Experiment on thrust adjustment characteristics of fluidic nozzle throat

A cold-flow test research of fluidic nozzle throat was performed using the gas and water as secondary flow medium to study the thrust adjustment characteristics of fluidic nozzle throat of solid rocket motor. The influence of different secondary flow mediums, injection ways and injection mass flow rates on thrust response time, choke performance, thrust angle and thrust efficiency were studied. The experimental results show that the thrust response time is shorter using liquid secondary flow; the choke performance and thrust angle are related to injection positions and injection angle of secondary flow, and increase with increasing mass flow rate ratio; under the same mass flow rate ratio, thrust performance by using gaseous secondary flow is better than that by liquid secondary flow; but liquid secondary flow needs smaller pressure ratio and larger mass flow rate ratio adjustment range when the same mass flow rate ratio is given.