Subsonic aerodynamics experimental research on gas-dynamic parameters of the flow

摘要

Subsonic wind tunnels are generally aerodynamic equipment allowing to obtain in one of their elements, namely in the experimental area where the model is placed, a uniform and stable airflow of determined speed. Wind tunnels of low subsonic speed, usually with continuous running, are plants where the air, driven by a fan, reach in the experimental area speeds up to 180 m/s (M 0,5). They look like tubes with (convergent - divergent) variable section. In our case the wind tunnel is a Prandtl type closed circuit in a horizontal plane, with a single return circuit and closed testing room. To reduce turbulence in the wind tunnel, the number of fan blades whose peripheral speed should not exceed 200 m/s should be as large as possible (which is the case of the INCAS subsonic wind tunnel with 12 blades). The present article is focused on the following topics: vertical and horizontal deflection and turbulence in the experimental area.