Numerical simulation and hot test investigation of plug nozzle in solid rocket motor

A clustered type of plug nozzle, with 16 unit nozzles and an area ratio of 25, and a compared bell nozzle were designed to gain the performance characteristics of plug nozzle. The thrust performances of the nozzles were evaluated with numerical simulation method. A ground hot test was done to measure the thrust performance the clustered plug nozzle. The result shows that the numerical simulation results of the flow phenomenon and thrust performance accord with the experimental results. The thrust efficient of the plug nozzle in ground reaches 92.6% and is 9.1% higher than the bell nozzle with the same area ratio and length, reflecting the altitude compensation effects of plug nozzle. However, its thrust efficient in high attitude is 5.8% lower than the compared bell nozzle.