A CFD and Experimental Study of an Ahmed Reference Model

Laser Doppler anemometry (LDA) data and a 3D Fluent computational fluid dynamics (CFD) solution are presented from a 1044mm length Ahmed (1) reference model. LDA velocity measurements are taken from a transverse plane one model length downstream at a freestream speed of 25m/s with a moving ground plane, and are compared to the CFD model. Comparisons were also made between the current computation and a previous study employing a different turbulence model. In addition, 6 component force data was recorded during the experiment and comparisons are made between the current CFD model and current and previous experimental work. Comparisons show the CFD model to successfully capture the main flow structures in the wake although discrepancies in the predicted vortex positions were thought in part to be caused by a model misalignment error.