Studies on aerodynamic behavior and performance of aerospike nozzles

Experimental and numerical studies are carried out on a 6-cell tile-shaped aerospike nozzle, a 6-cell aerospike nozzle with round-to-rectangle primary nozzles and a 1-cell linear aerospike nozzle. Good altitude compensation capacities and high efficiencies are obtained in the tests. The efficiencies of 6-cell tile-shaped aerospike nozzle and 1-cell linear aerospike nozzle at design altitude approach to 100%, and that of 6-cell aerospike nozzle with round-to-rectangle primary nozzles in the same condition is about 95% due to the imperfect cell contour and manufacturing defects. Numerical results are in good agreements with test data. The effects of ambient pressure on exhaust and then on base behavior are analyzed. The effects of variation in the amount of base bleed on performance are also examined in the tests.