Measurement of Axial-Direction Fuel Regression Rate of Swirling-Oxidizer-Flow-Type Hybrid Rocket Engines

Abstract

The axial-direction fuel regression rates of the swirling-oxidizer-flow-type hybrid rocket engine were mesurred using PP fuel grains under the experimental conditions; grain length of 600 mm, intermediate oxygen mass flux Goitm up to about 120 kg/(m 2 ･s), combustion chamber pressure from 1 to 3MPa and burning time up to about 25 s. The experiments showed that the relation between the axial-direction fuel regression rate, l , and Goitm was expressed by a conventional hybrid regression rate formula such as ∝ l G n oitm. Although l was much faster than the timeaveraged local fuel regression rates, the nth power on Goitm for l was almost equal to that for time-averaged local fuel regression rates at the grain leading edge. l was able to be predicted using the time-averaged local fuel regression rate after burn-out and circumferentially averaged wedge angle at the grain leading edge.