Data-driven Modeling of Thermal Fuses

<div class="htmlview paragraph">The 1975 federal CVS test procedure and emission standards have placed a heavy emphasis on minimizing the time required after engine start up to begin converting exhaust emissions. Four major improvements in catalytic HC/CO converters have been made in the past year to reduce catalyst ignition time:</div> <div class="htmlview paragraph"> <ol class="list nostyle"> <li class="list-item"> <span class="li-label">1.</span> <div class="htmlview paragraph">Use of low thermal capacity monolithic catalyst supports.</div> </li> <li class="list-item"> <span class="li-label">2.</span> <div class="htmlview paragraph">Locating converter after thermal reactor and/or closer to the exhaust manifold.</div> </li> <li class="list-item"> <span class="li-label">3.</span> <div class="htmlview paragraph">Development of catalysts with superior stability to long exposure at high temperatures.</div> </li> <li class="list-item"> <span class="li-label">4.</span> <div class="htmlview paragraph">Development of catalysts with improved low temperature activity.</div> </li> </ol> </div> <div class="htmlview paragraph">Small laboratory samples of potential HC/CO oxidation catalysts were screened for activity in a “laboratory simulated cold-start” test with exhaust from a 2-cyl engine. Several improved catalyst candidates were evaluated in a full-size converter “cold-start” test with exhaust from a 351 in<sup>3</sup> engine.</div> <div class="htmlview paragraph">Locating the converters closer to the exhaust manifold results in higher catalyst operating temperatures which require greater stability at high temperatures in the presence of trace contaminants. Stability, when exposed to wide temperature variations and changes from oxidation to reduction environments, has been evaluated in a thermal-cycling test for several improved catalysts. Catalyst stability to long-term exposure has also been evaluated in an engine dynamometer mileage accumulation test operated under simulated road conditions.</div> <div class="htmlview paragraph">Unfortunately, the rapid thermal-chemical response of the improved catalyst, operated closer to the exhaust manifold, increases the occurrences of excessive catalyst temperatures. Mathematical model studies of the effect of the improved catalyst properties on thermal response indicate a need to prevent unexpected high CO or HC concentration peaks in the engine exhaust, or to improve properties of existing catalysts. System changes, such as moving the low temperature catalyst farther from the exhaust manifold, may be required to obtain some protection from catalyst overtemperatures. These changes increase emission levels and require a breakthrough in engine control of raw emissions or improved catalysts.</div>

<div class="section abstract"><div class="htmlview paragraph">In recent years the 2-wheelers engines companies have been focused on increasing the overall engine efficiency, that can be achieved amongst other by engine down-speeding, engine down-sizing and by reducing the frictions; however, to maintain or improve vehicle performance, it is necessary to provide a corresponding increase in specific power.</div><div class="htmlview paragraph">In accordance with these trends, the studied approaches and methodologies have been exploited, during the development of the new Piaggio small scooter engine.</div><div class="htmlview paragraph">In this work a multi-objective analysis has been applied to the valve train system design, in order to optimize the engine performance in terms of friction reduction, power curve and timing system response. Along with this optimization methodology, a robust design has been studied to make the peak cranking compression pressure insensitive to the engine starting device working. These calculation methodologies have been followed using commercial software as GT-SUITE® code and the modeFRONTIER® platform for the multi-objective optimization analysis.</div><div class="htmlview paragraph">The several configurations investigated have allowed to reach the desired trade-off between the appropriate and efficient valve train behavior and the engine performances.</div><div class="htmlview paragraph">The global engine friction reduction has been obtained thanks to low resisting cam torque profiles, a specific valve springs set and a new compression releaser device (during engine starting phase).</div><div class="htmlview paragraph">The results have been further validated by an experimental campaign carried out on the test bench for engine performance and on the specific cold test bench to evaluate friction losses.</div></div>

