Flow Field and Performance Analysis of Aerospike Nozzles with Simplified Clustered Modules

Abstract

The fundamental characteristics of simplified clustered aerospike nozzles are analyzed by the computational fluid dynamics approach. Several types of aerospike nozzles, having 6, 12 and 24 inner nozzle modules with the same area ratio and total flow rate, are examined. The interactions of the exhaust flows from the neighboring modules create shock waves, which produce high-pressure regions on the nozzle surface. The base regions of the cluster-type aerospike nozzles are not influenced by the clustering of the modules and show features similar to axisymmetric-type aerospike nozzles. The base pressure is nearly equal to the environmental pressure when the pressure ratio is low and suddenly attains a constant pressure when the pressure ratio is high. The computed results show that the number of modules influence the thrust performance, and the major reason for the decrease in thrust performance with a smaller number of modules is due to thrust loss in the ramp region.