Design and validation of a reconfigurable polysonic wind tunnel

A new polysonic wind tunnel has been designed and constructed at Saint Louis University. The flow paths and flow conditioning needs were designed by PhD students and the structural design and manufacturing were accomplished by local pressure vessel and manufacturing firms. Starting with a set of two 25 hp air compressors, an air filter and dryer system with an operating pressure range between 100-200 psia, and a 14 m3 storage tank, the total cost for additional components and labor was on the order of $750,000, where design and installation was completed in approximately 18 months. The facility is uniquely reconfigurable to accommodate straight and curved flow paths, with existing configurations supporting a supersonic shock wave-boundary layer interaction study in a rectangular channel and another study of a transonic linear cascade of high-pressure turbine airfoils. The design process and resulting components are described herein, and include how to improve supersonic nozzle design by adjusting for displacement thickness growth as well as how to diagnose and correct choked flow conditions which existed in the first iteration of the flow path circuit. Results also include a sample schlieren image of a normal shock wave-boundary layer interaction and airfoil static pressure distributions and total pressure ratio across the turbine showing successful configuration implementations. © 2021 IOP Publishing Ltd