高速流体的近壁面高分辨粒子成像测速(PIV)和数据重构研究
The aim of this work was to understand the physical requirements as well as to developmethodology required to employ Time Resolved Digital Particle Image Velocimetry(TRDPIV) for measuring high speed, high magnification, near wall flow fields. Previousattempts to perform measurements such as this have been unsuccessful because ofboth limitations in equipment as well as proper methodology for processing of the data.This work addresses those issues and successfully demonstrates a test inside of atransonic turbine cascade as well as a high speed high magnification wall jet.From previous studies it was established that flow tracer delivery is not a trivial task in ahigh speed high back pressure environment. Any TRDPIV measurement requiresuniform spatial seeding density, but time-resolved measurements require uniformtemporal seeding density as well. To this end, a high pressure particle generator wasdeveloped. This advancement enhanced current capability beyond what was previouslyattainable. Unfortunately, this was not sufficient to resolve the issue of seeding alltogether, and an advanced data reconstruction methodology was developed toreconstruct areas of the flow field that where lost do to inhomogeneous seeding. Thisreconstruction methodology, based on Proper Orthogonal Decomposition (POD), hasbeen shown to produce errors in corrected velocities below tradition spatial techniquesalone. The combination of both particle generator and reconstruction methodology wasinstrumental for successfully acquiring TRDPIV measurements in a high speed highpressure environment such as a transonic wind tunnel facility.This work also investigates the development of a turbulent wall jet.