Browse Topic: Thermal testing

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Characterization of a Low-Cost Insulator Substrate for Traction Power Modules2026-01-01194/7/2026
Demand for cost-effective automotive traction inverters requires improved power module packaging. This paper presents a packaging method using an epoxy composite insulator applied directly to the cold plate surface, replacing Direct Bonded Copper (DBC) and Active Metal Brazed (AMB) substrates. This integration removes the substrate-to-cold plate solder interface and eliminates two material layers from the thermal path. The epoxy composite demonstrates a dielectric strength greater than 60 kV/mm. Thermal resistance (junction-to-coolant) measured approximately 0.17 K∙cm2/W. Electrical characterization showed a relative permittivity of 3.9, which is lower than standard ceramics and results in reduced parasitic capacitance. Initial thermal cycling tests indicated no significant degradation in thermal or electrical performance. These results suggest the epoxy composite insulator could be a promising alternative for traction power modules.
Chen, Yu, Mena-Garcia, Javier, Chen, Hao, Xiao, Kewei, Gupta, Man Prakash, Degner, Michael
Derating as Thermal Protection for LED-Based Lighting Applications2025-01-506610/3/2025
This paper investigates the concept of derating in light-emitting diode (LED)–based automotive lighting systems, emphasizing its role in enhancing LED longevity, performance, and reliability under varying operating conditions. Derating is introduced from a general perspective and is modeled as an approximately linear function of the driving current with respect to the temperature measured by a negative temperature coefficient thermistor (NTC). The NTC serves as a temperature probe in this context. We demonstrate that poorly designed derating strategies can negatively impact luminous flux, lifespan, and overall system reliability. These theoretical insights are applied to a simplified lighting system, which is analyzed using both steady-state and transient computational fluid dynamics (CFD) simulations to illustrate the practical effects. It is shown that the distance between the NTC and the temperature-critical region primarily determines the slope of the derating curve, while having minimal influence on thermal protection on dynamic response. Finally, the precision of NTC-based temperature measurements defined by the thermistor specifications is briefly examined. It has an additional influence on the accuracy if the applied derating.
Stahlbaum, Ruben
Analysis of Front Axle Wheel End Temperature Measurements in Heavy-Duty Trucks2025-01-03649/15/2025
The Front Axle wheel end assembly is a critical component of Vehicle functionality, comprising a wheel hub positioned to rotate smoothly on an Axle spindle. This rotational movement is enabled by bearings positioned between the hub and the spindle, allowing for frictionless rotation. The Front Axle wheel ends’ temperature typically depends on several factors such as type of Vehicle, Load & driving conditions and health of the components involved. In general, the wheel ends can become warm during normal operation owing to friction generated by the rotation of the wheels and the interaction of various mechanical components such as Bearings and Brakes. However, if the temperature of the wheel ends becomes excessively hot, it could indicate potential issues such as Overheating brakes, Wheel bearing problems, improperly inflated tyres, and faulty components. As temperature rise, materials tend to expand. This expansion can affect the dimensions of critical components in the Front Axle wheel end, potentially leading to misalignment or increased friction between moving parts. Hence, it is very important to check the temperatures at various operating conditions and ensure to limit it within acceptance level to detect problems early on and prior to the Customer Vehicle operation. This paper emphasizes on the comparative test results of the Wheel ends’ temperature between Conventional and Unitized Bearings and its physical measurements carried out in a same Vehicle. Conventional bearings, which typically consist of separate Inner and Outer bearing assemblies, might exhibit higher operating temperatures compared to Unitized bearings owing to additional friction points and potential for misalignment. Unitized bearings, which integrate multiple components into a single assembly, tend to operate at lower temperatures compared to conventional bearings due to reduced friction and improved alignment. The Vehicle level temperature measurements at various worst-case conditions carried out and proved that the measured values are in correlation with estimated results. Maintaining appropriate temperatures in the Front Axle wheel ends is crucial for ensuring optimal performance of the Vehicle’s Braking system and drivetrain.
Pandiyan, Mahendran, Jayaraman, Karthik, R, Sabari, B, Ellavarasan, Bhanja, Subrat Kumar
Application of Sustainable Aviation Fuels in Compression Ignition Aviation Engines: In-Flight Investigations2025-01-03177/2/2025
To achieve a significant reduction in net CO₂ emissions in the aviation sector, sustainable aviation fuels (SAFs) are considered a key factor. Current research efforts are therefore focused on SAFs, which exhibit properties that differ from conventional kerosene, particularly in aspects critical to compression-ignition (CI) engines, such as cetane number, evaporation behavior or lubricity. These differences necessitate dedicated investigations to assess their suitability and performance in such engines. However, real operating conditions — such as intake air- and exhaust- pressure levels during flight — cannot be fully replicated on standard engine test benches. For this reason, real flight experiments were conducted to address these limitations. Notably, this work marks the first instance of in-flight testing of SAFs in CI aviation engines, constituting a significant milestone in this research area. In the course of these investigations, ASTM D7566 Annex A2-compliant HEFA (hydroprocessed esters and fatty acids) was tested across a wide range of blend ratios, including pure HEFA. The in-flight tests were performed, using a DA42 aircraft from Diamond Aircraft Industries (DAI), equipped with two AE330 engines from Austro Engine (AE). For safety reasons, one engine was left in its original configuration, while the other one was outfitted with advanced measurement systems, including in-cylinder pressure sensors, a mobile exhaust gas analysis system (portable emission measurement system - PEMS), and various pressure and temperature probes. This setup enabled precise measurement of gaseous emissions, particle number (PN), efficiency, and combustion parameters. The operation of the test engine with HEFA blends, up to and including pure HEFA, was successfully demonstrated. The flight campaign highlighted the emission potential of this aromatics-free fuel. Additional test bench investigations confirmed the findings from the initial flight campaign: while soot mass emission decreased significantly with increased HEFA-share, particle number (PN) remains on a constant level, indicating a shift in the particle size distribution. This emphasizes the importance of understanding the trade-offs and adapting engine calibration when using SAF in CI (aviation) engines.
