, significant dynamic phenomena arise, including valve float during the lift phase and valve bounce during the closing phase. These effects not only induce substantial modifications to the valve lift curve but also increase the mechanical stress on critical components such as the valve and the rocker arm, thereby elevating the risk of failure. Moreover, the timing system substantially contributes to overall engine losses due to frictional energy dissipation, which results from the numerous interactions between moving components. The present work aims to develop a numerical
Tarchiani, Marco, Pizzicori, Alessio, Raspanti, Sandro, Romani, Luca, Meli, Enrico, Ferrara, Giovanni, Trassi, Paolo
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
Meena, Avadhesh Kumar, Agarwal, Roopak, Sharma, Kamal, Kishore, Kamal
Valve Wagging Prediction Methodology for Engine Brake Application2025-28-040210/30/2025
Eaton's decompression engine braking technology for medium and heavy-duty diesel engines delivers high braking power and provides several advantages to the commercial truck owner. Eaton offers rocker arm-based 1 stroke, 1.5 stroke, and 2 stroke systems for overhead cam and cam in block engine architectures. The Compression Release (CR) engine brake avoids overheating and fading of primary friction brake. It reduces or eliminates the need for a driveline retarder. One of the failure modes for Engine Brake (EB) system is excessive lateral displacement of the exhaust valve, caused by non-uniform pressure distribution across the valve during Brake Gas Recirculation (BGR) and Compression Release modes. This excessive deformation is referred to as Valve Wagging. Valve wagging significantly affects the structural stability of the engine brake mechanism. Analyzing its behavior is essential to minimize excessive wear on valve guide and Valve Seat Insert in new designs. Since evaluating the
Soni, Lalitkumar R., Joshi, Himanshu, J, Gokulakrishnan, De Giovanni, Pierfrancesco
FITTING END, INTEGRAL CENTERED WELD LIP, DESIGN STANDARDAS4697C (Current)10/21/2025
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Study on the Fracture Failure Problem of the Height Valve Regulating Rod2025-99-007510/17/2025
The height valve adjusting rod is an important part of the suspension system, used to adjust the height of the train to adapt to the train through the curve, slope or uneven track when the height valve adjusting rod fracture failure, the train’s suspension system can not be adjusted normally, may lead to the height of the train is too high or too low, affecting the stability of the train and the driving safety. In this paper, an underground vehicle height valve adjusting rod fracture failure of the problem was studied and analysed, the specific conclusions are as follows: height valve adjusting rod there are two main vibration frequency, 60Hz and 340Hz, 60Hz main frequency has always existed, and 340Hz vibration frequency are present in part of the interval, but also caused by the vehicle vibration of the main reason for the local larger; height valve adjusting rod stress there is also a significant vibration The main frequency of 340Hz, similar to the vibration characteristics of the
Wang, Chao, Yang, Chen, Pan, Minkai
LES and RANS Modeling of a Hydrogen Low-Pressure Direct-Injection Injector2025-24-00669/7/2025
Hydrogen direct injection is a promising strategy for enabling high-efficiency, low-emission powertrains. However, challenges related to mixture stratification and jet modeling persist, particularly under engine representative conditions. This study numerically investigates a simplified injector model, focusing on the downstream hydrogen jet behavior from of a hydrogen low-pressure direct-injection jet-forming cap under both constant-volume chamber (CVC) and engine conditions. The primary objective is to evaluate numerical methodologies and explore model simplification strategies that remain computationally feasible while preserving physical fidelity—particularly relevant for early-stage hydrogen injector development. Experimental data serve as validation benchmarks across operating regimes. In the CVC platform, large eddy simulations (LES) provide turbulence-resolving insights that inform the refinement of Reynolds-averaged Navier–Stokes (RANS) models. RANS simulations are then
Menaca, Rafael, Liu, Xinlei, Silva, Mickael, Wu, Hao, Ben Houidi, Moez, Mohan, Balaji, Cenker, Emre, AlRamadan, Abdullah, Syed, Iltesham, Pei, Yuanjiang, Roberts, William, Im, Hong G.
