Browse Topic: Tests and Testing

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In-Flight Evaluation of Sustainable Hydrocarbon Fuels in Compression Ignition Aircraft Engines2025-01-0533To be published on 11/25/2025
With global air traffic projected to increase significantly in the coming decades, reducing the associated climate impact requires scalable solutions. While alternative propulsion technologies such as electric and hybrid-electric systems might offer long-term potential, their current applicability remains limited due to low energy density, limited range and scalability, and system complexity. Consequently, thermodynamic propulsion systems—such as gas turbines and piston engines—are expected to remain dominant in the medium term. In this context, sustainable hydrocarbon-based aviation fuels represent a practical and necessary solution. Certified sustainable aviation fuel (SAF) pathways are currently approved exclusively for use in gas turbines, with certification standards tailored to turbine-specific requirements. Consequently, fuel properties such as cetane number and evaporation behavior are not included in existing specifications. However, when SAF-kerosene blends are used in
Kleissner, Florian, Hofmann, Peter, Vogd, Philipp, Vauhkonen, Ville, Käkölä, Jaana, Greve, Alina
Technical Paper
Road Test Emulation – A Data-Driven Calibration Approach2025-01-0521To be published on 11/25/2025
The resource-intensive process of road testing constitutes an elementary part of the development of vehicle software. A significant proportion of explorative tests and adjustments for use in service are conducted during the vehicle test phase. However, the observed trends of decreasing development cycles and increasing system complexity generate a field of conflicts. In order to address this issue, this paper proposes road test emulation as a data-driven approach for continuously adapting vehicle software to the evolving overall system. Therefore, test scenarios equivalent to in-service conditions are determined based on customer data and test drives. These test scenarios enable an emulation of road testing and the analysis of the system in a real-world operational context from the early stages of the product development process. Sensitivity analyses are utilised to generate system-specific data for the vehicle under development, which is then employed to define initial parameter
Martini, Tim, Kempf, André, Winke, Florian, Auerbach, Michael, Kulzer, André Casal
Technical Paper
Simulative temperature determination of an electric machine from test bench tests2025-01-0520To be published on 11/25/2025
One of the most important components of an electric vehicle is the drive motor. Induction motors are often used for this purpose. Power losses occur during the operation of these motors, particularly at high speeds. Among other things, this power loss corresponds to the sum of winding losses, iron core losses and mechanical losses. The power losses generate heat, causing the temperature in the rotor and stator to rise. The increase in temperature of the components inside the motor can lead to premature wear and fatigue failure. To prevent overheating, the motors are air or water cooled. Water cooling can be achieved by jacket cooling, for example. In this case, the heat generated is dissipated directly by forced convection. However, the cooling jacket makes it difficult to determine the temperature inside the motor. Determining these temperatures is necessary to prevent the motor from fatiguing prematurely. The temperatures that occur inside the motor during operation are of particular
Schamberger, Stephanie, Reuss, Hans-Christian
Technical Paper
An SVM-based approach to develop a new control module for H2-powered engine using driver behaviour classification2025-32-0042To be published on 11/03/2025
In the next years, the global hydrogen vehicle market is expected to grow at a very high rate. Consequently, it is necessary for scholars and professionals to study and test specific components in order to rise motor efficiency leveraging the new features of connectivity available in smart roads. In particular, our research is focused on the developement of an engine control module driven by evaluation of usage characteristics (e.g., driving style) and "connected-to-x" scenarios using the standard engine control approach. Moreover, the module proposed enables the implementation of "fast running" models to improve the response of vehicle and make the best possible use of H2-powered engine characteristics. That said, in this paper is proposed a new approach to implement the control module, using Support Vector Machine (SVM) as the machine learning algorithm to detect driving style, and consequently modify the parameters of the engine. We choose SVM because i) it is less prone to
Mastroianni, Michele, Merola, Simona, Irimescu, Adrian, De Santis, Marco, Esposito, Christian, Aversano, Lerina
Technical Paper
RDE testing of small Motorcycle in Indian Road Conditions and study the impact of instrumentation on emission and fuel economy2025-32-0075To be published on 11/03/2025
This paper presents the results of real-world driving emissions and fuel economy measurements for two-wheelers in India using a state-of-the-art FTIR PEMS technology. The study aimed to characterize the emissions profiles of a small motorcycle under typical Indian driving conditions, including congested urban traffic and highway driving. This is the continuation of the study conducted previously on bigger motorcycle using gas analyzer [ JSAE 20179041 / SAE 2017-32-0041][1], with necessary adaptations to suit the specific conditions of Indian roads and traffic. Key parameters such as NOx, CO, CO2 and Fuel consumption were measured during real-world driving cycles and comparison is done with standard WMTC emission testing cycle. The findings of this study provide valuable insights into the actual on-road emissions of two-wheelers in India, which can be used to inform regulatory policies, develop more accurate emission models, and guide the development of cleaner and more efficient two
AGRAWAL, RAHUL, Jaswal, Rahul, Yadav, Sachin
Technical Paper
Emission Performance of Motorcycles: Regulated and Non-Regulated Pollutants under Harmonized and Extended Testing Conditions2025-32-0069To be published on 11/03/2025
