Velocity Correction of Nozzle in 3/4 OpenJet Wind Tunnel

Abstract:

In this paper, numerical simulation is employed to calculate the flow field in 1∶15 wind tunnel with 3/4 openjet test section. Two measurement methods of wind speed tested at the nozzle and the chamber were adopted and a correction method of velocity data derived from wind tunnel test is proposed based on comparative analysis. Simulation results indicate that, for empty wind tunnel at the different upstream velocities, the two methods both show good agreement with test data; for wind tunnel with car model in the test section at the wind speed of different Reynolds numbers, the predicted velocity results of both two methods need to be corrected due to the blockage effect of test model on the pressure distribution around the nozzle area. The coefficient for pressure correction can effectively improve the prediction accuracy of wind speed, because it is a higherorder polynomial term depending on the upstream velocity.