The Ahmed car body is just an extremely simplified version of a car, but which nevertheless shows some of the important features a CFD code should be capable to predict, if this CFD code should be useful and suitable for the automotive industry (e.g. strong flow separation in the rear, influencing lift and drag of the model). From its origin, a R&D consortium had initially agreed to pay for windtunnel experiments on the Ahmed car body and the geometry together with the experimental data had been made available to the CFD community for benchmarking their CFD codes. You will find in literature a whole series of either aerospace or automotive or generic benchmark cases, which were and still are aimed to improve the capabilities of CFD codes by trying to accurately predict the initial experimental data. Another such automotive car model benchmark is the well known DriveAir car model from the Technical University of Munich, which was experimentally investigated by TUM, Dept. Aerodynamics, Dr. Indinger & Prof. Adams, with the support by BMW and Audi. The DriveAir car with its more than 24 different geometry variations looks already very similar to a contemporary car and by that it is much more interesting, but of course computationally substantially more expensive than the prediction of the flow around the Ahmed car body. The DriveAir car geometry had been made available to other researchers as well (free of charge), so that ANSYS used this benchmark for the validation of ANSYS CFX and ANSYS Fluent as well (and other researchers with their CFD codes too).

Best regards,

Dr. Th. Frank.

thanks alot sir for your reference.

It is a generic car-type bluff body with a slant back has various angles from 0 – 40 degree. It is used as a benchmark test case for simulating the external aerodynamic flow characteristics over a car model