<div class="htmlview paragraph">This paper presents the numerical simulation method to predict the deactivation process of three-way catalytic converters.</div> <div class="htmlview paragraph">Three-way catalytic converter's deactivation typically results from thermal and chemical mechanisms. The major factor of thermal deactivation is the sintering of noble metal particles, which is known to depend on the ageing temperature and the oxygen concentration in the exhaust gas. The chemical deactivation is mainly caused by the poisoning, which has two effects on the catalyst deactivation. One effect is the loss of the catalyst activity, which is expressed by reduced frequency factors of reaction rates. Another effect is the suppression of the noble metal sintering. Poison deposits prevent the noble metal particles from moving in the washcoat, assisted by the reduced thermal loading of reaction heats, which is caused by the loss of the catalyst activity. Modeling these deactivation factors, we propose the rate expression of noble metal sintering.</div> <div class="htmlview paragraph">The changing process of noble metal particle size and catalyst activity distributions with mileage is simulated by the procedure to predict the deactivation process. This procedure adopts above sintering rate expression, and the details are presented in this paper.</div> <div class="htmlview paragraph">Based on simulated results of the deactivated state inside the bench aged catalyst, which are noble metal particle size and catalyst activity distributions, thermal responses and light-off behaviors during warm-up tests are predicted. Predicted results show good agreement with the measured results.</div> <div class="htmlview paragraph">Moreover, transient conversion behaviors of the bench aged catalyst during LA#4 mode test are predicted. Predicted results lead to the conclusion that the numerical simulation method presented enables the prediction of the relative values of cumulated emissions of aged catalysts with sufficient accuracy.</div>

<div class="section abstract"><div class="htmlview paragraph">Existing multi-axle steering system designs generally use the deterministic optimization method without considering the uncertainties during the design process; therefore an actual steering movement may deviate from the ideal movement calculated by some mathematical models. In order to make design results have less sensitive to the uncertainties in the design process, some uncertainties need be taken into account at the early design stage. This paper proposes a robust optimization design method for a double front axle steering system (DFASS) of heavy trucks based on Monte Carlo method. The DFASS consists of two trapezoidal steering mechanisms (TSM) and one rocker system, and the optimization objectives of DFASS include the minimum mean value and variance of the maximum turning angle error of the TSM and rocker system. In addition, the robust optimization model includes 13 design variables which are all geometry parameters of DFASS and represented by normal distribution. Through the orthogonal experiment, we obtain the important factors affecting optimization objectives and build the response surface models of optimization objective. Based on the response surfaces, robustness design of DFASS is performed. By simulating analysis, the improved robustness of DFASS based on robust design method is approved.</div></div>

<div class="htmlview paragraph">A recently patented transducer introduces new options for controlling and monitoring mobile equipment by measuring flow pressure, and temperature. Traditional flow transducers lack the robustness, accuracy, or responsiveness to be effectively used in actual hydraulic circuits outside the laboratory environment. Pressure transducers are used, but present packaging and cost obstacles to machine designers. Temperature sensors are also available in various subsystems in mobile equipment.</div> <div class="htmlview paragraph">Accurate monitoring or control of a fluid system depends upon dynamic measurement of the flow and pressure in a system, but at the same time it is important that the monitoring apparatus is capable of measuring small variations in relatively large flow rates.</div> <div class="htmlview paragraph">A new device has been developed in a cartridge format which solves previous limitations. The cartridge mounts easily into a manifold block, and can be produced economically. Output signals are analogue voltages suitable for digital display or processing by a control unit. Robust design as well as efficient low power operation round out the packaging criteria.</div> <div class="htmlview paragraph">The cartridge is capable of measuring flow, pressure and temperature in a single unit with response fast enough to be used for feedback in circuit applications as well as for diagnostic information. This transducer is an example of how available technologies and well understood principles can be applied and packaged into a format easily adaptable to the next generation of electrohydraulic control systems and to bring the long promised benefits of electrohydraulics to users.</div>

