Analyses of flow field structures around linear-type aerospike nozzles using LIF and PSP

Aerospike nozzles have been expected as a candidate for an engine of reusable Space Shuttles to respond to growing demand for rocket-launching at the lower cost. In this study, the flow field structures in any cross sections around the linear-type aerospike nozzle are visualized and analyzed, using laser induced fluorescence (LIF) of NO seeded in the carrier gas N/sub 2/. Since the flow field structure is affected mainly by the pressure ratio (P/sub s//P/sub a/), the linear-type aerospike nozzle is set inside the vacuum chamber to carry out the experiments in the wide range of pressure ratios from 75 to 250. Flow fields are visualized in several cross-sections, demonstrating the complicated three-dimensional flow field structures. Pressure sensitive paint (PSP) of PtTFPP bound by poly(TMSP) is also applied successfully to measurement of the complicated pressure distribution on the spike surface.