某型喷口加力调节器减压比特性改进设计

为解决某型喷口加力调节器在配装发动机使用过程中存在的涡轮落压比偏离设计值问题，对一维定常可压缩拉瓦尔喷管的气体流动状态进行了理论分析计算，从涡轮落压比的连续性工作要求分析了拉瓦尔喷管正常工作的使用条件，提出了空气减压器二级减压拉瓦尔喷管扩张段流道形状的改进设计方法，并通过了发动机试验验证，结果表明:空气减压器只有在超临界状态工作，并且激波位置在测压点位置后面时，才能保证减压比仅与针塞位置有关，与进气压力大小无关；进气压力较低时，激波位置离测压点较近，会造成减压比相对稳定状态存在偏差；增大喉道面积，可使得相同进气条件下，激波位置后移，远离测压点，有利于提高减压比的稳定性，增大后端角度会导致激波位置前移，不利于减压比的稳定。 

Improved design of pressure reduction ratio characteristics of a nozzle afterburner regulator

In order to solve the problem that the turbine drop pressure ratio deviates from the design value in the use of a nozzle afterburner regulator with an engine，the gas flow state of one-dimensional steady compressible Laval nozzle was theoretically analyzed and calculated，and the service conditions for the normal operation of Laval nozzle were analyzed according to the continuous working requirements of turbine drop pressure ratio；an improved design method for the secondary decompression Laval nozzle air pressure reducer expansion groove shape was proposed，and the engine test was conducted.The results showed that when the air pressure reducer only worked in supercritical state，and the shock wave was positioned behind the pressure measuring point location，it could ensure that relief was only associated with the position of pin plug，but had nothing to do with the inlet pressure.When the inlet pressure was low，the shock wave position was close to the pressure measuring point，which caused the deviation of the decompression ratio in the relative stable state.Increasing the throat area can make the shock position move backward and away from the pressure measuring point under the same inlet condition，which is conducive to improving the stability of the decompression ratio.Increasing the angle of the back end can make the shock position move forward，which is not conducive to the stability of the decompression ratio.