Blockage effect induced by an airfoil model in the low-velocity wind tunnel test section

The results of computational and experimental studies of the flow around a symmetric airfoil with a relative thickness of 12% in the free stream and in a low-velocity wind tunnel with a closed test section are presented. The experiments are performed for the Reynolds number Re c = 0.7·10 6 −2·10 7 and angles of attack a = −12°÷12°. The problem is numerically solved in a 2D formulation by using the ANSYS Fluent software package. The mathematical model of the flow includes steady Reynolds equations closed by different turbulence models, including the k-ω SST model, which is a superposition of the k-ε and k-ω models. A significant effect of blockage of the wind tunnel test section with limited dimensions by the airfoil on the flow character and aerodynamic characteristics of the airfoil even if the blockage coefficient is only 5.7% is demonstrated.