Kleissner, Florian, Reitmayr, Christian, Hofmann, Peter
The Guangzhou Automotive Group Co. Aerodynamic, Acoustic, and Thermal Wind Tunnel2025-01-87884/1/2025
The Guangzhou Automotive Group Co., Ltd (GAC Group) wind tunnel, located in Guangzhou, China, is a state-of-the-art facility that uniquely integrates world-class aerodynamic flow quality, acoustic capability, and thermal conditions into a single system for the development of passenger vehicles. This closed return, ¾ open jet wind tunnel features a nozzle with a cross-section of 20 m2 and a 2.5 MW fan, capable of delivering a maximum wind speed of 200 km/h. The wind tunnel is equipped with a ±90° turntable, a boundary layer control system, and a 5-belt moving ground plane system for aerodynamic tests. Comprehensive acoustic treatments in the test section and throughout the wind tunnel circuit establish a hemi-anechoic test environment with minimal background noise levels for acoustic tests. For thermal tests, the wind tunnel includes a 4-wheel chassis dynamometer system downstream of the turntable, with temperature control ranging from 20°C to 60°C and humidity control between 15% and 90% with the maximum dew point of 36°C. The facility is also equipped with a solar simulation system. The boundary layer control system includes a specific system to improve the aerodynamic condition at the dynamometer location during thermal testing. The key instrumentation comprises systems for measuring wind speed, temperature, and humidity, a 6-component force balance built into the turntable, and a flow survey traverse system equipped with a 3-D probe holder mechanism, enabling probe placement anywhere within the test volume. This paper introduces the GAC wind tunnel testing capabilities and design features, presenting results from the aero-acoustic commissioning program. The aerodynamic and acoustic performance results are compared with those of other automotive facilities worldwide.
Bender, Trevor, Nasr Esfahani, Vahid, Liu, Zheng, Yang, Hui, Li, Shuya, Song, Xin, Liu, Man, Ma, Zhijian
3D-Printed Engines Propel Next Industrial RevolutionTBMG-5197611/5/2024
In the fall of 2023, NASA hot fire tested an aluminum-based, 3D-printed rocket engine nozzle. What made the event remarkable is that aluminum isn’t typically used for additive manufacturing because the process causes it to crack, and it isn’t used in rocket engines due to its low melting point. Yet the test was a success.
Thermal Analysis of Components and Traces on Printed Circuit Boards2024-26-02791/16/2024
High currents flowing through various traces of a printed circuit boards (PCB) causes thermal run away and PCB warpage due to the occurrence of high heat density. The present study discusses on steady state thermal analysis performed in a PCB kept inside an enclosure. Thermal analysis allows PCB designer to quickly move and confirm the component’s placement by examining the temperature plots predicted on the PCB surface. A PCB particularly designed for automated manual transmission (AMT) application employed in Ashok Leyland electric vehicle (EV) trucks is used for this present study. The performed simulations are preliminary level and carried out with commercially available software Altair Simlab ElectroFlo 2022.3. Simlab is a PCB level EDA (Electronic Design Automation) software suite used for design and analysis, and thus helps in minimizing the development cycles. The power dissipation for each and every component and the component analysis power level plays a significant role in deciding the temperature at various components in the PCB. The temperature at various locations of the PCB and enclosure is predicted and compared with some benchmark values presently available and measured at the vehicle level. A good agreement is observed between both the predicted and measured values. Here, the objective is to detect these thermal issues at the initial design level itself, so as to improve reliability of the controller.
Rajasekharan, Jayakrishnan, Prasad, Suryanarayana, ML, Sankar. T
Hot Tensile Properties of Shielded Metal Arc Welded Similar and Dissimilar Joint of 9Cr-1Mo Steel and 304 Stainless Steel2024-01-50001/15/2024
The recent demand for power generation capability has raised the operating temperature of the power plants in the range of 600°C. High operating temperature leads to material degradation or reduced lifespan of boilers, which necessitates the analysis of the high-temperature behavior of welded joints of power plant boilers for a long lifespan and improved efficiency. Gr91 martensitic and SS304 austenitic stainless steel are identified as the primary piping material for these boilers. The boiler piping involves similar weld joints (Gr91/Gr91 and SS304/SS304) and dissimilar weld joints (SS304/Gr91) known as transition joints. These joints are exposed to high temperatures for a long duration during their service and it is therefore necessary to evaluate the high-temperature behavior of these weld joints. The hot tensile test is a short-term high-temperature test that serves as a valuable tool for analyzing the high-temperature behavior of the welds. In this investigation, by using the shielded metal arc welding (SMAW) process, similar joints of Gr91/Gr91 martensitic steel, SS304/SS304 were made using matching electrodes, and dissimilar joints between Gr91/SS304 were welded using INCONEL electrode. The joints were subjected to hot tensile test at temperatures of 550°C, 600°C, and 650°C. The stress–strain behavior of the weld joints at elevated temperatures was studied, compared with each other, and reported.
Karthick, K., Balasubramanian, M., Madhu, S., Prathap, P.
Clutch Housing Temperature Prediction during Repeat Restart Test Using Machine Learning2023-01-508712/19/2023
Product validation time reduction and limit number of physical testing is major challenge all over the world OEMs are facing and they are trying to use latest technologies to fill gap between design parameters, simulated results, and physical validation results. Automotive industry is going through a major transformation with use of artificial intelligence and machine learning and especially in the area of transmission system design and development where lot of data is available from physical testing. Clutch is still being used in internal combustion engines vehicles. Clutch is an important part in transmission system in vehicle, which transmits power generated from engine to transmission and changes the gears at different speed. Design and validation of clutch is a critical and laborious task. Clutch failure occurs due to excessive rise in temperature. The motivation behind this work is to reduce clutch design and selection cycle time and iteration, since physical testing and CAE iteration are a time consuming and costly process for any automotive OEMs. Physical testing requires manpower and test setup. If clutch design engineer knows temperature inside clutch housing before design finalization then corrective actions can be taken to avoid failures during field trials by providing early feedback from results predicted by machine learning model. This paper focuses on prediction of clutch housing temperature during physical validation of a clutch using machine learning. Historical data of different vehicles is used for development of machine learning model. The current study focuses on the machine learning approach for prediction of clutch housing temperature. The machine learning methodology and results correlation between machine learning predicted results and physical test results for different types of commercial vehicles. The developed solution using machine learning helps clutch design engineer in selection of critical clutch parameters so that clutch design can be improved at early vehicle design stage.