This study investigates emissions from motorcycles, focusing on both regulated gaseous pollutants (e.g., CO, NOx, HC) and particulate number (PN) emissions, which are non-regulated for this vehicle category in the actual EU emission regulation. Using a state-of-the-art testbench setup equipped with advanced exhaust gas analysis and PMP system, emissions were analyzed under both standardized homologation cycles and more dynamic Real Driving Cycles (RDCs). Besides the measurement results the technological differences between different motorcycle categories are described. This is followed by a discussion of the influences of engine and exhaust gas aftertreatment systems on emission. The findings reveal that, there are two different subcategories of two-wheeler, which show different emission characteristics. L1e vehicles showed increased emissions compared to passenger cars, caused by the absence of advanced exhaust aftertreatment and on-board diagnosis systems which is driven by less
Schurl, Sebastian, Schmidt, Stephan, Bretterklieber, Niko, Kupper, Martin, Kirchberger, Roland
Technical Paper
Experimental analysis of wheel bearing friction losses under realistic driving cycles on a component and roller test bench2025-32-0100To be published on 11/03/2025
The ongoing electrification of vehicle powertrains brings attention to components with a minor contribution to overall friction losses in research and development. To optimize the overall energy efficiency, it is essential to analyze and reduce the losses in these components. Wheel bearings are of particular interest in this context, as their friction losses affect both the driving and recuperation phases. These losses are dependent on temperature, mechanical loads and the bearing mounting situation into the vehicle. The analysis of friction losses and their dependency on the factors mentioned above is usually conducted by measurements on component test benches to allow an isolated evaluation. In contrast, the friction losses of the complete drive system are measured on powertrain or roller test benches. In this context, the factors affecting the losses in wheel bearings may deviate from the measurements obtained on component test benches. The purpose of this paper is to analyses the
Hartmann, Lukas, Erxleben, Lars, Rebesberger, Ron, Henze, Roman, Sturm, Axel
Technical Paper
Fatigue in Plastic Field of AISI 304L on an Engine Component: An Interesting Case on a Pulley for Automotive Application2025-32-0080To be published on 11/03/2025
This study investigates the failure mechanisms of a press-fitted AISI 304L pulley, which is used to drive an engine coolant variable water pump in automotive applications. The analysis focuses on the peculiar loading scheme of the pulley resulting from the innovative water pump design which combines high mean stress from press fitting with cyclic stress from rotating bending loads that exceed the material's yield point. This is coupled with the cyclic material behavior of AISI 304L which exhibit a strong cyclic hardening. This combination significantly influences the stress distribution and fatigue life of the component under cyclic loads combined with material plasticity, ultimately leading to fatigue failure at the pulley-shaft mating surface. Assembly endurance tests were conducted on a specialized test bench, allowing control of pulley bending load. A comprehensive failure analysis, including visual inspection, metallurgical examination, and finite element analysis (FEA) was
Franceschini, Alessandro, Squarcini, Raffaele, Rybicki, Gilles
Technical Paper
Development of an Artificial Calibrator for Shift Program Optimization to Enhance Fuel Efficiency2025-32-0082To be published on 11/03/2025
The calibration of automotive electronic control units is a critical and resource-intensive task in modern powertrain development. Optimizing parameters such as transmission shift schedules for minimum fuel consumption traditionally requires extensive prototype testing by expert calibrators. This process is costly, time-consuming, and subject to variability in environmental conditions and human judgment. In this paper, we introduce an artificial calibrator – a software agent that autonomously tunes transmission shift maps using reinforcement learning (RL) in a Software-in-the-Loop (SiL) simulation environment. The RL-based calibrator explores shift schedule parameters and learns from fuel consumption feedback, thereby achieving objective and reproducible optimizations within the controlled SiL environment. Applied to a 7-speed dual-clutch transmission (DCT) model of a 1.5 L Mild Hybrid Electric Vehicle (MHEV), the approach yielded significant fuel efficiency improvements. In a case
Kengne Dzegou, Thierry Junior, Schober, Florian, Rebesberger, Ron, Henze, Roman
Technical Paper
Development of an SSP-180 Synchronizer Durability Test2025-01-0408To be published on 10/07/2025
Synchronizers are designed to provide smooth, efficient and safe transfer of torque between mechanical gears. Friction level, durability, and consistency of the fluid / friction lining system are crucial to ensuring crisp gear engagements without clashing and noise, vibration and/or harshness (NVH) for the life of the transmission. Excellent wear control of gears, synchronizer ring and cone surfaces is also critical to protecting the life of moving mechanical parts. The SSP-180 synchronizer rig measures friction durability and wear up to 100,000 engagements, using a variety of fluids and friction materials. Methodology for the development of a synchronizer durability procedure using the SSP-180 rig is presented for qualifying fluids for dry dual clutch (DCT) and manual transmission (MT) applications for General Motors. It will be shown that the new SSP-180 Synchronizer Durability Test in Appendix C of the dDCT fluid specification [1] satisfies four key conditions for new mechanical
Glasgow, Michael B., Zreik, Khaled, Ezanno, Philippe Nicolas, Shelton, Robert W.
Technical Paper
Development of a virtual test rig to evaluate thermal management of a battery-electric vehicle under a heating-cooling mode2025-01-0413To be published on 10/07/2025
This work presents a systematic approach to developing a virtual test rig for evaluating the thermal performance of battery electric vehicles. A mass-produced battery-electric sport utility vehicle is tested in a chassis dynamometer, and the measured vehicle performance data are used as boundary conditions for the complete vehicle model. The detailed lithium-ion battery (LIB) pack model with its cooling system was developed and calibrated with various transient driving cycle data. The HVAC model is developed using a simplified controller to maintain the cabin temperature at 25 °C during both heating and cooling modes. The complete vehicle model is used to compare the thermal performances of the BEV under cabin heating and cooling modes for various transient driving cycles. The simulated results show that using an external cabin air circulation model can reduce the battery energy consumption and dissipated heat by 9.9% and 2.4%, respectively.