Dynamic Analysis of Intake and Exhaust Valve Motion in a High-Performance 4-Stroke Engine. Part1 - Experimental Measurement of Valve Motion Using a High-Frequency Laser Sensor2024-32-00834/18/2025
The motion of the intake and exhaust valves plays a pivotal role in determining operational efficiency and performance, especially in high-specific power 4-stroke engines. At high rpm levels, the dynamic behavior of the valve may deviate from the kinematic model established during the design phase. This discrepancy arises due to the high accelerations and forces to which the valve and other components of the valvetrain system are subjected. Notably, under such conditions, the valve may detach from the cam profile at the conclusion of the opening stroke and can exhibit a bouncing behavior during the closing stroke. Moreover, the elasticity of all valvetrain system elements introduces additional complexities. Factors such as timing chain elongation, camshaft carrier deformation, and valve stem compression can contribute to a deviation in phase compared to the initially defined kinematics. Within this context, the direct measurement of the valves motion represents fundamental information
Grilli, Niccolò, Romani, Luca, Raspanti, Sandro, Bosi, Lorenzo, Ferrara, Giovanni, Trassi, Paolo, Fiaschi, Jacopo, Guarducci, Edoardo
Design Optimization of Electro-Hydraulic Valve Performance Through Simulation and Experimental Methods2025-01-86424/1/2025
The main purpose of the semi-active hydraulic damper (SAHD) is for optimizing vehicle control to improve safety, comfort, and dynamics without compromising the ride or handling characteristics. The SAHD is equipped with a fast-reacting electro-hydraulic valve to achieve the real time adjustment of damping force. The electro-hydraulic valve discussed in this paper is based on a valve concept called “Pilot Control Valve (PCV)”. One of the methods for desired force characteristics is achieved by tuning the hydraulic area of the PCV. This paper describes a novel development of PCV for practical semi-active suspension system. The geometrical feature of the PCV in the damper (valve face area) is a main contributor to the resistance offered by the damper. The hydraulic force acting on the PCV significantly impacts the overall performance of SAHD. To quantify the reaction force of the valve before and after optimization under different valve displacements and hydraulic pressures were simulated
Chintala, Paramesh, Hornby, Ryan
Effects of Jet Caps on Hydrogen Piezoelectric Injectors for DI Applications: Experiments and 3D-CFD Simulations2025-01-84544/1/2025
The adoption of hydrogen as a sustainable replacement for fossil fuels is pushing the development of internal combustion engines (ICEs) to overcome the technical limitations related to its usage. Focusing on the fuel injector in a DI configuration, it must guarantee several targets such as the adequate delivery of hydrogen mass for the given operating condition and the proper mixture formation in the combustion chamber playing a primary role in reaching the target performance in H2-ICEs. Experimental campaigns and computational fluid dynamics simulations can be used as complementary tools to provide a deep understanding of the injector behaviour and to drive design modifications in a quick and effective way. In the present work an outward opening, piezo-actuated injector purposely designed to be fuelled with hydrogen is tested on several operating conditions to evaluate its performance in terms of delivered mass flow and jet morphology using the Schlieren imaging technique. To
Pavan, Nicolò, Cicalese, Giuseppe, Gestri, Luca, Fontanesi, Stefano, Breda, Sebastiano, Mechi, Marco, Vongher, Sara, Postrioti, Lucio, Buitoni, Giacomo, Martino, Manuel
Intebrake 3-D CFD Transient Simulation Studies for Predicting Flow Performance2025-01-83624/1/2025
This paper presents transient, complex, moving mesh, 3-D CFD analysis of an intebrake lubrication oil circuit for predicting flow performance. Intebrake is a mechanism for improving braking performance during over speeding conditions. The mechanism briefly opens the exhaust valve at the end of a compression stroke with a small valve lift and releases the compressed gases, thereby helping in quick application of the brake. There is no fueling during the process and hence, no combustion induced pressure rise which helps in quick application of the brake. During the intebrake operation, opening of the exhaust valve is achieved by using a complex lube oil circuit inside the exhaust rocker lever. The intebrake lube oil circuit consists of various spring-operated valves with micro-sized clearances, high oil pressure generation up to ~ 250 bar, 3-D movement of the mechanism components, and it is a transient operation. The 3-D movement consists of simultaneous rotational and translational
Tawar, Ranjit Ramchandra, Pasunurthi, Shyam Sundar, Bedekar, Sanjeev, Ranganathan, Raj
Supervisory Control System Development for a Toyota Mirai FCEV2025-01-85864/1/2025
