Abstract: In order to obtain better off-design performance of turbocharged solid propellant ramjet(TSPR)，a control plan was proposed for off-design in which the conversion speed of the turbocharger was held constant，the air residual fraction of combustor was held constant as well. The performance model of off-design was established by analyzing the working process of TSPR. Setting the design point (22km，Ma3.64)，the off-design performance of TSPR at different altitudes such as 0km，5km，10km and 15km was calculated and analyzed .The results show that under the control plan mentioned above，the TSPR has wider range of work and better off-design performance with a strong thrust regulation and stable specific impulse. The maximum thrust is about 3 times the minimum thrust，and the maximum specific impulse is over 800s. At the off-design point(10km，Ma2.5)，by adjusting the rotational speed，the thrust adjustment ratio could reach 1.55 and the stable specific impulse performance can be obtained. Moreover，it is effective to improve the performance of TSPR by increasing conversion speed，enhancing flight speed and raising the ratio of fuel-rich gas flow and the gas flow driving turbine.

Key words: Turbocharged solid propellant ramjet；Performance of off-design point；Conversion speed；Air residual fraction；Control plan

摘要： 为了得到优良的涡轮增压固冲发动机(TSPR)的非设计点性能，提出了等换算转速、等余气系数的调节规律，通过确定TSPR非设计点共同工作过程，建立了TSPR非设计点性能模型。以高空高速(22km，Ma3.64)为设计点，计算和分析了0km，5km，10km，15km高度下TSPR的非设计点性能。结果显示:当采用等换算转速和等余气系数的调节规律时，TSPR非设计点工作范围宽广，具有良好的非设计点性能，最大推力是最小推力的3倍左右，最大比冲超过800s；在(10km，Ma2.5)的非设计点，通过调节转速，可以获得1.55倍的推力调节比和稳定的比冲性能；最后得出:提高转速，增加飞行速度，提高富燃流量驱涡流量比是增强TSPR性能的有效途径。

关键词: 涡轮增压固冲发动机；非设计点性能；换算转速；余气系数；调节规律