Kulkarni, Prasad Ramesh, Sahu, Dilip
Scan Sequence Optimization for Reduced Residual Stress and Distortion in LPBF Additive Manufacturing – An AISI 316L Case Study2024-01-40518/10/2023
ABSTRACT Laser powder bed fusion (LPBF) additive manufacturing often results in defective parts due to non-uniform temperature distribution during fabrication. To mitigate this issue, the authors recently introduced SmartScan, an intelligent method that employs modeling and optimization to generate scan sequences that improve temperature uniformity. However, the previous version of SmartScan could only be applied to single layers. This paper presents an extension of SmartScan to three-dimensional parts by adjusting the thermal model and optimization objective. Through simulations and experiments involving fabricating AISI 316L stainless steel parts, the study demonstrates that the proposed SmartScan approach significantly improves temperature uniformity, reduces part distortion, and mitigates residual stress, as compared to conventional heuristic sequences. Citation: C. He, C. E. Okwudire, “Scan Sequence Optimization for Reduced Residual Stress and Distortion in PBF Additive Manufacturing – An AISI 316L Case Study,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 15-17, 2023.
He, Chuan, Okwudire, Chinedum E.
Methodologies and Equipment for Measuring High Temperature Tensile Properties of Subscale Specimen Geometries for Additively Manufactured Metallic Materials (Continued)23AERP08_108/1/2023
Editorial Note: With the growth in adoption of addititively manufactured materials across aerospace and defense manufacturing, we decided to include two parts of this Air Force Research Lab report. Air Force Research Laboratory, Wright-Patterson Air Force Base, OH Universal test frames are generally either screw-driven or servohydraulic, which are both perfectly suited for uniaxial tensile testing experiments. A uniaxial test frame is comprised of several basic fixture components: loading device, a load cell, and a specimen gripping apparatus. An example of a commercially available tensile testing frame is shown below. Load cells are available in a wide range of load limits to accommodate the sensitivity needs for a wide range of materials and specimen geometries. ASTM E74 outlines the calibration procedure for load cells and must be followed to ensure proper measurement during testing, regardless of specimen size. Further details about alignment and gripping will be provided given their overall importance to testing accuracy. Standardized testing procedures have been established to assist in test frame and specimen alignment through the quantification of bending strains and their acceptable limits during testing.
Relative Thermal Life and Temperature Index for Insulated Electric WireAS4851A (Current)7/24/2023
This test method provides performance data on candidate insulation systems as a function of time and temperature. These data give engineering information on the wire insulation candidate relative to the performance of materials already in use with a backlog of experience. These tests expose candidate insulation systems to a wide range of temperatures for short and long periods of time, while measuring the degradation of its physical properties. For aerospace use, end-point proof tests include mandrel bend, water soak, and dielectric integrity.
AE-8D Wire and Cable Committee
Precise Electrical Machine Stator Winding Modeling for Thermal Analysis of Efficient Cooling Concepts14-13-02-00087/12/2023
The current development of electric and hybrid electric vehicles has drawn more attention toward the development of electrical machines with high power densities. Though highly efficient, these machines heat up significantly during operation. By design, state-of-the-art water jacket cooling concepts remove the heat mainly through high internal thermal resistances of the electrical machine. The resulting maximum temperatures in the end winding region limit the achievable machine power output. In this study, alternative cooling concepts are presented, which efficiently use the existing heat conduction paths of an electric machine. For this purpose, two modeling methods for the stator windings were developed: a high-resolution approach that considers each individual wire and an abstract approach that uses zones of constant anisotropic thermal conductivity to specify the heat flow in the windings. Both models were used in conjugate heat transfer simulations of a long-term thermal test of the electrical machine integrated in the BMW i3. For both models the validation showed a very good agreement of simulated and measured temperatures. An evaluation of both methods showed the abstract approach to be more efficient than other simulation methods used in the current R&D. Its application for alternative cooling concepts revealed the necessary heat transfer coefficients at different fluid temperatures for a sole convective cooling of the end windings. However, it could be found that a homogeneous temperature distribution in the stator of the machine can only be achieved if a combination of water jacket cooling and convective end winding cooling is used.
Brossardt, Nicolas, Nguyen-Xuan, Thinh, Pfitzner, Michael
Standard Method for Determining Continuous Upper Temperature Limit of ElastomersJ2236_202306 (Current)6/27/2023
This method is intended to define the continuous upper temperature limit (CUTL) of thermoplastic elastomers and thermoset rubber with durometer hardness <=90 Shore A, to oxidation or other degradation when exposed solely to hot air for an extended period of time.
Committee on Automotive Rubber Specs
Novel Framework for the Robust Optimization of the Heat Flux Distribution for an Electro-Thermal Ice Protection System and Airfoil Performance Analysis2023-01-13926/15/2023
We present a framework for the robust optimization of the heat flux distribution for an anti-ice electro-thermal ice protection system (AI-ETIPS) and iced airfoil performance analysis under uncertain conditions. The considered uncertainty regards a lack of knowledge concerning the characteristics of the cloud i.e. the liquid water content and the median volume diameter of water droplets, and the accuracy of measuring devices i.e., the static temperature probe, uncertain parameters are modeled as uniform random variables. A forward uncertainty propagation analysis is carried out using a Monte Carlo approach. The optimization framework relies on a gradient-free algorithm (Mesh Adaptive Direct Search) and three different problem formulations are considered in this work. Two bi-objective deterministic optimizations aim to minimize power consumption and either minimize ice formations or the iced airfoil drag coefficient. A robust optimization formulation was also considered aiming to maximize the statistical frequency of the fully evaporative operating regime for fixed power consumption. The framework is applied to a reference test case, revealing the potential to improve the evaporation efficiency of the baseline design, increasing flight safety even at non-nominal conditions. We also conducted a preliminary examination of the impact of run-back ice formations on airfoil performance during a brief ice encounter in uncertain cloud conditions to understand how the rate of ice accretion relates to an airfoil performance metric, such as the drag coefficient. The analysis found that reducing the rate of ice build-up may not necessarily diminish the detrimental effects on aerodynamic performance, except when the rate is very low. Further studies are ongoing to explore airfoil performance degradation in more detail and to reduce the optimization framework computational cost.
