Performance Analysis of Aerospikes with Clustered Non-Conventional Modules

The high expansion ratio achievable with compact designs makes aerospike nozzles an attractive option for upper-stage applications. However, the design of annular aerospike nozzles poses significant challenges, particularly in managing thermal loads due to the extensive surface area exposed to intense heat flux. Adopting a modular approach can alleviate these issues by simplifying cooling circuit design, albeit at the cost of some performance loss. The present study explores multiple module geometries, from conventional bell-shaped nozzles to non-conventional configurations aimed at improving clustering efficiency while keeping satisfactory single module performance. With this scope, elliptical and banana-shaped nozzle sections are explored. A performance analysis is conducted by means of CFD simulations, comparing results with a reference truncated annular aerospike nozzle. Preliminary results show that a good coverage of the annular exit section of the internal expansion is crucial to avoid large thrust losses and that banana-shaped modules are the best compromise among the geometries investigated, yielding comparable performance with respect to the annular case.