Refurbishment and Testing Techniques in a Transonic Ludwieg Tunnel

Abstract

Although cryogenic wind tunnels are typically used in industry for transonic testing, Ludwieg tunnels with high charge tube pressures can also produce unit Reynolds numbers high enough to match in-flight conditions. A brief timeline of transonic Ludwieg tunnel development is presented that shows how it was nearly selected for full-scale construction to compliment the National Transonic Facility. Having recently been refurbished, an overview of the unique high Reynolds number facility at UT Arlington is presented. Currently, experiments with the facility have been conducted using a combination of porous and solid walls with a half-span NACA 0012 model. Surface flow visualization techniques are discussed for this high Reynolds number, short duration facility. Future development efforts are presented to keep the facility suitable for current transonic testing topics. Nomenclature AOA Angle of attack M Mach number p p Plenum chamber static pressure p s Test section static pressure p t Charge tube stagnation pressure SFV Surface flow visualization SSV Sliding sleeve valve