Sok, Ratnak, Kusaka, Jin
Technical Paper
Comparative Evaluation of Energy Efficiency and Performance of Electric and Counterpart Diesel Tractors2025-01-0417To be published on 10/07/2025
The objective of this trial was to compare the energy efficiency and performance of battery electric against conventional diesel tractors. Controlled road tests replicating normal operations were conducted using two electric and two diesel day-cab tractors. The test protocol was based on the TMC - Type III RP 1103A and SAE J1526 test procedures. The tests were conducted on a 110 km long route that included a 59 km hilly portion with a maximum altitude difference of 307 m. The tractors were divided into test groups of two vehicles. Trailers and drivers were switched throughout the trial between the tractors in a test group. The tests found that the two electric trucks consumed 61% and 64% less energy than their counterpart diesel trucks, respectively. Considering the production mode of electricity in Canada, the electric trucks emitted on average 82% less GHG emissions than the conventional diesel-powered tractors. The two diesel trucks showed virtually identical fuel consumption and
Surcel, Marius-Dorin, Partington, Mark, Tanguay-Laflèche, Maxime, Schumacher, Richard
Technical Paper
Influence on Electric Vehicle Performance by Reproduced Real-world Driving Wind on Chassis Dynamometer2025-01-0410To be published on 10/07/2025
The latest electric vehicles (EVs) incorporate advanced thermal management systems to regulate heat distribution throughout the vehicle, thereby improving driving range. A key factor influencing thermal performance is the effect of driving wind during motion. However, evaluations of EV performance are often conducted using a chassis dynamometer (CHDY), where it remains unclear whether the driving wind specifications defined in the current Worldwide Harmonized Light Vehicles Test Procedure (WLTP) framework adequately replicate real-world conditions. This study investigates the vehicle performance of both internal combustion engine vehicles and EVs to verify the wind requirements of the WLTP. Specifically, we simulated the wind speed at the front and underside of the vehicle under real-world driving conditions, and modified the vehicle-cooling fan of the CHDY. We analyzed the impact of these modifications, and we discussed the future considerations for refining the driving wind
Okui, Nobunori
Technical Paper
Simulation study of wheel bearing friction losses at vehicle level2025-01-0399To be published on 10/07/2025
With the ongoing electrification of vehicles, components contributing a minor share of overall drivetrain losses are coming into focus. Analyzing these losses is crucial for enhancing the energy efficiency of modern vehicles and meeting the increasing demands for sustainability and extended driving range. These components include wheel bearings, whose friction losses are influenced by parameters such as temperature, mechanical loads, and mounting situation. Therefore, it is essential to analyze the resulting friction losses and their dependence on the mentioned influencing parameters at an early stage of development, both through test bench measurements and with the help of simulation models. To achieve these objectives, this submission presents a methodology that combines test bench measurements with a measurement-based simulation of the friction losses of wheel bearings occurring in the vehicle as a complete system under varying driving cycles and parameters. For this purpose, an
Hartmann, Lukas, Sturm, Axel, Henze, Roman, Notz, Fabian
Technical Paper
A Study on the Prediction Method of Durability Characteristics of Brake Judder using Simulation2025-01-0346To be published on 09/15/2025
In order to predict the durability characteristics of the brake judder, it is determined by analyzing the brake DTV (Disc Thickness Variation) and BTV(Brake Torque Variation) through the durability evaluation of the brake system or the vehicle. However, this method requires the real products and takes a long time to derive the result. When judder problems occur due to durability, there are many difficulties in deriving improvement plans through test methods. Therefore, in this study, CAE was used to derive the initial wear amount of the disc, and a method of predicting DTV after durability was developed using the results.
Hwang, Jaekeun, Kim, Sungho, Kim, Jeongkyu, Kang, Donghoon
Technical Paper
Enhancing Robustness of Electro-Hydraulic Brake-by-Wire Actuators via Linear Active Disturbance Rejection Control2025-01-0341To be published on 09/15/2025
In recent years, motorsport has increasingly focused on environmental concerns, leading to the rise of hybrid and fully electric competitions. In this scenario, electric motors and batteries take a crucial role in reducing the environmental impact by recovering energy during braking. However, due to inherent limitations, motors and battery cannot fully capture all braking power, necessitating the use of standard friction brakes. To achieve an efficient balance between electric motors and friction brakes, the brake pressure can no longer be directly controlled by the driver. Instead, it must be computed by the Vehicle Control Unit (VCU) and sent to a smart actuator, i.e. the Brake-By-Wire (BBW), which ensures that the required pressure is applied. The standard approach to achieve precise pressure control is to design a nested Proportional-Integral-Derivative (PID) control architecture, which requires an accurate nominal model of the system dynamics to meet the desired tracking
Gimondi, Alex, Dubbini, Alberto, Riva, Giorgio, Cantoni, Carlo
Technical Paper
A Novel Simulation Method for Vehicle Brake Wear Emissions2025-01-0361To be published on 09/15/2025
The effective reduction of particulate emissions from modern vehicles has shifted the focus to tire, brake, road wear and re-suspended particulate emissions. To meet future EU air quality standards and even stricter WHO targets for PM2.5, a reduction in non-exhaust particulate (NEP) emissions seems to be essential. For this reason, the EURO 7 emissions regulation contains limits for PM and PN emissions from brakes and tire abrasion. Graz University of Technology develops test methods, simulation tools and evaluates technologies for the reduction of brake wear particles and is involved in and leads several international research projects on this topic. The results are applied in emission models such as HBEFA (Handbook on Emission Factors). In this paper, we present our brake emission simulation approach, which calculates the power at the wheels and mechanical brakes, as well as corresponding rotational speeds for vehicles using longitudinal dynamics equations integrated in the
Landl, Lukas, Ketan, Enis, Hausberger, Stefan, Dippold, Martin