The performance of a second-generation Toyota Mirai fuel cell was characterized as part of the SwRI internal research program. This data was used to develop a supervisory controller scheme designed to balance the plant for the fuel cell system during steady-state and transient vehicle conditions. This was accomplished using a Supervisory Integrated Controller (SIC) implemented on a Real-time Power Electronics Control System (RPECS) with a Simulink-based control algorithm. The actuators of interest are the three hydrogen injectors at anode inlet, air compressor and three air side valves on at the cathode inlet. The FC power measurement and pressure sensor readings at the anode and cathode were utilized as real-time feedback for the controller operation. The aim of the controller was to achieve and maintain the power target set by the hybrid powertrain ECU present on the vehicle, which is responsible for balancing power on the fuel cell and battery over the high-voltage bus. These
Chundru, Venkata Rajesh, Kubesh, Matthew, Legala, Adithya
Biomimetic Speaking Valve Increases Safety of Tracheostomized PatientsTBMG-526273/1/2025
University of Freiburg, Freiburg, Germany
Research of Pressure Control Based on Dither2025-01-70401/31/2025
The purpose of the paper is to study the impact of dither on how to improve the pressure control capability in common rail system. The dither is directly operating to the inlet metering valve and making the metering flow accuracy. The correlation between rail pressure and metering flow was analyzed. Optimizing the inlet metering valve control is to improve the pressure control. To overcome the hysteresis problem of the inlet metering valve and improve its stability and rapidity on the pressure control. The PID control strategy based on the pressure control were applied in the common rail system and many papers have introduced the logical. But the dither application was seldom introduced in the common rail system. The dither was specified for the inlet metering valve. With the proper dither signal, the stick-slip motion of the metering valve spool converted to a steady one and the dynamic performance was optimized. To verify the theoretical and calibrated the proper dither signal, the
Kuang, Pengda, Chen, Huiqing, Zhang, Jing, Ran, Ye
Multi-Criteria Evaluation and Operating Parameter Optimization of the SOFC-GT System under Variable Loads2025-01-70771/31/2025
At present, due to the complexity and nonlinearity, the thermal safety and economic feasibility assessment and optimization of the Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) system under variable loads is important to extend the service life and reduce the cost. To solve these problems, this paper proposes a top-level cyclic SOFC-GT system, which considers the design of two-stage preheaters, as well as the impact of material reaction kinetics and thermoelectric coupling characteristics on system performance. Furthermore, the multi-criteria evaluation of the SOFC-GT system under variable loads has been studied, with evaluation indicators primarily including thermodynamic and economic indicators. Afterwards, a Spearman-based parametric sensitivity analysis is used to explore the response trends of performance indicators within the SOFC-GT system. Additionally, an intelligent learning method based on convolutional neural network is designed to determine the dynamic behavior between
Fan, Liyun, Kui, Xu, Chen, Chen, Shen, Chongchong, Li, Bo, Wei, Yunpeng
Pressure-Dependent Nonlinearities of a Compact Hydropneumatic Strut with Integrated Gas–Oil Chamber10-09-01-00081/24/2025
Hydropneumatic Struts (HPS) are widely implemented in automobile, aerospace, and construction industries, mainly for the purpose of vibration and shock absorption. The HPS design with integrated gas–oil chamber is relatively more compact and robust, while mixing gas and oil inside the HPS generates gas–oil emulsion and more nonlinearities. This study formulated a nonlinear analytical model of the compact HPS with gas–oil emulsion, considering the real gas law and pressure-dependent LuGre friction model. The polytropic version of the van der Waals (vdW) method for real gas is applied to represent the thermodynamic behavior of nitrogen. The experimental data were collected at a near temperature of 30°C with three charging pressures under excitations in the frequency range of 0.5–6 Hz, considering two flow connection configurations between chambers as one- and two-bleed orifice. The nonlinear behavior of the gas volume fraction of the emulsion was identified based on peak strut velocity
Seifi, Abolfazl, Yao, Yumeng, Yin, Yuming, Moore, Masih, Rakheja, Subhash
Ball Valve Assembly Yields Linear Flowrate ControlTBMG-5219012/1/2024
Innovators at NASA Johnson Space Center have developed an adjustable thermal control ball valve (TCBV) assembly which utilizes a unique geometric ball valve design to facilitate precise thermal control within a spacesuit. The technology meters the coolant flow going to the cooling and ventilation garment, worn by an astronaut in the next generation space suit, that expels waste heat during extra vehicular activities (EVAs) or spacewalks.
