A CFD validation study for automotive aerodynamics

摘要

A study was conducted using Ford's nine standard CFD calibration models are described in SAE paper 940323. The models are identical from the B-pillar forward but have different back end configurations. These models were created for the purpose of evaluating the effect of back end geometry variations on aerodynamic lift and drag. Detailed experimental data are available for each model in the form of surface pressure data, surface flow visualization, and wake flow field measurements in addition to aerodynamic lift and drag values. This data is extremely useful in analyzing the accuracy of the numerical simulations. The objective of this study was to determine the capability of a digital physics-based commercial CFD code, PowerFLOW to accurately simulate the physics of the flow field around the car-like benchmark shapes. Accuracy of the code was evaluated based on comparisons of predicted lift, drag, surface pressures, surface flow and general flow field characteristics to the experimental data. The experimental data was, in general, closely approximated by the simulation predictions. Some deviations from the experimental data were noted and are discussed. It was concluded that DIGITAL PHYSICS based CFD code such as PowerFLOW demonstrated potential to be a useful alternative to conventional RANS CFD methodologies for vehicle aerodynamic calculations.