Technical Paper
Development of a laboratory brake for a flywheel mass test rig for variable pad sizes and shapes with a force distribution unit for ideal contact pressure and a topography measurement system for in-situ recording of surface changes and wear2025-01-0331To be published on 09/15/2025
Pin-on-disc tribometers are used to determine the frictional behaviour and boundary layer dynamics of material pairings. Material pairings are examined under defined conditions in order to make statements about the friction behaviour and wear. Pairings for real brake systems with larger pad sizes can be tested on flywheel mass test benches in order to provide proof of suitability. This is mainly due to a lack of knowledge about the scaling behaviour of friction linings. The Department of Machinery System Design at TU Berlin has combined the classic approach of a pin-on-disc tribometer with a flywheel mass test rig (up to 12.78 kgm²) and thus set up a laboratory brake on which material pairings with different pad shapes and sizes (up to 48 cm²) can be examined. The flywheel mass test stand consists of an adjustable DC-motor that drives a shaft on which variable flywheel masses and brake disks can be installed. The variability allows for different kinetic energies at different friction
Heuser, Robert Michael, Rosenthal, Tobias Richard, Wiest, Daniel Christian, Meyer, Henning Jürgen
Technical Paper
Optimum design and sizing approach for a series-hybrid vehicle2025-24-0099To be published on 09/07/2025
The need to reduce pollutant emissions has pushed the automotive industry towards sustainable mobility promoting new technological solutions, among which the use of hybrid powertrains stands out. The development of a hybrid architecture is very complex and demands proper components sizing and the determination of optimized power-split strategies among different power sources, for example: Internal Combustion Engine (ICE), electric generator/motor and batteries. Moreover, the experimental analysis regarding performance and emissions requires that the whole propulsive system must be set up on the test bench, hence, negatively affecting the cost of the entire design phase. In this scenario, an optimum design and sizing approach for a series-hybrid electric vehicle (S-HEV) is proposed aiming at a design cost reduction. The presented procedure relies on numerical modelling of the hybrid powertrain and on the optimization of the fuel consumption and the driving range. The series-hybrid
Lisi, Leonardo, Saponaro, Gianmarco, Episcopo, Domenico, Torresi, Marco, Camporeale, Sergio Mario
Technical Paper
Experimental Analysis and Model-Based Characterization of the Toyota Mirai II's Electric Machine2025-24-0136To be published on 09/07/2025
The electrification of the transportation sector relies on extensive research and data availability to accelerate technological advancements. However, for certain key components such as electric machines, detailed operational information remains scarce, which in turn limits the development of accurate system-level models for electrified powertrains. As a contribution to addressing this challenge, this study presents an experimental benchmark of the electric machine in the second-generation Toyota Mirai, a fuel cell hybrid electric vehicle (FCHEV) featuring a variable DC voltage bus, which was tested on a roller test bench. The proposed methodology aims to characterize the electric machine with minimal instrumentation and prior knowledge of the machine's configuration, by identifying electrical and geometric parameters that are relevant for a steady-state model of the machine, applicable to system-level studies, with the objective of providing a methodology that can be used in future
Carlos Da Silva, Daniel, Kefsi, Laid, Sciarretta, Antonio
Technical Paper
DLR Tire Road Wear Particle Emission Testing Methodology – Collection System Influence and Repeatability Assessments2025-24-0092To be published on 09/07/2025
Tire and road wear particles (TRWP) have emerged as air quality hazardous matters and significant sources of airborne microplastic pollution, contributing to environmental and human health concerns. Regulatory initiatives, such as the Euro 7 standards, emphasize the urgent need for standardized methodologies to quantify TRWP emissions accurately. Despite advancements in measuring tire abrasion rates, critical gaps persist in the characterization of airborne TRWP, particularly regarding the influence of collection system design and influencing parameters on measurement accuracy and repeatability. This study addresses these challenges by designing a controlled methodological framework that aims to minimize the influencing effects and ensure comparability in TRWP emission quantification results. At the German Aerospace Center (DLR) dynamometer testbench in Stuttgart, Germany, a methodical framework was established to ensure the repeatability and comparability of TRWP measurements
Celenlioglu, Melis Seren, Epple, Fabius, Reijrink, Nina, Löber, Manuel, Reiland, Sven, Vecchi, Roberta, Philipps, Franz
Technical Paper
AeroSolfd: Advancing Air Quality through Retrofitted Gasoline Particulate Filters – Insights from Laboratory and Real-World Evaluations2025-24-0088To be published on 09/07/2025
The AeroSolfd project, an EU-funded initiative, aims to improve air quality by reducing particulate emissions from in-use light-duty vehicles (LDVs). In response to growing concerns over air pollution and its environmental and health impacts, the project focuses on retrofitting Gasoline Particulate Filters (GPFs) as a viable solution. A key component of the project was an in-depth measurement campaign conducted at the BFH Exhaust Emissions Test Center on four representative vehicles—two with direct petrol injection and two with intake manifold injection. The campaign assessed non-aged GPFs under laboratory conditions using the Worldwide Harmonized Light Vehicles Test Procedure (WLTC) and Steady State Cycle (SSC), as well as in real driving environments (RDE). Fourier-Transform Infrared Spectroscopy (FTIR) was used to analyze non-regulated emissions. The results demonstrated a significant reduction in particle numbers without adverse effects on gaseous emissions. Beyond controlled
Engelmann, Danilo, Mayer, Andreas, Comte, Pierre, Rubino, Lauretta, Larsen, Lars
Technical Paper
Simulation of Swirl and Discharge Coefficient Trade-off for Diesel Engine Intake Ports2025-24-0007To be published on 09/07/2025
