Aerospike nozzle contour design and its performance validation

A simplified design and optimization method of aerospike nozzle contour and the results of tests and numerical simulation of aerospike nozzles are presented. The primary nozzle contour is approximated by two circular arcs and a parabola; the plug contour is approximated by a parabola and a third-order polynomial. The maximum total impulse from sea level to design altitude is adopted as objective to optimize the aerospike nozzle contour. Hot-firing tests were performed on two gaseous H₂/gaseous O₂ (GH ₂/GO²) linear aerospike nozzle engines designed by method proposed in the paper. Data measured in the tests and data analyses are presented. A thrust computation model for GH₂/GO₂ aerospike nozzle was developed to study aerospike nozzle aerodynamics simulation with finite-rate chemical kinetics. The computational methodology was built on 7-species, 8-reaction and 6-species, 8-reaction finite-rate chemical models for flowfield of plug and primary nozzle combustion process and a simplified base pressure prediction model for base thrust computation. It was shown that experimental aerospike nozzles have good altitude compensability. High nozzle thrust efficiencies were yielded in the tests. Two aeropike nozzle efficiencies reached from 92%∼98% at different altitudes from sea level to near design point. The proposed contour design method and thrust computation model was validated by the hot-firing tests. Thrust efficiencies predicted by the model were in good agreements with experimental data. Copyright IAF/IAA. All rights reserved.