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Ahmed body

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Brief Description


Fig. 1: Ahmed model. Dimensions are in mm (Fig. from [4])

Description of the test case: The Ahmed body (Fig. 1) was first defined and its characteristics described in the experimental work of Ahmed [1]. Two configurations with slant angles of 25°and 35°are considered as a test case. For this configurations detailed LDA Measurements have been performed by Becker, Lienhart and Stoots [2,3] in the LSTM low-speed wind-tunnel with a cross-section of 1.87x1.4 m2 (width x height) with a bulk velocity of 40 m/s. The test-section of the wind-tunnel was 3/4 open (only ground plate present). The distance between the body and the plate representing the ground is 50 mm. In the experiment perform by the Ahmed [1], flow velocity was taken 60 m/s, Reynolds number was 4.29 million based on model length.

A detailed test case description can be found here


[1] S.R. Ahmed, G. Ramm, Some Salient Features of the Time-Averaged Ground Vehicle Wake, SAE-Paper 840300, 1984

[2] H. Lienhart, S. Becker, Flow and Turbulence Structure in the Wake of a Simplified Car Model, SAE 2003 World Congress, SAE Paper 2003-01-0656, Detroit, Michigan, USA, 2003

[3] H. Lienhart, C. Stoots, S. Becker, Flow and Turbulence Structures in the Wake of a Simplified Car Model (Ahmed Model), DGLR Fach Symp. der AG STAB, Stuttgart University, 15-17 Nov., 2000

[4] C. Hinterberger, M. García-Villalba, W. Rodi, Large Eddy Simulation of flow around the Ahmed body. In "Lecture Notes in Applied and Computational Mechanics / The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains", R. McCallen, F. Browand, J. Ross (Eds.), Springer Verlag, ISBN: 3-540-22088-7, 2004

[5] S. Krajnovic, L. Davidson, Large eddy simulation of the flow around a simplified car model, SAE 2004 World Congress, SAE Paper 2004-01-0227, Detroit, Michigan, USA, 2004

[6] M. Minguez, R. Pasquetti, E. Serre, High-order large-eddy simulation of flow over the “Ahmed body” car model, Phys. Fluids, 20, 9, 2008

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