In Diesel engines, charge motion usually consists of swirl and squish flow patterns. Traditionally, swirl generation is controlled through the design of the intake ports, presenting a trade-off between swirl and mass flow rate. An alternative approach to generate swirl is to use vortex-generating jets in the intake port. As a comparative basis for this approach a Pareto front was established between swirl and mass flow rate based solely on geometric variations. A new fully parametric geometry was deployed, with two intake ports per cylinder adhering to some constraints. Stationary flow-bench test setup was modeled, where a blower draws air through the intake ports at a constant pressure difference. The Pareto front was generated using semi-randomly selected geometries in combination with automated unsteady RANS (URANS) simulations, while scale adaptive simulations (SAS) were also employed on select geometries. These turbulence modeling approaches were explored using the OpenFOAM
Kahraman, Ali Berk, Ritter, Johann, Eilts, Peter, Scholz, Peter
Technical Paper
Innovative Full-GaN Inverter Development for 800V/100kW Automotive Applications2025-24-0133To be published on 09/07/2025
This abstract presents the development of an automotive traction inverter utilizing cutting-edge full-GaN technology, incorporating components from CGD for high-performance 800V applications. The inverter employs a three-level topology, which is a significant advancement over the conventional two-level designs predominantly used in the current state of the art. This design aims to enhance efficiency, reduce power losses, and improve thermal management compared to traditional IGBT and SiC-based inverters. In this article is detailed a scientific approach which focused on developing a mock-up to validate the power scaling of GaN components, to the complete design of a full-scale prototype representing an automotive traction inverter. Comparative analysis in the article demonstrates that the GaN-based three-level inverter not only surpasses traditional two-level IGBT and SiC inverters in terms of efficiency and thermal performance but also shows promising potential in improving signals
Battiston, Alexandre, Aghaei Hashjin, Saeid, Findlay, John, Haje Obeid, Najla, Siad, Ines
Technical Paper
Model-based optimization of Diesel/OMEx fuelled CI engine under multiple blending conditions2025-24-0038To be published on 09/07/2025
The search for alternative solutions for vehicle electrification, while reducing the carbon footprint during the transition to green mobility, leads to the investigation of electro-fuels (e-fuels) in conventional internal combustion engines. Leveraging previous research, the present study focuses on the optimisation of a Compression Ignition (CI) engine combustion control in response to the use of the Oxymethylene Dimethyl Ethers (OMEx) blended with conventional diesel. The selected e-fuel is the OME3, which is expected to be used as a drop-in solution and to easily achieve a reduction in soot emissions due to both its high oxygen content and lack of direct carbon bonds in its molecular structure. To verify its potential, a 1D single-cylinder CI multi-zone engine model has been exploited to simulate various diesel/OME3 blends in a wide engine operating range. The first step deals with the evaluation of performance and emissions to demonstrate the differences, particularly in terms of
Foglia, Antonio, Cervone, Davide, Frasci, Emmanuele, Arsie, Ivan, Polverino, Pierpaolo, Pianese, Cesare
Technical Paper
Visualization Analysis of Hydrogen Combustion Triggered by Non-Controlled Hotspots Using a Rapid Compression Expansion Machine2025-24-0047To be published on 09/07/2025
Research on hydrogen-fueled internal combustion engines has gained growing attention as a carbon-neutral solution to reducing emissions in the transport sector. However, challenges remain, with the risk of abnormal combustion being one of the major criticalities. This paper aims to clarify the pre-ignition process of a hydrogen-air mixture caused by lubricant oil droplets and soot deposition. To achieve this, high-speed imaging methods were applied with a Rapid Compression Expansion Machine under engine-like conditions. Direct imaging and OH* chemiluminescence were captured simultaneously on the engine head to visualize the ignition point and flame propagation. Different operating conditions were tested to evaluate the influence of lambda, intake pressure, and soot quantity on pre-ignition occurrence. For each test bench configuration, ten successive tests were conducted to assess the probability of preignition occurrence. The presence of soot was ensured through a preliminary run with
Tempesti, Claretta, Yukitani, Takumi, Horibe, Naoto, Romani, Luca, Ferrara, Giovanni, Kawanabe, Hiroshi
Technical Paper
A 0D Methodology for Estimating Critical Parameters in Thermal Runaway Tests of Lithium-Ion Batteries in Closed Volumes2025-24-0150To be published on 09/07/2025
The growing push for electrification, driven by the need to reduce emissions associated with combustion engines, has accelerated the adoption of lithium-ion batteries (LIBs). However, this rapid development raises significant safety concerns, particularly regarding thermal runaway events. This study presents a zero-dimensional (0D) methodology for estimating critical parameters during thermal runaway tests conducted in sealed volumes, such as canister-based experiments where both gas composition and pressure are analyzed. The proposed methodology relies on 0D combustion calculations, incorporating experimentally observed vent gas compositions and vented mass quantities. The primary results establish approximate values for critical parameters, providing an order-of-magnitude estimation of overpressure during tests. These findings are crucial for the proper pre-dimensioning of test facilities designed for thermal runaway experiments in confined volumes. As a key conclusion, this study
Garcia, Antonio, Micó, Carlos, Marco-Gimeno, Javier, Gómez-Soriano, Alejandro
Technical Paper
Investigation of the Combustion Process of a Thermally Conditioned Active Prechamber in Monovalent Operation with Ammonia2025-24-0028To be published on 09/07/2025
The debate over synthetic fuels is intense especially in sectors with a high energy demand like maritime. Hydrogen production from renewable sources is growing, but immediate measures for decarbonization are needed. In this context, the project MethMag was funded, and a gas engine for methane combustion with an innovative cooling concept and a purged pre-chamber spark plug was virtually developed. Validation with data from the test bench demonstrates that the simulations accurately represent the operating conditions. This combustion process is adapted for ammonia, which is being considered as a climate-friendly fuel of the future, particularly in maritime transportation. This fuel faces significant combustion challenges and is therefore mostly considered in complex, bivalent systems. In particular, the pre-chamber is examined regarding the ignitability of ammonia. The transition to ammonia highlights the need for further adjustments. The geometry of the pre-chamber cap significantly
