A Modular Low-Speed Wind Tunnel With Two Test Sections and Variable Inflow Angle

A modular low-speed wind tunnel system was designed and developed. Due to the modular concept, the wind tunnel permitted open-jet operation, cascade testing or closed-circuit operation. The closed-circuit wind tunnel had two test sections, and it had a high quality test-section with variable flow angle that is particular valuable for airfoil or blade testing. Physical calibration of the wind tunnel facility validated the design rules and CFD methods used and demonstrated that these techniques can be employed successfully for future wind tunnel designs. A detailed study of the thermal behavior of the closed-circuit wind tunnel was conducted. A feedback control method based on a PI control law was developed and tested for the wind tunnel speed.