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Dissertation Defense – Jonathan Brooks – July 2nd 2:00pm

Committee Members:

Dr. Ashwani K. Gupta (advisor)
Dr. Eric Marineau

Dr. Mark Lewis
Dr. Pino Martin

Dr. Kenneth Yu

Dr. Bao Yang

Date/Time: July 2nd (Monday) at 2:00pm

Location: DeWalt Seminar Room (2164 Martin Hall)

Title: 

Development and Application of Mach 10 PIV in a Large Scale Wind Tunnel

Abstract:

This dissertation presents the development of particle image velocimetry (PIV) for use in a large-scale hypersonic wind tunnel to measure the turbulent boundary layer (TBL) and shock turbulent boundary layer interaction (STBLI) on a large hollow cylinder flare (HCF) test article. The main feature of this application of PIV is the novel local injector which injects seeding particles into the high-speed section of the flow. Development work began sub-scale in a Mach 3 wind tunnel where the seeding particle response was characterized and the local injectors were demonstrated. Once the measurement technique was refined, it was scaled up to hypersonic flow. High-speed local seeding particle injection has been demonstrated successfully for the first time. Based on the particle concentration distribution in the boundary layer a new phenomenon of particle biasing has been identified and characterized. PIV measurements of a Mach 10 TBL and STBLI have been performed on a large (2.4-m long, 0.23-m dia.) HCF at a freestream unit Reynolds number of 16 million per meter. These are the highest Mach number PIV measurements reported in the literature. Particles are locally injected from the leading edge of the test article and turbulent mixing dispersed the particles for a relatively uniform high concentration of particles at the measurement section 1.83-m downstream of the leading edge. The van Driest transformed mean velocity in the TBL agrees well with incompressible zero pressure gradient log law theory. Morkovin-scaled streamwise velocity fluctuations agree well with the literature for the majority of the boundary layer.