Rothe, Paul, Bikas, Georgios, Mauss, Fabian
Technical Paper
Experimental Study of the Lubricating Oil Impact on the Unsteady Performance of an Automotive Turbocharger2025-24-0078To be published on 09/07/2025
Turbocharging technique is a key technology for the development of hydrogen engines, allowing high lambda values to reach low NOx emissions. In ultra-lean mixture conditions, the thermal management of the lubricating oil and its cold condition becomes a crucial aspect that cannot be neglected. Accordingly, the impact of different lubricating oils and different lubricant thermal conditions is highlighted referring to the performance of a turbocharging system for automotive application. To this aim, an experimental campaign is conducted at the test bench for components of propulsion systems of the University of Genoa. Tests are performed on a turbocharger equipped with a variable geometry turbine under both steady and unsteady flow conditions, considering different positions of the turbine regulating device. A 4-cylinder engine head was coupled to the turbocharger in order to reproduce the pulsating flow related to the opening and closing of the engine valves. The influence of the
Marelli, Silvia, Usai, Vittorio, Cordalonga, Carla
Technical Paper
Integrated CFD-Experimental Methodology for Hydrogen-Fuelled Small Loop Scavenged Two-Stroke Engines2025-24-0014To be published on 09/07/2025
This paper presents an integrated methodology for the analysis of hydrogen-fuelled two-stroke engines, combining experimental data, 1D CFD simulations, and 3D CFD combustion calculations. The proposed approach aims to enhance the understanding of scavenging, injection, and combustion processes in a 50 cc loop-scavenged engine with low-pressure direct hydrogen injection (LPDI), experimentally studied on a test bench. The performance of the hydrogen-fuelled engine was slightly lower compared to gasoline operation, achieving a maximum power output of 3.1 kW compared to 3.6 kW with gasoline, using a slightly lean air-fuel ratio (lambda = 1.3). The maximum engine speed for stable combustion without knocking was achieved at wide-open throttle (WOT) at 7000 RPM. The developed 1D CFD model, based on the layout at the test bench, was calibrated using average experimental data and specific full-load operating points. 3D CFD simulations were performed for two full-load operating points, focusing
Caprioli, Stefano, Ferretti, Luca, Scrignoli, Francesco, Fiaschi, Matteo, D'Elia, Matteo, Oswald, Roland, Schoegl, Oliver, Nambully, Suresh Kumar, Rothbauer, Rainer, Mattarelli, Enrico, Kirchberger, Roland, Rinaldini, Carlo
Technical Paper
Design of a pure synchro-reluctant machine with asymmetrical poles for high-speed applications2025-24-0129To be published on 09/07/2025
In this article, the authors present the various choices made to design a magnet free and directly recyclable pure synchro-reluctant (Pure-SynRel) machine with asymmetrical poles operating at a maximum speed of 21,000 rpm dedicated to automotive. This project was carried out by identifying design levers and optimizing the magnetic circuit in order to remove 3 well know issues of this topology: maximizing the power factor to reduce the inverter rating and cost, minimizing sources of NVH and torque ripples in particular, and finally maximizing the efficiency in use to close the gap with magnet technologies (PMaSynRel). The sizing of stator components such as the choice of winding (concentric or distributed, full or fractional pitch, round or hairpin wire) and rotor components (number of poles pairs, shape and number of barriers, etc.) are explained. The optimizations methods and the mechanical solutions used to reach the max speed are also detailed. A machine with symmetrical poles was
Applagnat-Tartet, Antoine, Milosavljevic, Misa, Delpit, Pierre
Technical Paper
Numerical and Experimental Investigation of a Pre-chamber Igniter for Enhanced Low Load Stability in Internal Combustion Engines2025-24-0002To be published on 09/07/2025
Developing innovative ignition technologies offers a crucial opportunity to improve the performance of internal combustion engines while significantly reducing harmful emissions, contributing to a more sustainable future. The replacement of the standard spark plug with a pre-chamber igniter is a well-known combustion accelerator for externally ignited engines for passenger vehicles. An increase in engine efficiency, especially at high loads, can be realized. However, pre-chamber ignition technology has not yet been widely adopted in the market, primarily due to the difficulty of achieving stable operation at lower engine loads. A better understanding of the flow and mixture conditions is needed to improve the combustion stability with the pre-chamber igniter in low-load operating conditions. The gas exchange in the passive pre-chamber was studied using a combination of numerical modelling and experimental methods. Accessing those parameters experimentally requires a high effort in test
Fellner, Felix, Härtl, Martin, Jaensch, Malte, D'Elia, Matteo, Burgo Beiro, Marcos, Nambully, Suresh Kumar, Rothbauer, Rainer
Technical Paper
Method to Analyze Driving Dynamics During Faults in the Electric Drivetrain on a Vehicle-in-the-Loop Test Bench2025-24-0123To be published on 09/07/2025
The mechanical components of drive systems for electric vehicles are less complex than those of conventional drives and are therefore generally less prone to faults. On the other hand, a challenge lies in the relatively limited experience in dealing with faults in the electric drivetrain and their effects on driving dynamics compared to conventional drives. To meet these challenges, this paper presents a method to simulate faults in the electric powertrain of a real demonstrator vehicle on a full vehicle test bench and to evaluate the influence on driving dynamics. For this purpose, the demonstrator vehicle was modeled in detail in a co-simulation between the driving dynamics simulation software CarMaker and the real-time solution for simulating and testing electrical components Typhoon HIL. This enabled the investigation of the vehicle’s behavior in the event of a fault. Subsequently, tests with the vehicle were performed on the Vehicle-in-the-Loop full vehicle test bench and the
Rautenberg, Philip, Konzept, Anja, Hitz, Arne, Frey, Michael, Reick, Benedikt
Technical Paper
Balancing Machines – Description and Evaluation Vertical, Single-Plane, Non-Rotating Type for Gas Turbine RotorsARP6217 (Current)08/13/2025
Characteristics of vertical non-rotating balancing machines are described which make such machines suitable for balancing rigid unbladed gas turbine rotors or rotors with fixed, integral blades.
