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A sports car exhibits many challenges from an aerodynamic point of view: drag that limits top speed, lift - or down force - and balance that affects handling, brake cooling and insuring that the heat exchangers have enough air flowing through them under several vehicle speeds and ambient conditions. All of which must be balanced with a sports car styling and esthetic. Since this sports car applies two electric motors to drive front axle and a high-rev V6 turbo charged engine in series with a 9-speed double-clutch transmission and one electric motor to drive rear axle, additional cooling was required, yielding a total of ten air cooled-heat exchangers. It is also a challenge to introduce cooling air into the rear engine room to protect the car under severe thermal conditions. This paper focuses on the cooling and heat resistance concept.

In many engineering domains like aerospace, vehicle or engine design the analysis of flow fields, acquired from computational fluid dynamics (CFD) simulations can reveal important insights on the behavior of the simulated objects. However, the huge amount of flow data produced by each simulation complicates the data processing and limits the application of data mining and machine learning tools for the flow analysis. The paper introduces a compact streamline and feature based representation of three dimensional flow fields, in order to overcome this limitation. The compact representation defines the basis for a subsequent quantification of flow field similarities.

Wind noise consistently ranks as one of the most influential factors with respect to perceived vehicle quality. In an effort to address this issue we investigated building, solving, and analyzing a CFD (Computational Fluid Dynamics) wind noise model using LES (Large Eddy Simulation) turbulence modeling. An experimental and numerical study of the effect of an actual sunroof deflector that was in place or removed from the vehicle was conducted. The combined effects of a relatively small mesh size and time step to capture the transient flow phenomena and a large number of time steps to insure valid comparisons with typical experimental results, led to extremely large solution times and a subsequent large amount of data to analyze. While good results were obtained, the practical use of this type of analysis in a development timeline was determined to be limited.

For automotive disk brake systems, convective cooling from the rotor to surrounding airflow is an important phenomenon, impacting the rotor and friction material operating temperatures and thereby influencing friction behavior, brake pedal response, and long-term durability characteristics. Many different rotor geometries and vent patterns have been proposed in the industry, however most performance evaluation and design optimization is still done empirically through on-vehicle testing or by using a test bench such as a brake dynamometer. Existing simulations of rotor airflow performance typically do not consider the installed condition with caliper, splash shield, and knuckle [1,2], or do not combine airflow and heat transfer characteristics. This paper will present a simulation model of a disk brake assembly installed on an inertia brake dynamometer, using CFD modeling coupled with thermal loading and heat transfer analysis.

As we continue to create ever-lighter road vehicles, the challenge of balancing weight reduction and structural performance also continues. One of the key parts this occurs on is the hood, where lighter materials (e.g. aluminum) have been used. However, the aerodynamic loads, such as hood lift, are essentially unchanged and are driven by the front fascia and front grille size and styling shape. This paper outlines a combination CFD/FEA prediction method for hood deflection performance at high speeds, by using the surface pressures as boundary conditions for a FEA linear static deflection analysis. Additionally, custom post-processing methods were developed to enhance flow analysis and understanding. This enabled the modification of existing test methods to further improve accuracy to real world conditions. The application of these analytical methods and their correlation with experimental results are discussed in this paper.