An analytical and experimental study of a hybrid rocket motor

The hybrid rocket motor is a kind of chemical propulsion system that has been recently given serious attention by various industries and research centers. The relative simplicity, safety and low cost of this motor, in comparison with other chemical propulsion motors, are the most important reasons for such interest. Moreover, throttle-ability and thrust variability on demand are additional advantages of this type of motor. In this paper, the result of an internal ballistic simulation of hybrid rocket motor in a zero-dimensional form is presented. Further to validate the code, an experimental setup was designed and manufactured. The simulation results are compared with the experimental data and good agreement is achieved. The effect of various parameters on the motor performance and on the combustion products is also investigated. It is found that increasing the oxidizer flow rate, increases the pressure and specific impulse of the motor; however, the slope of the specific impulse for the high flow rate case reduces. In addition, by increasing the combustion chamber pressure, the specific impulse is increased considerably. The initial diameter of the fuel port does not have significant effect on the pressure chamber and on the specific impulse. Addition of a percentage of an oxidizer like ammonium perchlorate to the fuel increases the specific impulse linearly.

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Numerical Investigation of a N2O/HTPB Hybrid Rocket Motor with a Dual-Vortical-Flow (DVF) Design

Journal of Mechanics ◽

10.1017/jmech.2017.3 ◽

2017 ◽

Vol 33 (6) ◽

pp. 853-862 ◽

Cited By ~ 1

Author(s):

A. Lai ◽

Y. C. Lin ◽

S. S. Wei ◽

T. H. Chou ◽

J. W. Lin ◽

...

Keyword(s):

Specific Impulse ◽

Rocket Motor ◽

Vortical Flow ◽

Reacting Flow ◽

Hybrid Rocket ◽

Rocket Motors ◽

Roll Control ◽

Hybrid Rocket Motor ◽

Fluid Properties ◽

Rocket Performance

AbstractA compact hybrid rocket motor design that incorporates a dual-vortical-flow (DVF) concept is proposed. The oxidizer (nitrous oxide, N2O) is injected circumferentially into various sections of the rocket motor, which are sectored by several solid fuel “rings” (made of hydroxyl-terminated polybutadiene, HTPB) that are installed along the central axis of the motor. The proposed configuration not only increases the residence time of the oxidizer flow, it also implies an inherent “roll control” capability of the motor. Based on a DVF motor geometry with a designed thrust level of 11.6 kN, the characteristics of the turbulent reacting flow within the motor and its rocket performance were analyzed with a comprehensive numerical model that implements both real-fluid properties and finite-rate chemistry. Data indicate that the vacuum specific impulse (Isp) of the DVF motor could reach 278 s. The result from a preliminary ground test of a lab-scale DVF hybrid rocket motor (with a designed thrust level of 3,000 N) also shows promising performance. The proposed DVF concept is expected to partly resolve the issue of scalability, which remains challenging for hybrid rocket motors development.

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Sensitivity Analysis of a Two-Phase CFD Simulation of a 1 kN Paraffin-Fueled Hybrid Rocket Motor

Energies ◽

10.3390/en14206794 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6794

Author(s):

Benoit Dequick ◽

Michel Lefebvre ◽

Patrick Hendrick

Keyword(s):

Sensitivity Analysis ◽

Cfd Simulation ◽

Rocket Motor ◽

Operating Conditions ◽

Chamber Pressure ◽

Cfd Model ◽

Hybrid Rocket ◽

Two Phase ◽

Hybrid Rocket Motor ◽

Multiple Observations

At Université Libre de Bruxelles (ULB), research was performed on a 1 kN lab-scale Hybrid Rocket Motor (the ULB-HRM). It has a single-port solid paraffin fuel grain and uses liquid N2O as an oxidizer. The first Computational Fluid Dynamics (CFD) model of the motor was developed in 2020 and improved in 2021, using ANSYS Fluent software. It is a 2D axisymmetric, two-phase steady-state Reynolds-Averaged Navier–Stokes (RANS) model, which uses the average fuel and oxidizer mass flow rates as inputs. It includes oxidizer spray droplets and entrained fuel droplets, therefore adding many additional parameters compared to a single-phase model. It must be investigated how they affect the predicted operating conditions. In this article, a sensitivity analysis is performed to determine the model’s robustness. It is demonstrated that the CFD model performs well within the boundaries of its purpose, with average deviations between predicted and experimental values of about 1% for the chamber pressure and 5% for the thrust. From the sensitivity analysis, multiple observations and conclusions are made. An important observation is that oxidizer related parameters have the highest potential impact, introducing deviations of the predicted operating chamber pressure of up to 18%, while this is only about 6% for fuel-related parameters. In general, the baseline CFD model of the ULB-HRM seems quite insensitive and it does not suffer from an excessive or abnormal sensitivity to any of the major parameters. Furthermore, the predicted operating conditions seem to respond in a logical and coherent way to changing input parameters. The model therefore seems sufficiently reliable to be used for future qualitative and quantitative predictions of the performance of the ULB-HRM.

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The rapid and low cost development of a hybrid rocket motor

10.2514/6.1993-2610 ◽

1993 ◽

Author(s):

K. SCHULZE ◽

S. MEYER

Keyword(s):

Low Cost ◽

Rocket Motor ◽

Hybrid Rocket ◽

Hybrid Rocket Motor ◽

Cost Development

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Design, construction and testing of a low‐cost hybrid rocket motor

Aircraft Engineering and Aerospace Technology ◽

10.1108/00022660310474492 ◽

2003 ◽

Vol 75 (3) ◽

pp. 262-271 ◽

Cited By ~ 7

Author(s):

Greg S. Mungas ◽

Debendra K. Das ◽

Devdatta Kulkarni

Keyword(s):

Low Cost ◽

Rocket Motor ◽

Hybrid Rocket ◽

Hybrid Rocket Motor ◽

Design Construction

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

International Journal of Aerospace Engineering ◽

10.1155/2017/3174140 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Mohammad Mahdi Heydari ◽

Nooredin Ghadiri Massoom

Keyword(s):

Specific Impulse ◽

Axial Flow ◽

Combustion Efficiency ◽

Swirl Flow ◽

Rocket Motor ◽

Outer Diameter ◽

Hybrid Rocket ◽

Feed System ◽

Regression Rate ◽

Hybrid Rocket Motor

Effects of swirling oxidizer flow on the performance of a HTPB/N2O 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 (N2O) 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.

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