Design and optimization of variable thrust hybrid rocket motors for sounding rockets

Abstract

Besides safety and low-cost, the start/shutdown/restarting and throttling ability are the other two significant advantages of hybrid rocket motors (HRMs) compared with liquid and solid ones. In this study, a two-stage variable thrust and non-toxic 98%HP/HTPB hybrid rocket motor (VTHRM) is designed and applied in a sounding rocket, and the design parameters of the motor are analyzed and optimized. A computational program is developed to design the motor system structure, to predict the interior ballistics and the ballistic trajectory. A star grain and a wheel grain are compared. The design of experiment (DOE), variance analysis and the main effect analysis are employed to investigate the influence of the main design parameters on motor performance. The multidiscipline feasible (MDF) approach is applied to establish the optimization procedure after analyzing the system design structure matrix. A modified differential evolution algorithm is employed to maximize the load mass. The results indicate that the wheel grain could obtain a larger load mass and a lower length to diameter ratio, and that throttling markedly meliorates the motor and rocket performance. The conclusions drawn from the analysis and optimization could provide instructive guide and theoretical basis for engineering designs. sounding rocket, hybrid rocket motor, variable thrust motor, design of experiment, optimization design Citation: Rao D L, Cai G B, Zhu H, et al. Design and optimization of variable thrust hybrid rocket motors for sounding rockets.

Experimental Characterization of Combustion Instabilities in High-Mass-Flux Hybrid Rocket Engines

“…Introduction YBRID rocket engines, especially smaller ones such as those used in amateur rocketry, are generally operated at mass flux levels lower than 500 kg/s·m 2 [1]. As a general "rule of thumb" for their design, literature references typically mention values in the range of 500 to 700 kg/s·m 2 as the maximum attainable design mass flux level [2][3][4][5][6]. Although these mass flux levels are usually acceptable for small engines, in larger ones such as the 11 MN rocket of the Hybrid Propulsion Technology program [7] and the Stanford 66.7 kN Peregrine engine [6] it is very attractive (and sometimes even necessary) to operate at a higher initial mass flux, possibly in a range of 1100 to 1300 kg/s·m 2 , in order to achieve a sufficiently high volumetric efficiency.…”

A Promising Fuel for Variable Thrust Motor: HTPB Propellant with High Pressure Exponent

“…In recent years, new generation missile related technology asks for greater requirement of the burning characteristics of solid propellant. The anti-ballistic missile (ABM), surfaceto-air missile (SAM) and air-air missile (AAM) systems demand a flexible energy regulation technique of the sustained rocket motors or the attitude control motors [1][2][3][4], for purpose of elevating the flexibility and defensibility of weapons. Therefore, the energy regulation technique mentioned above has always been a challenge for variable thrust motors.…”

Uncertainty analysis and design optimization of hybrid rocket motor powered vehicle for suborbital flight

“…Therefore, an approach to the uncertainty analysis and design optimization of HRM powered vehicles is proposed in this paper, based on our former work about the conceptual design of HRM powered rockets. 8,9 The main problem in UDO is the low efficiency of the uncertainty analysis when the system design model is complicated. The approximate model technology is one of the most popular methods to solve this problem.…”