Experimental Study of the Swirling Oxidizer Flow in HTPB/N₂O Hybrid Rocket Motor

Abstract

Effects of swirling oxidizer flow on the performance of a HTPB/N 2 O Hybrid rocket motor were studied. A hybrid propulsion laboratory has been developed, to characterize internal ballistics characteristics of swirl flow hybrid motors and to define the operating parameters, like fuel regression rate, specific impulse, and characteristics velocity and combustion efficiency. Primitive variables, like pressure, thrust, temperature, and the oxidizer mass flow rate, were logged. A modular motor with 70 mm outer diameter and variable chamber length is designed for experimental analysis. The injector module has four tangential injectors and one axial injector. Liquid nitrous oxide (N 2 O) as an oxidizer is injected at the head of combustion chamber into the motor. The feed system uses pressurized air as the pressurant. Two sets of tests have been performed. Some tests with axial and tangential oxidizer injection and a test with axial oxidizer injection were done. The test results show that the fuel grain regression rate has been improved by applying tangential oxidizer injection at the head of the motor. Besides, it was seen that combustion efficiency of motors with the swirl flow was about 10 percent more than motors with axial flow.

Thermal decomposition of N2O near 900 K studied by FTIR spectrometry: Comparison of experimental and theoretical O(3P) formation kinetics

“…1 It is also a major initial decomposition product of ADN, NH 4 N(NO 2 ) 2 . 2 N 2 O has recently become a favored oxidant used in hybrid rocket propulsion 3,4 because of its favorable properties mentioned above. Theoretically, there have been numerous studies on the nonadiabatic dissociation process since the early work of Stearn and Eyring in 1935, combining the Landau-Zener theory for the forbidden transition with Eyring's transition state theory.…”

Beeswax–EVA/Activated-Charcoal-Based Fuels for Hybrid Rockets: Thermal and Ballistic Evaluation

“…The low regression rate of solid fuel in hybrid rockets leads to low thrust-to-weight ratios compared to successful solid rockets. Several techniques have been reported to enhance the regression rate performance of solid fuel, including the addition of metal and metal hydrides [7][8][9][10][11] and the use of multi-port fuel grains [12,13], mixed hybrid fuels [14,15], wax-based fuels [16], the swirl injection method [17][18][19], protrusions [20][21][22][23][24][25], bluff-bodies [26], and cavities [27].…”

“…including the addition of metal and metal hydrides [7][8][9][10][11] and the use of multi-port fuel grains [12,13], mixed hybrid fuels [14,15], wax-based fuels [16], the swirl injection method [17][18][19], protrusions [20][21][22][23][24][25], bluff-bodies [26], and cavities [27].…”

Numerical Study on Combustion and Atomization Characteristics of Coaxial Injectors for LOX/Methane Engine

“…In recent years, the reusable launch vehicle (RLV) has become the spotlight of aerospace industry, and the LOX (liquid oxygen)/methane rocket engine is considered its appropriate power [1][2][3]. As a propellant for rocket engine, methane has many advantages such as low carbon deposition, low cost, high specific impulse, and environmental protection [4][5][6][7].…”