<div class="htmlview paragraph">It was desired to optimize an existing design concept of an active engine mount technology intended for engines with controlled cylinder deactivation. Specifically, this case study addresses how this active Noise & Vibration countermeasure was optimized using techniques derived from Taguchi Robust Engineering and DFSS strategies.</div> <div class="htmlview paragraph">This paper will focus primarily on how the appropriate robust design strategy was applied including the selection of the response function, a properly sized orthogonal array for the design control factors, and a sufficient noise strategy.</div> <div class="htmlview paragraph">A discussion of the design control factors, noise factors, Design of Experiment (DOE), and post-experiment standardized signal-to-noise ratio optimization analysis of the non-linear response function will be presented.</div> <div class="htmlview paragraph">Design control parameters included passive attributes of hydraulic engine mounts, as well as active/electronic components. Noise strategy was defined using three variables; heat and load cycling aging, ambient temperature, and static preload.</div> <div class="htmlview paragraph">In addition, passive performance of the active mount was analyzed using non-dynamic response functions and checked against best practice performance requirements.</div> <div class="htmlview paragraph">Results obtained from the study have documented the process to optimize a design for variation using dynamic response function for the active behavior of the mount, and nominal-the-best Type I from Taguchi Methods for passive behavior. The optimized design is planned to be prototyped and verified by experiment.</div> <div class="htmlview paragraph">The paper documents the application of the latest thinking in the field of Robust Engineering and DFSS strategies. The methods, techniques, and process are equally applicable to other elastomer based anti-vibration devices.</div>

<div class="section abstract"><div class="htmlview paragraph">Traditionally, ground vehicle aerodynamics has been researched with highly simplified models such as the Ahmed body and the SAE model. These models established and advanced the fundamental understanding of bluff body aerodynamics and have generated a large body of published data, however, their application to the development of passenger vehicles is limited by the highly idealized nature of their geometries. To date, limited data has been openly published on aerodynamic investigations of production vehicles, most likely due to the proprietary nature of production vehicle geometry. In 2012, Heft et al. introduced the realistic generic car model ‘DrivAer’ that better represents the flow physics associated with a typical production vehicle. The introduction of the DrivAer model has led to a broad set of published data for both experimental and computational investigations and has proven itself invaluable as a correlation and calibration tool of wind tunnels, the validation of computational fluid dynamics (CFD) codes and increasing the understanding of the fundamental flow physics around passenger vehicles.</div><div class="htmlview paragraph">Automotive sales trends in the United States, published by the Bureau of Economic Analysis in 2018, indicate that sales of Pickup Trucks (PUs) and Sports Utility Vehicles (SUVs) have increased over the past 10 years and are outselling sedans at a rate just over two to one. Compared to sedans, PU and SUV body styles pose additional aerodynamic challenges due to their complex wake structures. The introduction of a realistic generic PU and SUV model as an open access tool is expected to yield benefits to the wider community, equivalent to those of the DrivAer passenger vehicle. This paper introduces the Generic Truck Utility (GTU) as a realistic, generic PU truck and interchangeable SUV model. The paper will focus on the design and development of the GTU and will present a summary of preliminary experimental results of the GTU complemented by numerical simulations using iconCFD®, an open source based CFD solver.</div></div>

<div class="section abstract"><div class="htmlview paragraph">As the automotive industry increasingly shifts toward electrification, reducing vehicle drag becomes crucial for enhancing battery range and meeting consumer expectations. Additionally, recent regulations such as WLTP can require car manufacturers to provide reliable drag data for vehicles as they are configured, as is the case in Europe. Vehicle and tire manufacturers can assess tire impacts on vehicle performance through testing. However, to improve designs, it is essential to identify which tire features influence the flow field and overall vehicle performance. Physical tests measure tire behavior under load, but isolating contact patch and tire bulge effects is difficult, as both change together. Simulation allows independent analysis of these factors—something that physical testing alone cannot achieve.</div><div class="htmlview paragraph">This paper investigates the aerodynamic impact of realistic tire deformation parameters—specifically, bulge and contact patch deformations—using PowerFLOW® from Dassault Systèmes ®, a Lattice Boltzmann Method (LBM) based CFD solution with an Immersed Boundary method (IBM) to model a deformed rotating treaded tire. The standalone tire setup used in this study was validated against experimental results in prior research. To further assess the impact of these deformations on vehicle drag, simulations were repeated using the generic automotive DrivAer model. Given the complexity of the flow features in a tire wake, the study employed a combination of analysis methodologies, including Principal Component Analysis (PCA) and a vortex tracking algorithm based on the Gamma 2 criterion and single-link hierarchical clustering.</div><div class="htmlview paragraph">The results demonstrate that bulge deformations tend to have a strong wake interaction with the vehicle ultimately affecting its drag, while contact patch deformations can show either purely local effects on the tire or a more complex mix of both local effects and wake interactions.</div></div>

