EFFECT OF THE FLOW FIELD DEFORMATION IN A WIND TUNNEL ON AERODYNAMIC COEFFICIENTS

The quality of the flow field is highly significant wind tunnel measurements are bing made. When an air flow field is formed by a fan, the entire flow field rotates. Moreover, the flow field is deformed at the bends of a wind tunnel with close circulation. Although wind tunnels are equipped with devices that eliminate these non-uniformities, in most cases the air flow field does not have ideal parameters in the test section. In order to evaluate the measured results of the model in the wind tunnel, it is necessary to characterize the deformation of the flow field. The following text describes the possible general forms of the flow field non-uniformity, and their effect on the calculation of the aerodynamic coefficients.