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The high performance brake systems of today are usually in a delicate balance - walking the fine line between being overpowered by some of the most potent powertrains, some of the grippiest tires, and some of the most demanding race tracks that the automotive world has ever seen - and saddling the vehicle with excess kilograms of unsprung mass with oversized brakes, forcing significant compromises in drivability with oversized tires and wheels. Brake system design for high performance vehicles has often relied on a very deep understanding of friction material performance (friction, wear, and compressibility) in race track conditions, with sufficient knowledge to enable this razor’s edge design.

The piston temperature has to be carefully controlled to achieve effective and efficient thermal management in the internal combustion engines. One of the common methods to cool piston is by injecting oil from the crankcase underside to the piston under-crown area. In the present study, a novel 3-D multiphase thermal-fluid coupled model was developed using the commercial CFD software SimericsMP+ to study the piston cooling using the oil jet. In this model, an algorithm was proposed to couple the fluid and solid computation domain to account for the different timescale of heat transfer in the fluid and solid due to the high thermal inertia of the solid piston. The heat transfer coefficient (HTC) and reference temperature were mapped to the piston top surface and the liner temperature distribution was also used as the boundary condition. The temperature-dependent material properties, piston motion, and thermal contact resistance between the ring and piston were also accounted for.

The General Motors Aero Lab’s Full-Scale Wind Tunnel Facility, which came into operation in August of 1980[1], has undergone the significant upgrade of installing a state-of-the-art moving ground plane system. After almost four decades of continuous use the full-scale wind tunnel also received some significant maintenance to other areas, including a new heat exchanger, main fan overhaul, and replacement of the test section acoustic treatment. A 5-belt system was installed along with an integrated vehicle lift system. The center belt measures 8.5m long and can accommodate two belt widths of 1100mm and 950mm. Flow quality and other wind tunnel performance parameters were maintained to prior specifications which are on par with the latest industry standards [2]. The new 5-belt rolling road system maintains GM’s industry leading vehicle aerodynamic development and the improved acoustic panels ensure GM continues to develop vehicles with leading class acoustics.

The paper presents the main results of a study on the simulation of energy efficient management of on-board electric and thermal systems for a medium-size passenger vehicle featuring a parallel-hybrid diesel powertrain with a high-voltage belt alternator starter. A set of advanced technologies has been considered on the basis of very aggressive fuel economy targets: base-engine downsizing and friction reduction, combustion optimization, active thermal management, enhanced aftertreatment and downspeeding. Mild-hybridization has also been added with the goal of supporting the downsized/downspeeded engine performance, performing energy recuperation during coasting phases and enabling smooth stop/start and acceleration. The simulation has implemented a dynamic response to the required velocity and manual gear shift profiles in order to reproduce real-driver behavior and has actuated an automatic power split between the Internal Combustion Engine (ICE) and the Electric Machine (EM).

Designing power electronics to operate in harsh vehicle environments while meeting packaging requirements such as mass, volume, and power density, creates several challenges for their mechanical design. In this work, we concentrate on the power inverter module (PIM) which converts high voltage (HV) DC voltage power from the HV battery to AC power to drive the motor. The PIM main components are the power module, gate drive and the bulk capacitor. The sizing and selection of the bulk capacitor and power module depend on performance criteria and drive profiles in addition to operating temperatures. In this work, we share the main challenges of packaging components within the inverter. We then discuss best practices to ensure a robust mechanical design which meets inverter durability and reliability targets for an electric vehicle application. The main challenges discussed are bulk capacitor thermals, sealing, and Silicon Carbide (SiC) packaging.

Hybrid electric vehicles and battery electric vehicles (BEV) use power electronics (PE) devices to convert between high voltage DC power of the battery and other formats of power. These PE components requires operation within certain temperature range, otherwise, overheating causes component as well as vehicle performance degradation. Therefore, a thermal management system is required for PE components. This paper focuses on the design and development of such a PE components thermal control system. The proposed control system is a distributed thermal control system in which all the PE components are placed in series within one cooling loop. The advantage of the proposed control system is its reduced system complexity, energy efficiency and flexibility to add future PE components. In addition, electric control unit (ECU) are utilized so that complex control algorithms can be implemented.

This study brings to forefront the analysis capability of CFD for the oil-cooling of an Electric-Motor (E-Motor) powering an automobile. With the rapid increase in electrically powered vehicle, there is an increasing need in the CFD modeling community to perform virtual simulations of the E-Motors to determine the viability of the designs and their performance capabilities. The thermal predictions are extremely vital as they have tremendous impact on the design, spacing and sizes of these motors. In this paper, with the Simerics, Inc. software, Simerics-MP+®, a complete three dimensional CFD with conjugate heat transfer CHT model of an Electric Motor, including all the important parts like the windings, rotor and stator laminate, endrings etc. is created. The multiphase Volume of Fluid (VOF) approach is used to model the oil flow inside this motor.

Battery Electric Vehicles (BEVs) are becoming more competitive day by day to achieve maximum peak power and energy requirement. This poses challenges to the design of Thermal Interface Material (TIM) which maintains the cell temperature and ensure retention of cell and prevent electrolyte leak under different crash loads. TIM can be in the form of adhesives, gels, gap fillers. In this paper, TIM is considered as structural, and requires design balance with respect to thermal and mechanical requirements. Improving structural strength of TIM will have negative impact on its thermal conductivity; hence due care needs to be taken to determine optimal strength that meets both structural and thermal performance. During various crash conditions, due to large inertial force of cell and module assembly, TIM is undertaking significant loads on tensile and shear directions. LS-DYNA® is used as simulation solver for performing crash loading conditions and evaluate structural integrity of TIM.