Gallia, Mariachiara, Guardone, Alberto, Congedo, Pietro Marco
Design of Dump Truck Body Oscillation Arresting Structure and Material Selection for Sub-Zero Application2023-28-13155/25/2023
The dump body of the off-highway dump truck is the large, prime structure, used to carry overburden and coal in mines. The body structure is subject to severe vibration, impact load, and oscillation events due to rough terrain conditions in the mines and the loading of rocks from a certain height from the shovel. Presently, the body mounting design is chassis pivot pin mounted, rubber rail seated, and has guide plates to lock transverse movements. Despite all these mounting arrangements, the body structure oscillates (or rattles) due to multiple field factors. The most effective solution to the problem is to provide an additional oscillation-arresting structure so that body stability is achieved and undesirable body-frame impact is avoided. The prime objectives of this study are to design an additional oscillation-arresting structure and to select an appropriate material to work at an ambient temperature of -50°C (sub-zero temperature); to carry out the structural behaviour of the existing material (works in normal temperature). The structural design is validated through classical hand calculations and Finite Element Analysis (FEA), qualifying it by Von Misses stress, shear stress, and displacement criteria. Recommending the most suitable material for sub-zero temperature (-50°C) application.
SELVARAJ, SUTHAKAR, Jamadagni, Vishak N.
Modelling of Polymer Suction Tube through Simulations2023-28-13075/25/2023
The oil is picked up from the oil sump and transferred to the pump housing via a suction tube at the desired rate. A strainer is fitted to the end of the suction tube to filter out any dust or debris that may be present. Steel tubes and wire mesh strainers are used to make the current suction tube. Suction tube design shouldn't have an excessively long inlet suction that would make the suction tube's pressure insufficient to suck the oil from sump. Additionally, the pump's suction side air leak or low temperature-induced low oil viscosity prevents the pump from priming. This paper will examine suction tube design analysis and compared the development of steel and polymer suction tube concepts. The lightweight polymer suction tube with respect to fluid dynamics aspects is compared with conventional wire mesh. Extreme temperature analysis of polymer suction tubes will be compared to baseline steel tubes for suction flow, the impact of mesh area, pressure drop, and temperature parameters, and findings will be presented. The flow performance of polymer suction tubes was found to be substantially above that of steel wire mesh suction tubes. Due to the decreased opening area of an all-polymer suction tube, the average pressure drop is larger, and pressure decreases in the suction tube have an impact on the pump's filling speed. Compared to steel suction tubes, polymer suction tubes are lighter and cheaper, easier to manufacture, need fewer parts, and have higher reliability.
NALE, ANIKET ARUN, Maurya, Rohit K, Soma, Nagaraju, Mohammed, Zubair
ARC FAULT CIRCUIT BREAKER - AIRCRAFT, TRIP FREE, 1 TO 20 AMP, TYPE IAS5692/3 (Current)3/27/2023
AE-7P Protective and Control Devices
ARC FAULT CIRCUIT BREAKER - AIRCRAFT, TRIP FREE, 25 TO 35 AMP, TYPE 1AS5692/4 (Current)3/27/2023
AE-7P Protective and Control Devices
Guidelines for the Use and Installation of Large Size Wire/Cable Jacket Damage Repair SleeveARP6824 (Current)10/7/2022
This SAE Aerospace Recommended Practice (ARP) contains guidance to assist users by providing a method to install an AS6224/2 repair sleeve.
AE-8C2 Terminating Devices and Tooling Committee
KEEPING YOUR SILICON COOL22AUTP10_0310/1/2022
A Parker Chomerics expert shares real-world solutions for the heat-dissipation challenges in onboard electronics. Onboard electronics continue to evolve rapidly. Components are smaller. Systems are more complex. The sophisticated electronics components that make up modern vehicles require precision heat dissipation for reliable operation. To help components and systems designers deliver high-performance, cost-effective solutions, the following are several actual cases illustrating the types of thermal interface material (TIM) and their performance properties,
Casper, Scott
Re-imagining Brake Disc Thermal Fatigue Testing to Relate to Field Use2022-01-11639/19/2022
The validation of brake discs has remained, to this day, heavily reliant on “Thermal Abuse” or “Thermal Cracking” type testing, with many procedures so dated that most engineers active in the industry today cannot even recall the origin of the test. These procedures - of which there are many variants - all share the trait of greatly accelerating durability testing by performing repeated high power (high speed and high deceleration) brake applies to drive huge temperature gradients and internal stress, and often allowing the disc to get very hot, to where the strength of the material from which the disc is constructed is significantly degraded. There is little debate about whether these procedures work; by and large disc durability issues in the field are extremely rare. However, without the connection to the duty cycle in the field, it is extremely difficult to interpret results (especially since many standards allow significant cracking before a failure is declared), and this can lead to significant re-testing and design modifications that not necessarily needed. The publication of SAE J2995 (based heavily on VDA 311) provided a versatile and powerful means of relating simple lab-based test duty cycles to severe field use. There is not a straightforward interpretation of J2995 for brake discs; however, in combination with simple models relating braking power to disc stresses, a potential path emerges to connect disc thermal abuse to field use. The present study explores this path, with a series of inertia dynamometer-based studies designed to see if an S-N curve (relating braking power to disc life) could be developed for disc thermal abuse, and if this could then be used to relate the results to customer use. Initial results are promising, giving hope that disc durability validation can transition eventually to a less empirical, and more engineered approach.
