Model size influence on its aerodynamic coefficients in a low speed wind tunnel

A flow with/without a model in the test section of a low-speed wind tunnel is examined. The problem is solved for the two-dimensional case with the help of the ANSYS code. The mathematical model of the flow includes the Reynolds equations with the SST-turbulence model. The calculation region consists of the fore-chamber, nozzle, test section, and diffuser. The computation is made on structured grids and the number of calculation meshes is about 110000. Since the boundary-value problems for a model in a free stream and in a wind tunnel flow are distinct, in general the flow parameters on the model surface and aerodynamic characteristics of the model are not the same for these two flows. The influence of the size of the model on its aerodynamic coefficients is illustrated by the example of the flow around the NASA 0012 profile inside the free flow and in the test section of a low speed wind tunnel.