An aerospike nozzle has been expected as a candidate for an engine of reusable space shuttle to respond to growing demand for rocket-launching and its cost reduction. In this study, the flow field around a linear-type aerospike nozzle with sidewalls and the one without sidewalls are compared to confirm the effect of the sidewalls experimentally. Laser induced fluorescence (LIF) of nitrogen monoxide seeded in the carrier gas of nitrogen is used to visualize and analyze flow fields around the nozzles. Pressure sensitive paint (PSP) of PtTFPP dispersed in poly-IBM-co-TFEM is also applied to measurement of pressure distribution on the nozzle surfaces. The nozzles are set into a vacuum chamber to achieve larger pressure ratios (source pressure in a reservoir divided by ambient pressure in the vacuum chamber) because jet structures are affected mainly by pressure ratios. The visualized images by NO-LIF and pressure distribution on the nozzle surfaces measured by PSP clarify that the sidewalls work effectively for the thrust.

View full abstract