Synergistic 1-D and 3-D Analysis to Optimize the Performance and Reliability of the Reed Valve Used in Reciprocating E-Compressor2024-28-001310/17/2024
With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed. Since it is the order of milliseconds, the valve
J, Bharadwaj, T, Sukumar, Pendyala, Vamsi Krishna, Paul Pandian, Adheenthran
Crewmember Demand Oxygen Mask for Transport Category AircraftAS8026B (Current)9/13/2024
This standard covers oxygen masks and breathing valves used with both panel mounted and mask mounted demand and pressure-demand oxygen regulators. Mask mounted oxygen regulators are covered under other standards, but when the mask mounted regulator incorporates an integral exhalation valve, the performance of this valve shall meet the requirements of this standard.
A-10 Aircraft Oxygen Equipment Committee
PRODUCT BRIEFS24AUTP08_138/1/2024
Optimization of the Overall Heat Transfer Coefficient of the Frozen Seal Valve Fin Tube Assembly for Fast Reactors05-17-04-00236/27/2024
Sodium is used as a coolant in the fast reactor’s primary and secondary loops to transfer enthalpy from the reactor and transport it to the expander. However, handling sodium is difficult, and it can be hazardous if it comes into contact with air, which causes an exothermic reaction. During maintenance of sodium loop components, isolation is typically accomplished with valves. The valve leaking is caused by the seal or the gland. Seal leakage is compensated because it occurs within the line, but gland leakage should be zero because the liquid is harmful. To address this requirement, the author attempted to design a special type of valve in which sodium is allowed to rise through an annular path along the stem and heat transfer is augmented in such a way that the required enthalpy is evacuated to freeze sodium inside the annular path, confirming the fail-safe zero gland leakage. A finned tube assembly is fitted around the stem to achieve this concept of expanded surface heat transfer
Kudiyarasan, Swamynathan, Biswas , Sitangshu Sekhar
PRODUCT BRIEFS24AUTP06_136/1/2024
Control Valves: Essential Components for EV Battery Manufacturing and RecyclingTBMG-508196/1/2024
Application of MAN Loop Scavenging in a 125 cc Two-Stroke Racing EngineSAE-PP-003955/8/2024
The use of MAN-type loop scavenging port arrangements in a 125 cc two-stroke racing engi-ne is being investigated. These make it possible to provide larger cross-sections for the trans-fer ports, but at the expense of the exhaust port cross-section. The investigation is carried out using 1D calculations with GT-Suite. It is shown that significantly higher maximum outputs are possible in this way. However, this requires large exhaust widths, as otherwise the exhaust port is too small and the advantage of the larger transfer cross-section is overcompensated. Mixed forms between the original MAN loop scavenging and Schnürle loop scavenging can represent a good compromise. One open point is the quality of the scavenging. A study found in the literature on the use of MAN loop scavenging on a small engine shows significantly worse results than is known from large engines. There is still a need for further investigation here.
Eilts, Peter
Application of Large Eddy simulation to Gasoline Engine and Comparison against RANS2024-01-24194/9/2024
The work presented is a comparative analysis between Reynold’s Averaged Navier Stokes (RANS) and Large Eddy simulation (LES) description of turbulence to capture the in-cylinder flow structures. Simulations are performed using RNG k - € RANS model and LES one equation eddy viscosity model with Werner and Wengle wall model. ECFM combustion model has been used to achieve the desired rate of heat release when compared against the experiments. KH-RT spray model has been used to define the primary and secondary breakup of parcels. A Renault engine operating on Miller cycle has been chosen for this study. Consecutive perturbation method (CPM) available in Converge has been used to take the advantage of availability of higher number of cores to reduce the effective CPU time. Results of RANS simulation indicates that increase in valve overlap results in faster tumble decay compared to LES. Moreover, it is also found that LES required lesser tuning of flame stretch due to turbulence and a
V G, Srujan, Servant, Cedric, Rathinam, Balamurugan
Implementation of a Driver-in-the-Loop Methodology for Virtual Development of Semi-Active Dampers2024-01-27594/9/2024
In today’s rapidly evolving automotive world, reduction of time to market has prime importance for a new product development. It is critical to have significant front-loading of the development activities to reduce development time while achieving best in class performance targets. Driver-in-the-loop (DIL) simulators have shown significant potential for achieving it, through real time subjective feedback at preliminary stages of the vehicle development. Recent advances in technology of driving simulators have enabled quite accurate representation steering and handling performance, also good prediction on primary ride and low frequency vibrations. In conventional damper development, the definition of the initial dampers tuning specifications typically requires a mule vehicle, or atleast, a comparable vehicle. However, this approach is associated with protracted iterations that consume substantial time and cost. This becomes even more critical when introducing new damper technology on
Rasal, Shraddhesh, Asthana, Shivam, Vellandi, Vikraman, Arconada, Verónica Santos, Tosolin, Guido
Joining of Titanium and Stainless-Steel Rods with an Interlayer Using an Eco-Friendly Welding Process for Automobile Applications2023-01-51262/23/2024
Solid rods of dissimilar metals are easily welded by friction welding. This process is a solid-state process where no fumes or gases are released which is friendly to the environment. In advanced engineering practice, joining Titanium (Ti) alloy and stainless steel (SS) is very important due to poor bonding strength in direct joining. These materials are easily joined by an interlayer technique using materials like nickel, silver, niobium, aluminum, and copper. Special surface geometry techniques hold the interlayer materials between dissimilar metals in different forms like coating, foils, and solid metals. In this investigation, the finite element method is used for modeling the process, and the Johnson-cook equation was used to find the analysis of output values with the defined material properties. The heat generated is calculated and numerically compared and analyzed with experimental results. Observations such as metallography, hardness, and tensile test were studied. The results
Balasubramanian, M., Prathap, P., Madhu, S.