<div class="htmlview paragraph">Since porosity is known to have a very significant influence on the coefficient of friction of wet friction material, a new technique was developed to determine porosity.</div> <div class="htmlview paragraph">To measure porosity, “Laserthermographie” uses the fact, that thermal properties of any friction material are specifically influenced by pores. Any increase or decrease of the pore volume will lead to a change in heat capacity, heat conductivity and apparent density of the friction material:</div> <div class="htmlview paragraph">Using a modulated energy source (laser) thermal waves are generated on a friction material surface. The “thermal response” of this surface is then detected by an infrared radiation detector.</div>

<div class="htmlview paragraph">Increasingly, product engineers must influence customer satisfaction with robust designs, as opposed to waiting for manufacturing to build quality into a product. To enable and facilitate these efforts, simulation and analysis must be used to guide the system to an improved or even optimal state versus merely a functional one. The integration of Multibody System Analysis (MSA) with Design of Experiments (DOE) creates a powerful combination of tools for thorough investigation of a specified design space, identification of the optimal system configuration, and illustration of the effects of system changes on a given output.</div> <div class="htmlview paragraph">This paper demonstrates this approach for a specific output: the vertical loads into a suspension's front strut/shock tower due to a severe pothole road event. This event is designed to test the energy management function of a suspension for severe impact events. Improper energy management leads to excessive forces transmitted to the body structure. The analysis presented in this report is an introductory example. The power of this tool to impact customer satisfaction manifests itself primarily in the analysis of the ride and handling functions of the suspension. The fundamental lesson, though, is that the design of experiments approach provides much more information than the haphazard one-factor-at-a-time experimentation.</div> <div class="htmlview paragraph">Since implementing this approach, the authors have found that every system examined behaves differently. The interactions are different, and the factors differ in the amount of their impact on each system. This will be apparent to the reader as the two strut suspensions and one SLA (short-long arm) suspension are presented. Also, the chosen component design spaces dictate the levels of each factor chosen, which impacts the contribution of each factor. Thus, it is worthwhile using this approach on all systems since each differs from the others and engineers can not necessarily generalize from one system to the next.</div>

<div class="section abstract"><div class="htmlview paragraph">Electric Vehicles (EVs) are rapidly transforming the automotive landscape, offering a cleaner and more sustainable alternative to internal combustion engine vehicles. As EV adoption grows, optimizing energy consumption becomes critical to enhancing vehicle efficiency and extending driving range. One of the most significant auxiliary loads in EVs is the climate control system, commonly referred to as HVAC (Heating, Ventilation, and Air Conditioning). HVAC systems can consume a substantial portion of the battery's energy—especially under extreme weather conditions—leading to a noticeable reduction in vehicle range.</div><div class="htmlview paragraph">This energy demand poses a challenge for EV manufacturers and users alike, as range anxiety remains a key barrier to widespread EV acceptance. Consequently, developing intelligent climate control strategies is essential to minimize HVAC power consumption without compromising passenger comfort. These strategies may include predictive thermal management, cabin pre-conditioning, zonal climate control, and integration with renewable energy sources. By implementing such energy-efficient solutions, EVs can achieve better range performance, improved user satisfaction, and greater environmental benefits.</div><div class="htmlview paragraph">Modern EV climate control systems increasingly rely on intelligent features such as Auto mode, which dynamically adjusts fan speed, airflow direction, and temperature settings based on real-time cabin and ambient conditions. By leveraging sensor data and adaptive control algorithms, Auto mode optimizes thermal comfort while minimizing unnecessary energy expenditure. This automated regulation plays a crucial role in reducing HVAC-related power consumption, thereby contributing to overall range improvement and enhancing system efficiency without compromising passenger comfort.</div><div class="htmlview paragraph">This study focuses on the development of three distinct Auto mode calibration levels for each set condition, designed to achieve the same cabin temperature with varying dynamic responses and energy consumption profiles. In Auto mode, the cabin temperature is regulated through intelligent control of compressor speed, blower speed, and evaporator temperature. While all Auto levels can maintain the desired setpoint, the time required to reach this temperature and the system’s responsiveness to sudden thermal loads can vary significantly. This study introduces three distinct calibration profiles, each engineered to achieve the same cabin temperature under different dynamic conditions and energy consumption levels. These profiles allow users to choose between faster thermal response or reduced power usage, effectively enabling a trade-off between immediate comfort and extended driving range</div></div>

