Effect of Vortex Generator to Flow Field Quality in 3/4 Open Jet Automotive Wind Tunnel

Abstract:

Computational fluid dynamics (CFD) method was applied to studying the vortex generator effects toward 3/4 open jet automotive wind tunnel. Three vortex generators with varied plate numbers were studied separately. Firstly, the steady Reynolds Averaged Navier Stokes(RANS) method was adopted to get the steady characteristics of the flow field. Then the large eddy simulation (LES) method was used to get the unsteady characteristics of the flow field. The corresponding tests were carried out to validate the simulation methods. A comparison of the simulation results show that with the vortex generators especially the generator with three plates, the uniformity inside the flow field increases. The test section range with high speed flow is enlarged. The static pressure gradient in the axial direction is reduced and the turbulence intensity inside test section and prism layer is reduced, too. The length of test section with low turbulence intensity is extended. The turbulence energy inside flow is dispersed. The energy is minimized within the frequency range sensitive to the buffeting phenomenon.