EG-1A Balancing Committee
Recommended Practice
Validation of a Suspension Lifter Bracket through a Test Bench2025-36-030608/01/2025
In the Brazilian market, the 6x2 configuration for commercial vehicles is widely used. These vehicles feature a driven rear axle and a non-driven axle. For the non-driven axle, it is common to use a lifter system that allows the axle to be lifted when the vehicle is running empty. This system provides benefits such as reduced fuel consumption, lower tire wear, and reduced toll costs when charges are based on the number of axles in contact with the ground. Given these advantages, the system has a high demand, making it mandatory to perform a durability test prior to its market implementation. This paper will present the validation methodology for the lifter system bracket. To achieve this, the following stages will be discussed: CAE, instrumentation, data acquisition, test bench concept, test execution and results.
Leme, Cristiano, da Costa Rodrigues, Gilson, Figueiredo, Guilherme Galvão, de Souza Maria, Heitor Cunha, Pires, Luciano Rogério
Technical Paper
Recommended Test Requirements for Electromechanical ActuatorsARP5724A (Current)07/22/2025
This Aerospace Recommended Practice (ARP) provides recommended requirements for the testing of electromechanical actuators (EMAs). General test considerations are also provided. While many EMA configurations include motor control electronics, the specific tests required for the electronic hardware, software, or firmware are outside the scope of this document.
A-6B3 Electro-Mechanical Actuation Committee
Recommended Practice
Qualifications Required for SAE Type I Aircraft Deicing/Anti-Icing FluidsARP6207A (Current)07/22/2025
This document describes: a The preparatory steps to test experimental Type I fluids according to AMS1424; b The recommendations for the preparation of samples for endurance time testing according to ARP5945; c A short description of the recommended field spray test; d The protocol to demonstrate that Type I fluid can be used with the Type I holdover time guidelines published by the FAA and Transport Canada, including endurance time data obtained from ARP5945; e The protocol for inclusion of Type I fluids on the FAA and Transport Canada lists of fluids; f The protocol for updating the FAA and Transport Canada lists of fluids; g The role of the SAE G-12 Aircraft Deicing Fluids Committee; h The role of the SAE G-12 Holdover Time Committee; and i The process for the publication of Type I holdover time guidelines. This document does not describe laboratory-testing procedures. This document does not include the qualification requirements for AMS1428 Type II, III, and IV fluids (these are
G-12HOT Holdover Time Committee
Recommended Practice
Cab Roof Strength Evaluation - Quasi-Static Loading Heavy TrucksJ2422_202507 (Current)07/22/2025
This SAE Recommended Practice describes the test procedures for conducting quasi-static cab roof strength tests for heavy-truck applications. Its purpose is to establish recommended test procedures that will standardize the procedure for heavy trucks. Descriptions of the test setup, test instrumentation, photographic/video coverage, and test fixtures are included.
Truck Crashworthiness Committee
Recommended Practice
Qualifications Required for SAE Type II/III/IV Aircraft Deicing/Anti-Icing FluidARP5718C (Current)07/17/2025
This document describes: a The preparatory steps to test experimental Type II, III, and IV fluids according to AMS1428 b The recommendations for the preparation of samples for endurance time testing according to ARP5485 c A short description of wind tunnel testing d A short description of the recommended field spray test e The protocol to generate draft holdover time guidelines from endurance time data obtained from ARP5485 f The protocol for inclusion of Type II, III, and IV fluids on the FAA and Transport Canada lists of fluids and the protocol for updating the lists of fluids g The role of the SAE G-12 Aircraft Deicing Fluids Committee h The role of the SAE G-12 Holdover Time Committee i The process for the publication of Type II, III, and IV holdover time guidelines This document does not describe laboratory testing procedures. This document does not include the qualification requirements for AMS1424 Type I fluids (these are provided in ARP6207).
G-12HOT Holdover Time Committee
Recommended Practice
Alloy, Corrosion- and Heat-Resistant, Investment Castings 30Fe - 21Cr - 20Ni - 20Co - 3.0Mo - 2.5W - 1.0Cb - 0.15N (N-155) As-CastAMS5376J (Current)07/16/2025
This specification covers a corrosion- and heat-resistant iron alloy in the form of investment castings.
AMS F Corrosion and Heat Resistant Alloys Committee
Material Specification
Nickel Alloy, Corrosion- and Heat-Resistant, Investment Castings 73Ni - 0.14C - 13Cr - 4.5Mo - 2.3Cb (Nb) - 0.75Ti - 6.0Al - 0.010B - 0.10Zr (IN-713) Vacuum Cast, As-CastAMS5391J (Current)07/16/2025
This specification covers a corrosion- and heat-resistant nickel alloy in the form of investment castings.
AMS F Corrosion and Heat Resistant Alloys Committee
Material Specification
Nickel Alloy, Corrosion- and Heat-Resistant, Investment Castings 47.5Ni - 22Cr - 1.5Co - 9Mo - 0.60W - 18.5Fe (Hastelloy® X) As-CastAMS5390H (Current)07/16/2025
This specification covers a corrosion- and heat-resistant nickel alloy in the form of investment castings.
AMS F Corrosion and Heat Resistant Alloys Committee
Material Specification
SAE No. 2 Friction Test Machine 3600 rpm Stepped Power TestJ2487_202507 (Current)07/16/2025
This SAE Recommended Practice is intended as the definition of a standard test, but it may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use. The SAE No. 2 Friction Test Machine is used to evaluate the friction characteristics of automatic transmission plate clutches with automotive transmission fluids. It can also be used to conduct durability tests on wet friction systems. The specific purpose of this document is to define a 3600 rpm stepped power test for the evaluation of wet friction system performance variation as a function of power level. This procedure uses an initial engagement speed of 3600 rpm and is intended as a standard procedure for common use by both suppliers and end users. The only variables selected by the supplier or user of the friction system are: a Friction material b Fluid c Reaction plates These three variables must be clearly identified when reporting the results of using
Automatic Transmission and Transaxle Committee
Recommended Practice
Brief Communication: Measurement of Boundary Layer Turbulent Transition Using an Acoustic Microphone Unit01-18-02-001107/16/2025
In this article the transition of a laminar boundary layer (BL) over a flat plate is characterized using an acoustic technique with a pitot probe linked to a microphone unit. The probe was traversed along a BL plate at a fixed wind tunnel flow velocity of 5.5 m/s. A spectral analysis of the acoustic fluctuations showed that this setup can estimate the streamwise location and length of the BL transition region, as well as the BL thickness, by using the intermittency similitude approach. Further work is required to quantify the uncertainty caused by signal attenuation within the data acquisition system.