Antanaitis, David, Langhart, Jerry
Cab Air-Conditioning Test Procedure - Heavy Trucks with and without SleepersJ2646_202206 (Current)6/20/2022
This SAE Recommended Practice establishes a uniform test procedures for on highway trucks equipped with an air-conditioning system used to condition the air in the cabin and sleeper compartment of the vehicle. This specification will apply to heavy trucks with and without sleeper compartments.
Truck and Bus Windshield Wipers and Climate Control Comm
Engine-Off Cab Heating and Air Conditioning Systems Test Procedure and Performance Requirements - Trucks with and without SleepersJ2918_202206 (Current)6/20/2022
This SAE Recommended Practice establishes uniform test procedures and performance requirements for engine-off heating, ventilation, and air conditioning (HVAC) systems in order to achieve driver thermal comfort in both winter and summer rest periods. This specification will apply to heavy trucks with and without sleeper compartments, including but is not limited to Class 6, 7, and 8 powered vehicles.
Truck and Bus Windshield Wipers and Climate Control Comm
LED Work Lighting DevicesJ2895_202206 (Current)6/13/2022
This SAE Recommended Practice provides general design performance requirements and related test procedures for LED “white” lighting unit assemblies, other than signal and marking devices, used on Earthmoving, Road Building, and Maintenance off-road work machines as defined in SAE J1116. This report is intended to serve as a guide to standard practice and is subject to change to reflect additional experience and technical advances.
OPTC3, Lighting and Sound Committee
Method Measures Temperature Within 3D ObjectsTBMG-457465/1/2022
Engineers have remotely determined the temperature beneath the surface of certain materials using a new technique called depth thermography. The method may be useful in applications where traditional temperature probes won't work, like monitoring semiconductor performance or next-generation nuclear reactors.
Modeling of Silicone Oil Clutch for Analyzing Thermal Performance2022-01-01773/29/2022
The silicone oil clutch is a device that uses the viscous shear force of silicone oil to transmit torque. Due to the difference in the rotational speed of the driving and driven parts, the silicone oil inside the clutch generates much heat, and the silicone oil temperature increases, resulting in a decrease in viscosity. Therefore, excellent thermal performance is necessary for silicone oil clutch to ensure torque transmission ability. This paper proposes a modeling method for analyzing the thermal performance of a silicone oil clutch. Firstly, the temperature measurement test for the silicone oil clutch is carried out by using wireless temperature measurement equipment. The driven speed, silicone oil temperature, and the temperature of different areas of the clutch shell are measured under different driving speeds. Considering the variation of silicone oil viscosity with temperature and the influence of the fan on the surrounding flow field, the CFD thermal simulation model of silicone oil clutch is established. Under the condition that the driving and driven speeds are equal to the test values, the silicone oil temperature and shell temperature under different working conditions are calculated using the established simulation model and compared with the test values. The results show that the error between the calculated results and the test data is kept below 9.4%, and the calculated results are in good agreement with the test results in the relationship between temperature and driving speed and the temperature change trend in different areas of the shell.
Hu, Wenxuan, Wang, Xihui, Wang, Xinling, Shangguan, Wen-Bin
Investigation of Hot Corrosion Behavior on QE22A-Magnesium Silver Alloy through Steaming Method05-15-03-00153/3/2022
The hot corrosion studies for the die-casted magnesium (Mg) silver (Ag) alloys are carried out through the steam heating route. The Magnesium Silver (QE22A) alloy is fixed under the top lid of the pressure cooker (2 liters) and filled with water and 5% salt (NaCl) solution. The specimens are treated with different time intervals (10, 20, and 30 minutes), with the steam temperature maintained at 100°C around the specimen. The results showed an increase in the corrosion rate with the increase in the steaming time. Further, after the specimens have cooled down to room temperature, similar experiments are repeated for the second and third cycles. Here the formation of the oxide layers over the specimen has reduced the corrosion rate. The structural, surface study was carried out through scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS) to know the corrosion behavior on the specimen. From the microstructure, it is noticed that the average grain size increased with the increase in the time intervals. Through SEM images, detailed studies on the crack length and pitting width were carried out. Finally, a comparison of pure and corroded alloys is made and discussed in detail.
Shailesh Rao, A., Sangamesh, M.A., Nayak, Haridas, Latha, B. M., Pallavi, B. K.
Methodology for Evaluation of Thermal Degradation of Friction Materials in Bench Tests2021-36-04222/10/2022
Friction materials for automotive brakes are composites specially designed for attending various requirements, such as stable friction coefficient, low wear rate, high performance, low fade sensibility, thermal diffusivity, stiffness, strength, etc., in wide temperature ranges. For this reason, several raw materials are combined and processed so that all these requirements are met. Among the characterization tests performed for assessing the mechanical behavior of such materials, uniaxial compression, three-point bending, and internal shear tests are typically preferred. However, properties evaluated at ambient temperature and in a freshly manufactured product are only referential, as these properties tend to vary with temperature and after being subjected to the application. In order to evaluate the magnitude of the variation of mechanical properties of friction materials with temperature, different commercial linings applied to bus drum brakes were chosen, and mechanical characterization was performed at ambient temperature, at 250 oC, and after thermal cycles of heating and cooling. Variations were compared to the ones observed in a friction material, which run for 10000 km on field application. It was registered variations in mechanical properties between 1 % and 74 %, depending on the material, temperature, and the test considered, showing that significant changes can be found between a new and used product. When comparing the results of linings subjected to heating and cooling cycles to the ones obtained from used linings, very similar reductions in the properties were obtained. This shows that it is possible to estimate with reasonable accuracy the real degradation that can be expected in field through fast and straightforward laboratory procedures, which can potentially enhance material development and failure analyses. A Finite Element Structural Analysis was performed on a drum brake considering the variations found in mechanical properties, showing the strong influence of thermal degradation on the structural safety of such materials.
