Contents: Introduction to automobile aerodynamics. Some fundamentals of fluid mechanics. Performance of cars and light vans. Aerodynamic drag of passenger cars. Driving stability in side winds. Operation, safety and comfort. High performance vehicles. Commercial vehicles. Engine cooling systems. Heating, ventilation and air conditioning of motor vehicles. Wind tunnels for automobile aerodynamics. Measurement and test techniques. Numerical methods for computation of flow around road vehicles.

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Aerodynamics of Road Vehicles

Hybrid LES/RANS methods for the simulation of turbulent flows

The first author acknowledges the partial support by a National Science Foundation Graduate Fellowship and the partial support by a National Defense Science and Engineering Graduate Fellowship. The second and third authors acknowledge the partial support by the Motor Sports Division of the Toyota Motor Corporation under Agreement Number 48737, and the partial support by a research grant from the Academic Excellence Alliance program between King Abdullah University of Science and Technology (KAUST) and Stanford University. All authors also acknowledge the constructive comments received during the review process.

Efficient non-linear model reduction via a least-squares Petrov–Galerkin projection and compressive tensor approximations

The GNAT method for nonlinear model reduction: Effective implementation and application to computational fluid dynamics and turbulent flows

Turbulence model development for aerodynamic applications has for many years concentrated on improving the capabilities of CFD methods for separation prediction. Validation studies of turbulence models in the ‘80th have clearly shown that most turbulence models were not capable of predicting the development of turbulent boundary layers under adverse pressure gradient conditions. Based on that observation, new models were developed to specifically meet this challenge, resulting in a series of models capable of capturing boundary layer separation in good agreement with experimental data (Johnson and King 1984, Menter 1993, Spalart and Allmaras 1994).

Adaptation of Eddy-Viscosity Turbulence Models to Unsteady Separated Flow Behind Vehicles

For a basic ground vehicle type of bluff body, the time averaged wake structure is analysed. At a model length based reynolds number of 4.29 million, detailed pressure measurements, wake survey and force measurements were done in a wind tunnel. Some flow visualisation results were also obtained. Geometric parameter varied was base slant angle. A drag breakdown revealed that almost 85% of body drag is pressure drag. Most of this drag is generated at the rear end. Wake flow exhibits a triple deck system of horseshoe vortices. Strength, existence and merging of these vortices depend upon the base slant angle. Characteristic features of the wake flow for the low drag and high drag configurations is described. Relevance of these phenomena to real ground vehicle flow is addressed.

G. Ramm

Papers

Some salient features of the time - averaged ground vehicle wake