The Use of Parylene-Coated Mandrels in the Balloon Catheter Manufacturing ProcessTBMG-499812/1/2024
The process of manufacturing high-quality and reliable balloon catheters is critical to a number of advanced medical treatments for patients including balloon angioplasty, stent and drug delivery, transcatheter aortic valve implantation, atherectomy, renal denervation, and laser balloon angioplasty. These minimally invasive procedures have vastly improved quality of life, increased patient safety, decreased recovery times, and lowered treatment costs for patients around the globe.
Optimal Operation of Purge Valve to Reduce the H 2 Wastage in the Fuel Cell2024-26-01661/16/2024
A Proton Exchange Membrane Fuel Cell requires the input of Oxygen from the Cathode and Hydrogen from the anode. As atmospheric air is fed into the system for power generation, nitrogen molecules enter the fuel cell along with oxygen molecules. Over time, an accumulation of nitrogen inside the fuel cell leads to an increase in the effective impedance, which in turn leads to an increase in losses inside the fuel cell, hence reducing the fuel cell efficiency. To reduce the losses, most of the PEM fuel cells have a purge valve at the anode. This purge valve is operated frequently as the impedance increases to let out the nitrogen molecules. During the purging operation, some amount of Hydrogen is let out along with nitrogen, which cannot be recovered. In other words, loss of Hydrogen could also be considered in terms of reduction in system efficiency. Conventionally, nitrogen purging operation in fuel cell takes place reactively as voltage/ power drop across the electrode increases above a
Shah, Saurabh, Bhat, Adithya, Munirajappa, Chandrashekara, Prasad P, Shilpa, Choubey, Ayush
Maximizing Flexibility in Distributed I/O and Valve SystemsTBMG-4959012/1/2023
Manufacturers of automation components have long made pneumatic valve terminals with IP65 and IP67 ratings that can be mounted anywhere on a machine. This is particularly useful for connecting valves as close to pneumatic actuators as possible. Doing so shortens the length of tubing, reduces the occurrence and severity of leaks, and increases actuator performance by shortening cycle times. Decentralized valve terminals communicate with the machine controller or PLC via an industrial Ethernet network. In addition to valves, terminals are configured with input and output modules to allow for easy connection of sensors, switches, and other field-level devices to the industrial network.