Lazzari, Mauricio, Webber, Jaíne, Matté, Daniel, Pereira, Carlos H. S., Antunes, Diego S., Santos, Roger L., Matozo, Luciano T.
Influence of the chemical composition on the generation of cracks in brake discs2021-36-04232/10/2022
Thermoelastic instabilities in the contact of brake friction material cause hotbands and hotspots on the surface of brake disc. These phenomena generate thermal stresses that result in generation of cracks, which limit the lifetime of the discs. In the present work, the influence of the chemical composition of brake discs on the thermoelastic behavior of the system and on the lifetime of the discs was investigated. The experimental evaluation was carried out in an inertial dynamometer using the SAE J3080 standard procedure applied on a brake system. Two discs (namely A and B) with different chemical compositions were subjected to the tests. The brake pad composition was kept fixed. The thermoelastic effects on the inner surface of the disc were observed by contact (thermocouple) and noncontact measurement techniques (thermography), as well as through photographic images of the disc’s surfaces. Disc A showed negligible amount of Nb while disc B exhibited 0.360%. Besides, disc B presented approximately 15% more content of C (Carbon) than disc A. Disc B showed twice the lifespan of disc A. This can be attributed to the smaller thermal gradients observed in disc B, which is in turn related to the higher thermal diffusivity (htd) measured for this rotor. The htd is explained by a greater density of graphite (related to a greater amount of C in the composition), as well as a finer (influenced by Nb) and well-distributed graphite flakes seen in case of disc B.
Flores, Roberto, Ferreira, Ney Francisco, Neiss, Patric Daniel, Barros, Liu Yesukai, Poletto, Jean Carlos, Buneder, Diogo, Lorandi, Natalia Pagnoncelli, Pavlak, Rafael Paini, Fidler, Genesis Guilherme, Lopes, Carlos Henrique Raposo
A New Approach to Describe Thermal Aging of Automotive Catalysts Containing Precious Metal Alloys2021-01-509510/4/2021
Regarding thermal real-world aging of automotive catalysts, no deeply developed model or correlation is yet available. Therefore, a new method is developed. A diesel oxidation catalyst (DOC) is aged in the oven and indicated a systematic crystallite growth. Additionally, catalytic deactivation is only dependent on the crystallite size. The crystallite size acts as an indicator for the precious group metal (PGM) surface. This determines a quantitative correlation between the temperature stress, the crystallite size, and, finally, the catalytic activity for oven-aged samples of a DOC. On the basis of this result, the method for the description of oven aging is worked out. It is a physical model that gets as input parameters the aging temperature and aging time for oven aging. This information can be used to calculate the crystallite growth. Further, the corresponding catalytic activity for all species (NO, CO, HC) can also get calculated. All results are achieved with DOCs containing a platinum (Pt) palladium (Pd) alloy washcoat. An idea for an enhancement for the description of thermal real-world aging is also introduced. The background of the enhanced model is that also crystallite growth by real-world aging and the corresponding catalytic activity could get calculated for every moment in time of a temperature run.
Bahr, Mario, Petasch, Uwe, Heymer, Heike, Matthey, Björn, Michaelis, Alexander, Zikoridse, Gennadi
Standard Test Method for Aerodynamic Acceptance of AMS1424 and AMS1428 Aircraft Deicing/Anti-Icing FluidsAS5900E (Current)8/19/2021
This SAE Aerospace Standard (AS) establishes the aerodynamic flow-off requirements and test procedures for AMS1424 Type I and AMS1428 Type II, III, and IV fluids used to deice and/or anti-ice aircraft. The objective of this standard is to ensure acceptable aerodynamic characteristics of the deicing/anti-icing fluids as they flow off of aircraft lifting and control surfaces during the takeoff ground acceleration and climb. Aerodynamic acceptance of an aircraft ground deicing/anti-icing fluid is based upon the fluid’s boundary layer displacement thickness (BLDT) on a flat plate, measured after experiencing the free stream velocity time history of a representative aircraft takeoff. Acceptability of the fluid is determined by comparing BLDT measurements of the candidate fluid with a datum established from the values of a reference fluid BLDT and the BLDT over the dry (clean) test plate. Testing is carried out in the temperature range at which the fluid, undiluted and diluted, is to be used in airline service.
G-12ADF Aircraft Deicing Fluids
Equivalence of Equipment Environmental Qualification Standards for Civil and Military Aircraft EquipmentAIR6811 (Current)6/22/2021
This document provides guidance for applying aircraft equipment electromagnetic, electrical, and mechanical qualification standards (i.e., DO-160, MIL-STD-461, MIL-STD-704, and MIL-STD-810) to civil aircraft certification intended for military use and for military aircraft equipment installed on civil aircraft. The guidance identifies where the equipment environmental qualification standards meet the intent of both the civil or military aircraft certification requirements. Conversely, the guidance will identify where the equipment environmental qualification standards have differences that do not meet the intent of the civil or military aircraft certification requirements and when these differences matter based on equipment criticality, installation location, and/or other variables.
AE-4 Electromagnetic Compatibility (EMC) Committee
Test Methods and Equipment for Lighting Devices for Use on Vehicles Less than 2032 mm in Overall WidthJ575_202104 (Historical)4/1/2021
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document provides standardized laboratory tests, test methods and equipment, and requirements for lighting devices covered by SAE Recommended Practices and Standards. It is intended for devices used on vehicles less than 2032 mm in width. Tests for vehicles larger than 2032 mm in overall width are covered in SAE J2139. Device specific tests and requirements can be found in applicable SAE technical reports.
