Key Technical Research Of Ultrahigh-speed Gas Turbine Pump

Gas hydraulic servo systems are commonly used in thrust vector control ofhigh-power solid-fuel missiles. As one of the vital components of a gas hydraulicservo system, ultrahigh-speed gas turbine pump utilizes high-pressurehigh-temperature gas provided by gas generator to rotate the coaxial pump impellerin high-speed. At the same time, the tangentia l injection of high-speed gasconverts low-pressure hydraulic oil to high-pressure hydraulic energy. Because ofits high rotation speed (over100k rpm), small-size, light-weight, and high energyoutput, ultrahigh-speed turbine pump has become a critical part in gas hydraulicpower system and widely used in servo control systems.Ultrahigh-speed turbine pump is a critical component for energy conversion,which converts high-pressure, high-temperature gas energy into mechanical energyvia high-speed rotation of the turbine. Furthermore, ultrahigh-speed turbine canalso transform mechanical energy to high-pressure hydraulic energy through coaxia ltangentia l pump. The main aims of this thesis are assessing the aerodyna mics ofthe turbine solid-fue l gas generator and oblique incised de Laval nozzle (OILN) aswell as studying the rotor dynamics of high-speed rotating turbine. These factorsare profound ly associated with the input working condition, efficiency, and stability.The main finding of the current study are as following:The internal ballistic characteristics of gas generator. The flow modelingsimulation software FLUENT was used to simulate aerodynamics of de Lavalnozzle under different conditions. Subsequently, simulation results wereintroduced into the internal ballistic differentia l equations for the gas generator.Here I proposed analytical and computational methods for estimating the internalballistic characteristics of the gas generator under different nozzle conditions basedon statistical analyses of theoretical computation and empirical experiment data.The aerodynamics of OILN. The aerodynamic conditions of OILN are verycomplex, especia lly the airflow at the nozzle outlet, which commonly formsexpansion wave and shock wave. Canonical aerodynamics only deals with typicalde Laval nozzle, and no existing literature provide theoretical insights on OILN and the aerodynamics analyses and calculations of its complex shock waves andoverexpansion conditions. In the current study, the aerodynamics of model Xturbine pump OILN was simulated using flow modeling software FLUENT. Basedon the simulation, theoretical aerodynamics analyses and computations wereconducted, and the analytical and computational methods for OILN was proposed.Computational method for critical rotation speed (CRS) of turbine pump axialsystem and influencing factors. In order to ensure the working stability of turbinepump, it is absolute critical to prevent the system operating at speed near the CRS.The current study provided the computational method for calculating CRS, as wellas investigated the factors that affect CRS.