Design and Flow Characterization of the Penn State Compressed Air Wind Tunnel

The Penn State compressed air wind tunnel (CAWT) is a closed-loop wind tunnel that can be pressurized to 34 bar (500 psi) to enable access to high Reynolds number flows. The tunnel flow circuit is contained inside a large, toroidal pressure vessel which requires the installation of an internal liner that consists of four main components, including a rapid expansion, a turbulence management section, a contraction, and a working section. The main purpose of the liner is to provide uniform, low-turbulence flow at the test section. This talk will describe the design and implementation of the CAWT turbulence management sections and the challenges associated with constructing a wind tunnel inside a pressure vessel with two access points. In addition, flow quality will be assessed inside the test section using a hot-wire anemometer to characterize the background turbulence level and a series of Pitot-static probe measurements will be used to determine flow uniformity.