Lawson, Nicholas John, Zachos, Pavlos K.
Journal Article
Ethanol Fuel as Enabler for High-Efficiency and Low-Soot Combustion in Dual-Fuel and Blend Modes03-18-04-002807/16/2025
Global climate initiatives and government regulations are driving the demand for zero-carbon tailpipe emission vehicles. To ensure a sustainable transition, rapid action strategies are essential. In this context, renewable fuels can reduce lifecycle CO2 emissions and enable low-soot and NOx emissions. This study examines the effects of renewable ethanol in dual-fuel (DF) and blend fueling modes in a compression ignition (CI) engine. The novelty of this research lies in comparing different combustion modes using the same engine test rig. The methodology was designed to evaluate the characteristics of various injection modes and identify the inherent features that define their application ranges. The investigation was conducted on a single-cylinder engine equipped with state-of-the-art combustion technology. The results indicate that the maximum allowable ethanol concentration is 30% in blend mode, due to blend stability and regulatory standards, and 70% in DF mode, due to combustion
Belgiorno, Giacomo, Ianniello, Roberto, Di Blasio, Gabriele
Journal Article
Clamp Assembly, Loop Type, Cushioned, General Specification forAS85052C (Current)07/14/2025
This SAE Aerospace Standard (AS) defines the requirements for loop-type clamps primarily intended for general clamping of tubing for aircraft hydraulic systems.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Technical Standard
Dynamic Test Procedure for Acrylonitrile Butadiene Rubber (NBR) Composition SealsAS6944/1 (Current)07/14/2025
This SAE Aerospace Standard (AS) provides a standardized test procedure that can be used to evaluate material capability in a dynamic sealing application. This procedure will be utilized by applicable elastomer material specifications which are used for production of O-rings and other seals. This specification is applicable to the dynamic testing requirements for aerospace elastomer parts utilizing materials conforming to AMS7XXX series specifications, user specifications, or print on a Purchase Order (PO) that calls out this document for aerospace applications. This procedure is intended for testing NBR. Other elastomers may have different requirements which will require a separate procedure.
AMS CE Elastomers Committee
Technical Standard
Thermal Interaction Based on Battery Electrochemical Modeling for In-Wheel Hub Motor Electric Vehicles: A Performance Analysis14-14-03-001607/09/2025
As the adoption of battery electric vehicles (BEVs) continues to rise, analyzing their performance under varying environmental conditions that affect energy consumption has become increasingly important. A critical factor influencing the efficiency of BEVs is the heat loss from the operation and interaction between the vehicle components, such as the battery and motor, and the surrounding temperature. This study presents a comprehensive analysis of the thermal interaction in BEVs by integrating hub motor vehicle and battery electrochemical model with environmental factors. It explores how ambient temperature variations influence the performance of EV components, particularly the motors and battery systems, in both hot and cold weather conditions. The simulations also consider the passenger comfort inside the cabin as it investigates the effects of operating the air-conditioning system on overall energy consumption, revealing significant energy consumption shifts during extreme ambient
Abdullah, Mohamed, Zhang, Xi
Journal Article
Experimental Investigations on the Effects of Injector Design and Operating Parameters on PCCI Combustion in a Light-Duty Diesel Engine03-18-04-002607/09/2025
Due to increasingly stringent emission regulations, advanced combustion strategies, such as premixed charge compression ignition (PCCI), have emerged promising solutions for achieving low NOx and soot emissions. However, challenges such as increased unburned hydrocarbon (HC), carbon monoxide (CO) emissions, and a restricted engine operating load range remain unsolved. Since conventional diesel engines are not inherently designed for PCCI operation, re-optimizing engine parameters is essential. The primary objective of this work is to investigate the influence of injector orientation and nozzle spray angle on combustion parameters, performance, and emissions in a PCCI diesel engine. Initial parametric studies revealed that early direct injection combined with high fuel injection pressure limited the PCCI load range to 30% and 60% of the rated capacity with diesel, without and with EGR, respectively, accompanied by higher HC and CO emissions. To address these limitations, the injector
Ranjan, Ashish Pratap, Krishnasamy, Anand
Journal Article
Investigation of Expansion Characteristics of Convergent–Divergent Nozzles with a Variable Geometry Sudden Expanded Duct01-18-02-001007/09/2025
In recent years, there has been a significant rise in research focused on estimating the base pressure (Pb) characteristics of convergent–divergent nozzles with sudden expansion regions. This study explores the use of geometrical parameters as a control strategy for nozzles experiencing abrupt expansion at supersonic Mach numbers within an axisymmetric duct. It focuses on four distinct novel expansion duct configurations: square nozzle (SN), step square nozzle (SSN), curved nozzle (CN), and double curved nozzle (DCN). In this work, the high-speed compressible flow investigation is carried out numerically using control volume method on the nozzle with a fixed area ratio (AR) and L/D nozzle. Standard k-ε turbulence model is used in the analysis to access the recirculation region formed near the nozzle walls. The recirculation zone directly influences the Pb and shock cell. For NPR range from 2 to 10, SSN and CN shows an increase in Pb, which further increases the thrust and decreases the
Raj, R. Jini, Kumar, P. Deepak, Panchksharayya, D. V., Kousik Kumaar, R., Praveen, N.
Journal Article
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