Research On Measuring System Of Solid Rocket Motor With High-speed Rotation

Solid rocket motor is propeller of hybrid base-bleed-rocket extended-range projectile. Itfollows projectile with high-speed rotation in the working state. Comparing with stationarystate, high-speed rotation make performance of the trajectory and key operating parameterschange a lot. In order to measure the parameter of motor with high-speed rotation,measurement system for motor with high-speed rotation is developed. It can measure thrustforce, combustion chamber pressure and temperature. In this paper, motor’s measuring systemconsists of test bed and it’s measurement and control system.The general mechanical structure arrangement of electric spindle directly driving thevertical spindle is applied in the test bed, which solved the problem that the thrust valuemeasurement accuracy reduced due to the friction in measurement channels of the transfermode in the domestic existing test bed.The test bed mainly contains spindle system, powertransmission system, supporting system, ignition system, and thrust calibration system. Thespindle system has a vertical structure, as well as a support of hydraulic bearings and thrustbearings, thus solves the problems that the existing test bed unable to achieve high-speedrotation due to the utilization of ordinary bearing. The power transmission system achieveshigh rotation speed and continuously variable transmission of the test bed through directlydriven by the electric spindle. In the supporting system, high-precision ball slide linearbearings, which cause lower friction and ensure measurement accuracy of the thrust value, aremounted on a thrust measurement channels. The measurement of pressure and temperature inthe motor combustion chamber is completed by the test instrument, which is mounted on theend of the spindle. After the measurement, data will be read by dedicated reading device.Ignition system achieves instantly rebounding after hit through the hit mechanism. The testbed is mainly used for high-speed motor thrust test, in which the thrust is always impact force.The impact force can reduce the accuracy of the thrust measurement sensor. To solve theabove problem, the thrust calibration system is designed in this paper to calibrate for thethrust measurement sensors before each test to ensure the test accuracy.The power mechanism of thrust calibration system contains bidirectional servo hydrauliccylinder and servo valve. The mathematical model of thrust calibration system is built, its numerical simulation is developed. Simulation result shows that the system has a gooddynamic performance and can calibrate the thrust transducer.According to virtual instrument technology, measurement and control system for motoris built with test bed. The maximum speed of measuring system can reach20,000r/min. Itprovides a technology platform for high-speed testing of motor’s performance parameters.Meanwhile, the equipment for test of motor with high-speed rotation has theoreticalsignificance and application value in engineering.