<div class="section abstract"><div class="htmlview paragraph">This paper deals with designing methodology of centrifugal type automatic decompression system (CADS) for small gasoline engine. CADS reduce the operator’s fatigue to start the engine. When engine cranked, CADS releases combustion pressure of the engine via opening of exhaust valve momentarily during compression stroke, which drastically reduces the hand pulling force required to start the engine with recoil starter unit. A 172 cc gasoline engine, which has applications in agricultural purposes, has been used for designing and development of CADS, which has to be installed at camshaft cam gear assembly of engine. With the new developed concept operator’s hand pulling force for starting the engine has been reduced to 41 % and henceforth durability of engine starting system increased significantly. In this paper detailed design approach has been discussed of working model of CADS. Based on predicted failure modes and generated RPN values, design calculations were carried out for various geometrical parameters of sub parts of CADS like mass of centrifugal flyweight, number of coils, wire diameter, spring rate of torsion spring. PTC CREO 3.0 has been used to make rough 3 D model of assembly and further it is optimized based on calculated design values and ease of manufacturability. A testing approach also has been discussed for checking desired spring rate of torsion spring and on engine overall working mechanism of CADS.</div></div>

<div class="htmlview paragraph">Convective heat transfer coefficients were determined for thermocouple junctions oriented parallel to the gas flow for Reynolds numbers (based on wire diameter) from 163 to 17,500. Chromel-alumel wires of 0.013-0.051 in. diameter were tested in air and products of natural gas combustion at temperatures of 60, 500, and 1000 F. Transient response was used to determine the heat transfer coefficient, and all data were corrected for variation of metal specific heat and radiant heat transfer. The affect on apparent heat transfer coefficient was determined for variations in junction weld-bead size, junction length, and wire separation.</div> <div class="htmlview paragraph">An empirical equation has been derived relating Nusselt number and Reynolds number that fits 92% of the test data within ± 10%.</div>

<div class="htmlview paragraph">This paper discusses in detail how data categories, data quality and allocation procedures were defined and implemented in the USAMP LCI analysis of a generic automobile. These data-related parameters are important for all LCI analyses but are especially important for the USAMP LCI analysis of a complete automobile. Whereas most LCI analyses have been conducted on relatively simple product systems consisting of a single material made with a single manufacturing process, the USAMP product system consists of a vast, interconnected array of dissimilar materials, products and manufacturing processes coupled with complex use, maintenance and disposition life cycle stages. As a result of this complexity, data is necessarily collected from an equally wide range of potentially incompatible sources.</div> <div class="htmlview paragraph">To achieve a coherent end result, it is imperative to not only define these data-related parameters but also to define them in terms that are applicable throughout the complex life cycle of an automobile. The sections on data quality and allocation procedures are segmented into the principal components of the generic vehicle LCI model, which includes raw material acquisition (steel, aluminum, plastics), part manufacturing and vehicle assembly, use of the automobile and the final end-of-life disposition. The details in these sections illustrate the challenges encountered in applying consistent data quality requirements and allocation procedures to a complex product system.</div> <div class="htmlview paragraph">This paper is one of six SAE publications discussing the results and execution of the USCAR AMP Generic Vehicle LCI. The papers in this series are (Overview of results 982160, 982161, 982162, 982168, 982169, 982170).</div>

<div class="htmlview paragraph">Glass run-channel seals are located between DIW (Door in White) and window glass. They are designed to allow window glass to move smoothly while other two major requirements are met; (1) Provide insulation to water leakage and noise, and (2) Stabilize the window glass during glass movement, door slamming and vehicle operation.</div> <div class="htmlview paragraph">For a robust glass guidance system, it is critical to minimize the variation of seal compression force. In addition, it is desired to maintain a low seal compression force, which meets the minimum requirement for insulating water leakage/noise and stabilizing the window glass, for enhancing the durability of glass guidance system.</div> <div class="htmlview paragraph">In this paper, a robust synthesis and design concepts on the glass run-channel seal is presented. The developed concept is demonstrated with test data.</div>