Extended Applications of PSP and TSP

This chapter describes extended applications of PSP and TSP in other problems. Based on the mass transfer analogy, PSP as an oxygen sensor provides a global method to determine the film cooling effectiveness on various gas turbines surfaces such as flat plate, blade surface, blade tip, endwall, and leading and trailing edges. Unsteady film cooling measurements with fast PSP are described. Skin friction is related to surface temperature, scalar concentration, and surface pressure, and the exact relations between skin friction and these quantities can be derived from the fundamental equations in fluid mechanics. Therefore, a skin friction field can be extracted as an inverse problem from surface flow visualizations using TSP and PSP. Extraction of skin friction fields from TSP and PSP visualizations is demonstrated in three examples: water flow over a circular cylinder, dual colliding impinging nitrogen jets, and square junction flow. PSP can be adapted as a planar oxygen optode for global measurement of free oxygen distribution across the sediment-water interface, as demonstrated in two examples. Other applications include pressure-sensitive particles for simultaneous pressure and velocity measurements, oxygen distributions in fuel cells, and thermographic phosphor to measure surface temperature fields on a piston and a sidewall in a cylinder of an engine.