Experimental study on Ahmed's body drag coefficient for different yaw angles

We present experiments conducted in a wind tunnel to characterize yaw angle effects on the drag force acting on the Ahmed body with slant angle of 25 degrees. The main contribution of this experimental work is to create a reliable database of drag coefficients under yawed conditions. For zero yaw angle, we find a small variation in the drag coefficient, C-D, for Reynolds number in the range 3 x 10(5) - 30 x 10(5), resulting in the known tendency of a drag coefficient decrement as the Reynolds number increases. This trend is in agreement with other experimental works but is 30% greater than the usual C-D (Re) function. Secondly, the drag coefficient increases significantly with an increment in the yaw angle at a constant Reynolds number. Three distinctive regions for the drag coefficient as a function of the yaw angles are established from the experimental results: the drag coefficient increases for 0 degrees less than or similar to beta less than or similar to 60 degrees, remains constant in the range 60 degrees less than or similar to beta less than or similar to 75 degrees and finally, the drag coefficient grows again until beta = 90 degrees. (C) 2016 Elsevier Ltd. All rights reserved.