Development of Fuel Rich Gas Generator for 10 ton f Liquid Rocket Engine

Abstract

A fuel-rich gas generator of open cycle turbopump system was designed and experimentally tested for 10tonf thrust Liquid Rocket Engine with RP-1/LOx propellants. The baseline design of gas generator was determined by optimal design technique. The objective function is the specific impulse of main thrust chamber. Sensitivity analyses could evaluate the relative dependence of design variables on the objective function. As a result, the global optimization method, SA (Simulated Annealing), could yield a global optimization regardless of initial conditions. Also, an experimental study had been conducted to develop FO-F impinging type injector elements. In the design process, total mass flow rate based on the result of optimization of gas generator for 10tonf thrust engine could decide the diameter of fuel and oxidizer feed line. And five types of injector element with various impinging distances from the plate and impinging angles were configured and tested using kerosene vs. water propellant although kerosene/Lox is the propellant combination for the original liquid rocket engine. The comparisons of test results of each injector element reveals that the mixing efficiency with 45 degree of impinging angle and 6mm in impinging distance shows the best performance in droplet formation. The selected injector was used in evaluating combustion performance of gas generator in the hot fire test. And the combustion results will provide the feedback information how to modify the design variables in order to optimize performance of droplet formation in the injector. And, hot test results show a good agreement with design predictions of temperature and c* efficiency. Also the turbulence ring was found dominantly effective in enhancing the mixing of burned gas both in axial and radial direction although the stagnation pressure loss is inevitable in the chamber.