Study the Effect of Pneumatic Valve Characteristics due to Linear and Non-Linear Damping System2023-28-016011/10/2023
Pneumatic valves are widely used in heavy commercial vehicles’ air braking systems. These valves are mainly used in the braking system layout to maintain the vehicle stability during dynamic conditions. Rubber components are inevitable in valves as a sealing element, and it is very difficult to predict the behavior due to its nonlinear nature. Basically, this valve efficiency is defined in terms of performance and response characteristics. These characteristics are determined in the concept stage itself using 1D simulation software. AMESim software has a variety of elements to use in a unique way for performance and response behavior prediction. For pneumatic valves, 1D analysis is an effective method and it gives good correlation with actual test results. During the modelling of pneumatic valves, some of the contacts between rubber and metals are controlled by various parameters such as damping, contact stiffness and desired phase angle. Instead of giving these parameters to a linear
Kandasamy, Sugumar, T, Sukumar, Pendyala, Vamsi Krishna, Govindarasu, Anbarasu
Experimental Comparison of a Rotary Valvetrain on the Performance and Emissions of a Light Duty Spark Ignition Engine2023-01-161310/31/2023
Rotary valve technology can provide increased flow area and higher discharge coefficients than conventional poppet valves for internal combustion engines. This increase in intake charging efficiency can improve the power density of four-stroke internal combustion engines, particularly at high engine speeds, where flow is choked through conventional poppet valves. In this work, the valvetrain of a light duty single cylinder spark ignition engine was replaced with a rotary valve train. The impact of this valvetrain conversion on performance and emissions was evaluated by comparing spark timing sweeps with lambda ranging from 0.8 to 1.1 at wide open throttle. The results indicated that the rotary valvetrain increased the amount of air trapped at intake valve closing and resulted in a significantly faster burn duration than the conventional valvetrain. Additionally, the spark to CA10 burn duration of the rotary valvetrain was highly sensitive to spark timing, which was not true of the
Gainey, Brian, Vaseleniuck, Darrick, Cordier, Dan, Garrett, Norman
Performance Prediction of an e-Compressor Using 3D CFD Simulation2023-28-00159/14/2023
Scroll compressors are commonly used in HVAC and thermal management systems of electric and hybrid vehicles because of its high operating efficiency and smooth operation. The compressor is driven by an electric motor which forms a coupled system called an e-compressor unit. The refrigerant cools the motor before entering the scroll compressor. At different operating conditions of the vehicle, the change in power of the motor alters the refrigerant temperature and hence affecting the compressor’s performance. In the present work, 3D Conjugate Heat Transfer simulation of an e-compressor is performed as a complete unit with flow and heat transfer through the motor and compressor. A novel mixed timescale approach for the heat transfer has been developed to simulate the effect of thermal loads on the performance of the compressor. These performance parameters include the outlet temperature, volumetric efficiency, and discharge flow rate of the compressor. The motion of reed valve at the
Ballani, Abhishek, Pasunurthi, Shyam Sundar, Srinivasan, Chiranth, Maiti, Dipak
High Performance and Near Zero Emissions 2-Stroke H 2 Engine2023-24-00688/28/2023
The paper presents a preliminary study on a virtual 2-stroke 3-cylinder 0.9 L DI SI supercharged engine running on Hydrogen (H2), able to meet both high performance targets and ultra-low emissions limits (NOx<20 ppm). Combustion is similar to a conventional 4-stroke H2 DI engine, while the design of the cylinder and the actuation law of both intake and exhaust valves are specifically optimized for the 2-stroke cycle. In comparison to a more conventional 2-stroke loop scavenged engine, with piston-controlled ports, the use of poppet valves enables a more flexible control of the gas exchange process and to maintain the same design of a 4-stroke engine for pistons, cylinders block, crankcase and lubrication system. On the other hand, it is more difficult to avoid the short-circuit of the fresh charge, while permeability of the valves becomes quite critical at high engine speed. Therefore, particular care was devoted to the optimization of the intake and exhaust ports geometry, as well as
Caprioli, Stefano, Volza, Antonello, Mattarelli, Enrico, Rinaldini, Carlo Alberto
Air Dryer Installation ProcedureJ2383_202305 (Current)5/24/2023
This SAE Recommended Practice establishes uniform Installation Parameters for desiccant Air Dryers for vehicles with compressed air systems.
Truck and Bus Brake Supply and Control Components Committee
Pressure Testing, Gaseous Media Pressure as SpecifiedAMS2610 (Current)5/24/2023
This specification provides requirements and procedures for gas-pressure leak testing of parts.
AMS B Finishes Processes and Fluids Committee
Minimum Standards for Valve, High Pressure Oxygen, Cylinder Shut Off, Manually OperatedAS1066B (Historical)4/26/2023
This standard covers all types of manually operated high pressure oxygen, cylinder shut off valves for use in commercial aircraft. It is intended that the valve shall be attached to a pressure cylinder storing oxygen under a nominal pressure of 12.76 MPa (1850 psig) at 21 °C (70 °F). Upon opening the valve, oxygen will be permitted to discharge from the storage cylinder to the valve outlet and to other downstream components of the oxygen system. It shall also be possible to recharge the cylinder through the valve.
A-10 Aircraft Oxygen Equipment Committee
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