Test Methods and Equipment Stds Committee
An Experimental and Numerical Study of Precision Cooling to Determine Optimum Coolant Velocity of Downsized Internal Combustion Engines Using Boiling2021-01-50202/18/2021
Nowadays, due to the internal combustion engine (ICE) industry’s orientation toward downsizing, modern efficient cooling systems with lower power consumption, small size, and high compactness are essential. To improve these items, applying precision cooling and boiling phenomenon are inevitable. Having an appropriate coolant flow velocity that leads to utilize only the advantages of boiling heat transfer has always been a challenge. Two experimental test rigs, one for modeling and accurate prediction of subcooled flow boiling and the other for measurement and validation of coolant velocity in a water jacket by particle image velocimetry (PIV) method, are set up. An accurate and robust empirical correlation for modeling of subcooled flow boiling that occurs in the water jacket is developed. Then, through a three-dimensional (3D) thermal analysis, the heat transfer parameters such as heat flux and temperature distribution of the ICE cylinder block and head are obtained numerically. Finally, as the main achievement of this study, a diagram is presented, which combines the concept of precision cooling and subcooled flow boiling and gives the minimum coolant velocity in terms of heat flux. Without going into detailed thermo-fluid analysis, this provides a convenient tool to determine the minimum velocity of the coolant flow over the different regions of the ICE water jacket wall to keep it at its allowable temperature range.
Qasemian, Ali, Keshavarz, Ali, Setoodeh, Hamed, Mohammadi, Arash, Chitsaz, Iman
Bearings, Elastomeric General Specification forAS85598 (Current)2/11/2021
This standard defines general requirements for spherical, radial-journal, conical, and thrust bearings which are of laminated elastomeric construction. These bearings are for use in an environment having a temperature spectrum of -65 to +160 °F while reacting steady state loads in addition to oscillating loads and motions. The operating temperature range of -65 to +160 °F reflects the current temperature range for existing parts, but allows for expansion in the future.
ACBG Plain Bearing Committee
Effects of Lithium Plating Morphology on Thermal Safety for Lithium Ion Batteries2020-01-524112/14/2020
Over the last decade, the electric vehicle (EV) has significantly changed the car industry globally, driven by Li-ion battery technology's fast development. However, the fire risk and hazard associated with this type of high-energy battery has become a significant safety concern for EVs. This report focuses on the thermal safety of lithium ion battery (LIB) with different lithium plating morphology. The orthogonal experimental design method is used to control the LIBs cycle and lithium plating condition. The L34 table was designed for cycling the LIBs, considering temperature, cut-off voltage, charging rate and pressure. The safety was evaluated by accelerating rate calorimetry (ARC). The self-heating onset temperature (Tsh) and thermal runaway onset temperature (Ttr) comparison between new cells and lithium plating cells show a significant deterioration. For LIB with different lithium plating morphology, including mossy and dendrite, the time duration from Tsh to Ttr presents a valuable conclusion that Δtdendritic is lower than Δtmossy. It can be explained by exposed surface area difference for dendritic and mossy.
Wu, Peng, Dong, Peng, Zhong, Liang, Liu, Zhongxiao, Li, Zhe, Zhang, Jianbo, Wang, Zhenpo
Laboratory Testing of Vehicle and Industrial Heat Exchangers for Thermal Cycle DurabilityJ1542_202012 (Historical)12/10/2020
This SAE Recommended Practice is applicable to all liquid-to-air, liquid-to-liquid, air-to-liquid, and air-to-air heat exchangers used in vehicle and industrial cooling systems.
Cooling Systems Standards Committee
Study on the High Temperature Tensile Properties of Aerospace Grade Hastelloy X Joined by Pulsed Current Arc Welding2020-28-04219/25/2020
The fabrication or repairing of aircraft components made of Hastelloy X to be resolved using an arc welding technique. In this study, Hastelloy X was joint with ERNiCrCoMo-1 filler by pulsed current gas tungsten arc (PCGTA) welding. The high temperature tensile property of the weldment has been evaluated at three different temperatures such as 700 °C, 800 °C and 900 °C. The tensile properties such as yield strength (294, 259 and 205 MPa), ultimate tensile strength (475, 396 and 245 MPa) and percentage of elongation or ductility (17, 14 and 11 %) follows the similar trend with temperature at 700 °C, 800 °C and 900 °C respectively. It revealed the values of all the properties are decreased as the temperature increased. The lowest strength was evaluated for weldment at 900 °C. The high temperature tensile test also revealed that the fracture of weldments for all three conditions is found at the weld centre (WC). Even though, the failure happened at WC, the high temperature tensile strength of the weldments revealed that values are more or less equal to the base metal (Hastelloy X) values at 700 °C, 800 °C and 900 °C. The SEM fractography has been performed to find the tensile failure mode of weldments. The ductile dimples, ductile tear ridges and lesser cleavage-facet are found in the fractured region which derives the ductile failure.
Mathiyazhagan, Sathishkumar, Arivazhagan, Natarajan, Gokulkumar, Kesavan, Mohan, Cigurupadi Ganesan, Naiju, CD, Manikandan, Manoharan
Aviation Visual Distress Signals (AVDS)AS5134C (Current)8/25/2020
This SAE Aerospace Standard (AS) provides minimum performance and design standards for a handheld, high-intensity, flashing Aviation Visual Distress Signal (AVDS) based on light-emitting-diode (LED) technology operating simultaneously in visible (white) and near infrared (NIR) spectra designed to facilitate location and rescue of aviation accident/ditching survivors in open sea conditions.
S-9A Safety Equipment and Survival Systems Committee
Standard Test Method for Aerodynamic Acceptance of AMS1424 and AMS1428 Aircraft Deicing/Anti-Icing FluidsAS5900D (Historical)8/3/2020
This SAE Aerospace Standard (AS) establishes the aerodynamic flow-off requirements and test procedures for AMS1424 Type I and AMS1428 Type II, III, and IV fluids used to deice and/or anti-ice aircraft. The objective of this standard is to ensure acceptable aerodynamic characteristics of the deicing/anti-icing fluids as they flow off of aircraft lifting and control surfaces during the takeoff ground acceleration and climb. Aerodynamic acceptance of an aircraft ground deicing/anti-icing fluid is based upon the fluid’s boundary layer displacement thickness (BLDT) on a flat plate, measured after experiencing the free stream velocity time history of a representative aircraft takeoff. Acceptability of the fluid is determined by comparing BLDT measurements of the candidate fluid with a datum established from the values of a reference fluid BLDT and the BLDT over the dry (clean) test plate. Testing is carried out in the temperature range at which the fluid, undiluted and diluted, is to be used in airline service. NOTE: No additional testing is required for non-glycol fluids at this time. For more information about non-glycol fluids, please refer to AMS1424 and AMS1428.
