Near wake interactions and drag increase regimes for a square-back bluff body

Abstract

The three-dimensional near wake of a square-back bluff body in ground proximity is experimentally perturbed by placing a pair of D-shaped obstacles under the body. Five obstacle widths, from 12 % to 26 % of the height of the body, are used to perform a sensitivity study of the body's pressure drag by varying the relative distance between the obstacle pair and the base. Two successive drag-sensitive regimes are identified for obstacle-to-base distances