Numerical analysis of aerospike nozzle flowfield using tvd finite volume method

摘要

Aerospike nozzle engines are considered as a candidate for the next generation of propulsion system for reusable launch vehicles because of the possibility of improving performance. An numerical investigation of aerospike nozzles were performed solving the Navier-Stoke equations at various ambient pressures. Turbulence is taken into account using k- epsilon model. A TVD scheme, with combination of high accuracy, good robustness and computational efficiency, is proposed for computing high-speed flow with shocks. Parameters investigated included spike length, pitch angle and secondary flow rate. Results indicated that significant performance gains result from the external freestream expansion, which self-adapts to external pressure variation, as well as the short compact design for high expansion ratios. The expansion waves, compression shocks and the separated base flow dominate the flow structures and affect the aerospike nozzle rocket engine performance. Secondary flow may eliminate the recirculating base flow region and better performance will be obtained. Critical design aspects are discussed, and performance characteristics of the designed aerospike nozzle are presented.