INFLUENCE OF CONTRACTION SHAPE ON THE FLOW QUALITY IN WIND TUNNEL TEST SECTION
<p style="text-align: justify;">Contraction is a part of a wind tunnel that has the greatest impact on the air flow quality in the test section. The constriction ratio, the cross section shape, the length and wall shape are constructive parameters that influence the uniformity of the flow, the flow turbulence intensity, the flow rotation angularity, the appearance of the flow separation and the thickness of the fluid flow boundary layer in the test section. For this reason, it is very<br />important to choose the optimal combination of the mentioned contraction design parameters. In this paper, an analysis of five different contours of the contraction wall was performed for the square outlet cross-section Ao=0.64 m2, the constriction ratio CR=4 and the contraction length L=1.88 m. With the computer code of Flow Simulation, 25 numerical simulations were performed and the obtained results were analyzed.</p>