Research on Sealed Chamber Wall Effects in an Extremely Low Wind Speed Calibration Facility

The side wall interference and disturbance reflection from the front end wall of a sealed chamber in an extremely low wind speed calibration facility operated by driving the probe in motion might have influence on the flow field inside the chamber,thus affecting the calibration accuracy.The moving overlapping grid technique is used in solving the URANS equations simulating the flow field in the chamber to investigate the effects of side-wall interference and the disturbance wave reflection from the front(upstream)end wall on the interior flow field and calibration.The flow fields in the cases with and without side walls are computed and compared.For the front end wall reflection of the strut rod disturbance,the boundary conditions with and without front end wall are used respectively in computing the flow field in the chamber,and the computed flow fields in the two cases are compared at several instants,respectively.The computed results show that the effects of velocity deviations caused by the wall interfere