G-12ADF Aircraft Deicing Fluids
Venting for EV Battery PacksTBMG-374328/1/2020
Batteries for electric vehicles (EVs) need protection from harsh external conditions. Generally located on the underside of the vehicle, EV battery enclosures protect the cells from exposure to water, dust, debris, and other elements. Like other enclosures, EV battery enclosures also undergo temperature and pressure changes that can lead to problems without proper venting. But EV batteries present unique venting challenges including potentially dangerous thermal runaway conditions. Considering these challenges, integration of design, manufacturing, installation, and testing are crucial to optimal EV battery venting performance.
Determination of Effect of Solar HeatingJ1559_202007 (Current)7/10/2020
This document specifies a test method for simulating solar heating in the laboratory and measuring the radiant heat energy from a natural or simulated source. This standard is applicable to all off-road, self-propelled work machines as listed in the scope of SAE J1116 (Rev Nov 2004) when equipped with an operator enclosure system.
HFTC6, Operator Accommodation
Water Solution Type Hand Fire ExtinguisherAS245C (Current)5/28/2020
This specification covers the following types and classes of extinguishers: Type I Stored pressure type Category A - Operational Temperature range −40 to +140 °F (−40 to +60 °C) Category B - Operational Temperature range +35 to +140 °F (+1.7 to +60 °C) Type II Cartridge operated type Category A - Operational Temperature range −40 to +140 °F (−40 to +60 °C) Category B - Operational Temperature range +35 to +140 °F (+1.7 to +60 °C)
S-9A Safety Equipment and Survival Systems Committee
Laboratory Testing of Vehicle and Industrial Heat Exchangers for Heat Transfer and Pressure Drop PerformanceJ1994_202004 (Historical)4/28/2020
This SAE Recommended Practice is applicable to all heat exchangers used in vehicle and industrial cooling systems. This document outlines the tests to determine the heat transfer and pressure drop performance under specified conditions. This document has been reviewed and revised by adding several clarifying statements to Section 4.
Cooling Systems Standards Committee
Temperature Measurement, Well Insert TypeARP175A (Current)4/14/2020
A-4 Aircraft Instruments Committee
The Isochoric Engine2020-01-07964/14/2020
For the gasoline engine, the isochoric process is the ideal limit of the ideal processes. During the project, a combustion engine with real isochoric boundary conditions is built. A “resting time” of the piston for several degrees crank angle in the top dead center (TDC) can be realized with a special crank drive. This crank drive consists of two crankshafts with different strokes, which are combined. The two crankshafts rotate with a ratio of two to one in opposite directions. The total stroke corresponds to the amount of the first crankshaft, so it is possible to investigate different strokes of the second crankshaft in the same crankcase. Different “resting times” can be achieved by different strokes of the second crankshaft. A specific combination of both crankshafts make a stroke possible which corresponds to that of a conventional combustion engine. In addition to the standard cylinder pressure sensor, a quick surface temperature probe is also used as supplementary measurement technology. The influence of isochoric combustion is studied with constant air mass and constant lambda at three different strokes of the small crankshaft.
Burger, Benjamin, Bargende, Michael
Hot Plate Method for Evaluating Heat Resistance and Thermal Insulation Properties of MaterialsJ1361_202003 (Current)3/4/2020
This test method is applicable for rating various materials, such as automotive trim materials and insulation composites, for their ability to resist heat transfer, heat degradation, odor, smoking, and exothermic reaction under prescribed temperature.
Acoustical Materials Committee
Development of a Novel Hybrid-Piston for Application in High Performance Two-Stroke Engines2019-32-05081/24/2020
The current development trends for high performance two-stroke engines have been identified in raising combustion pressures and therefore higher cylinder temperatures [1] [2]. Thus, the requirements on piston assembly are increased in such a way that pistons based on aluminium-silicon alloys – as most commonly used in high performance two-stroke engines - reach their application limit. A suitable solution has been shown by research work such as that conducted by Mahle König, by using a piston consisting of different materials. With this approach, the higher stressed piston crown consists of steel, while the lower stressed piston skirt is made out from aluminium. Previous basic examinations showed the high potential of the hybrid piston concept in terms of pressure and temperature increase, while also showing the need for a temperature-stable and pressure-tight joint between crown and skirt. This paper will focus on the development of two novel hybrid-piston concepts, where the piston crown and the piston skirt are connected in different ways. The first hybrid concept presented uses the piston pin in order to realize a plugconnection between piston crown and piston skirt (a conjunction hereafter known as plug-connection). A second approach is a material joint between piston crown and piston skirt, with the result that the two parts are integrally joined to one another (a conjunction hereafter known as multimaterial joint). During the predevelopment phase the design and dimensioning of the hybrid concepts were carried out with reference to mechanical and thermal operation loads, as well as joining aspects. A specific joining concept using a bimetal transition joint was created, along with the development of a special adapted laser beam welding procedure. The multi-material joint properties were further verified by FEM simulations as well as by mechanical and thermal tests. Finally, hybrid-piston prototypes were produced in time for first bench tests. In this paper the design concept of the hybrid piston and the joining technology will be presented, along with the results of FEM simulations and material testing.
Bechter, Christian, Jahn, Axel, Zimmermann, Frieder, Stamm, Uwe, Herb, Thomas
Dynamic Mechanical Strain-Induced Temperature Gradient CoatingTBMG-358111/1/2020
Evaluating components for discontinuities without damaging the part or system remains a priority for diverse industries and research fields. Low-cost techniques such as fluorescent penetrant inspection (FPI) are used widely by major industries, such as aviation and aerospace, despite limited defect detection and the need for complex, multi-step operations in highly controlled conditions. Nondestructive methods such as sonic infrared (SIR) testing apply ultrasound waves to identify surface defects and cracks. These techniques hold promise for widespread use but stand to improve in the detection of false positives.
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