Comparison and optimization design methodology for open-loop subsonic wind tunnel

The present study aims to investigate the effect of the contraction profile on the flow quality such as the turbulent intensity, flow uniformity and pressure compared to baseline case (existing one). Primarily, losses of every wind tunnel part should be calculated. Hence, the total pressure losses of the whole wind tunnel circuit can be determined and all these losses are added up. This technique is required to evaluate the required power to operate the wind tunnel. As result, this method is well-suited with both of opened and closed-circuit wind tunnels. Moreover, two different profiles of the contraction are compared to the baseline wind tunnel (existing one) using the Computational Fluid Dynamics (CFD) as a basis for the comparison and analysis of the airflow properties through the whole wind tunnel design. The necessary parameters are the flow conditions within the test section that included the velocity, turbulent intensity and flow uniformity as well as the pressure distribution. The results showed that the turbulent intensity is decreased by 29.7 % with more uniform flow inside the optimized wind tunnel, when the “eye design contraction wall” is used. The contraction profile (wall design shape) plays an important role to effect on the flow quality inside the test section. Therefore, a special attention should be given when designing the wind tunnel with a specific contraction profile.