The aim of the present study is to redesign three dimensional geometry of existing open circuit wind tunnel contraction. The present work achieves the recommended contraction ratio, maximum uniformity at the working section mid-plane, without separation, no Gortler vortices in the contraction, and minimizing the boundary layer thickness at entrance to the working section. Using CFD along with optimization tools can shorten the design optimization cycle time. Moreover CFD allows insight into the minute flow details which otherwise are not captured using flow bench tests. The design exploration algorithm is used to optimize the profile of the contraction in an automated manner. The optimization is based on using screening method to choose the best design set and verified by the CFD solver. The new contraction, compared to the old design contraction is confirmed using CFD. The new design is manufactured in full scale. The optimized contraction is investigated computationally and experimentally