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Three-dimensional numerical analysis on combustion performance and flow of hybrid rocket motor with multi-segmented grain

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Chinese Journal of Aeronautics 2020年第4期33卷 1181-1191页

作者： Hui TIAN Yu DUAN Hao ZHU School of Astronautics Beihang UniversityBeijing 100083China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of EducationBeihang UniversityBeijing 100083China

This paper presents the combustion characteristics in hybrid rocket motors with multisegmented grain through three-dimensional numerical ***-segmented grain is composed of several thin grains with two or more *** numerical model consists of Navier-Stokes equations with turbulence,solid fuel pyrolysis,chemical reactions,a fluid–solid coupling model and a regression rate *** simulations adopt 90%Hydrogen Peroxide(HP)and PolyEthylene(PE)as the propellant *** effects of the rotation,port number,fuel grain segment number and mid-chamber length on the flow field and combustion performances are *** results indicate that the multi-segmented grain configuration can strengthen the flow field,and the regression rate and combustion efficiency are *** the cases with two grain segments and three ports for example,the regression rate is increased by 32.4%-45.1%and the combustion efficiency increases by 6%-8.6%in different rotation angles.

关键词： Combustion efficiency hybrid rocket motor Multi-segmented grain Regression rate Rotation angle

Numerical analysis on combustion characteristics of hybrid rocket motor with star-tube segmented grain

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Chinese Journal of Aeronautics 2023年第12期36卷 102-112页

作者： Chengen LI Zongwei WANG Jin YANG Jinpeng JIANG Fan GONG Zhu LIU Yu SUN Science and Technology on Space Physics Laboratory Beijing 100076China

A method of star-tube combined segmented grain is proposed to improve the combustion performance of hybrid rocket *** star-tube combined segmented grain consists of a single-port star part and a single-port tube part.A mid-chamber forms between the fore-grain and the aft-grain for better mixing *** single-port feature gives hybrid rocket motor several advantages,such as simple structure,high reliability,and variable *** paper is mainly aimed at studying the combustion characteristics of hybrid rocket motor with star-tube segmented grain through three-dimensional steady *** performance of the motors with different segmented grain combinations,including fore-tube/aft-tube,fore-tube/aftstar,fore-star/aft-star and fore-star/aft-tube,is contrastively *** motor in this paper adopts polyethylene and 90%hydrogen peroxide as the *** reveal that segmented grain with different-type grain combinations could greatly change the flow field in the second half of the combustion *** of the flow field is beneficial to the mixing between the fuel and the oxidizer,and it could increase the fuel regression rate and the combustion *** turbulence effect of tube aft-grain is better than that of star *** the four segmented grain combinations,the combination of star fore-grain and tube aft-grain is the preferred method with optimal overall *** grain configuration could increase the regression rate of tube aft-grain to surpass that of star aft-grain in other ***,hybrid rocket motor with this grain configuration achieves the highest combustion efficiency.

关键词： Combustion performance Flow fields Fluid-solid coulping hybrid rocket motor Star-tube segmented grain

Numerical and experimental investigation on the effects of aft mixing chamber diaphragm in hybrid rocket motor

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Science China(Technological Sciences) 2013年第11期56卷 2721-2731页

作者： TIAN Hui LI XinTian YU NanJia CAI GuoBiao School of Astronautics Beihang University

This paper focuses on the investigation of an aft mixing chamber diaphragm in a hybrid rocket motor. Both numerical and ex- perimental researches are carried out to study its effects on the motor performances. The hybrid rocket motor with star fuel grain is utilized. The 90% hydrogen peroxide （HP） oxidizer and hydroxyl terminated polybutadiene （HTPB） based fuel are adopted as propellants. The diaphragm configuration settled in the aft mixing chamber includes four circular-holes with a uni- form circumferential distribution. For both motors with and without the diaphragm, three-dimensional numerical simulations with gaseous combustions considered are carried out to study the flow field characteristics and motor performances. The com- parison results show that the diaphragm can improve the mixing of the oxidizer and fuel. It has evident effect on increasing the motor efflciencies. Two firing experiments are conducted with full scale motors to investigate the effects of the diaphragm. The diaphragm used in the test is composed of a central steel framework and a closed thermal insulation layer. With the dia- phragm employed, the combustion efficiency increases from 93.9% to 97.34% and the specific impulse efficiency increases from 80.77% to 87.28%, which verifies the positive effect of the diaphragm. Both numerical and experimental studies indicate that the scheme of the aft mixing chamber diaphragm proposed in the paper can improve the efficiencies of the hybrid rocket motor obviously.

关键词： hybrid rocket motor diaphragm numerical simulation experimental investigation

Experimental and Theoretical Research Review of hybrid rocket motor Techniques and Applications

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Advances in Aerospace Science and Technology 2016年第3期1卷 71-82页

作者： Entidhar A. Alkuam Wissam M. Alobaidi Department of Physics and Astronomy College of Arts Letters and Sciences University of Arkansas at Little Rock Little Rock AR USA Systems Engineering Department Donaghey College of Engineering & Information Technology University of Arkansas at Little Rock Little Rock AR USA Department of Engineering Technology Donaghey College of Engineering & Information Technology University of Arkansas at Little Rock Little Rock AR USA

A hybrid rocket motor combines components from both solid fuel and liquid fuel rocket motors. The fuel itself is a solid grain, (often paraffin or hydroxyl-terminated polybutadiene, known as HTPB) while the oxidizing agent is liquid (often hydrogen peroxide or liquid oxygen). These components are combined in the fuel chamber which doubles as the combustion chamber for the hybrid motor. This review looks at the advances in techniques that have taken place in the development of these motors since 1995. Methods of testing the thrust from rocket motors and of measuring the rocket plume spectroscopically for combustion reaction products have been developed. These assessments allow researchers to more completely understand the effects of additives and physical changes in design, in terms of regression rates and thrust developed. hybrid rocket motors have been used or tested in many areas of rocketry, including tactical rockets and large launch vehicles. Several additives have shown significant improvements in regression rates and thrust, including Guanidinium azotetrazolate (GAT), and various Aluminum alloys. The most recent discoveries have come from research into nano-particle additives. The nano-particles have been shown to provide enhancements to many parameters of hybrid rocket function, and research into specific areas continues in the sub-field of nano-additives for fuel grains.

关键词： hybrid rocket motor Sounding rockets Tactical rockets Space Engines Thrust Augmentation Large Launch Boosters Fuel Additives Regression Rate

Numerical and experimental research on axial injection end-burning hybrid rocket motors with polyethylene fuel

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Chinese Journal of Aeronautics 2024年第8期37卷 91-105页

作者： Xiangyu MENG Hui TIAN Lingfei HE Jingfei GAO Xiaoting NIU Guobiao CAI School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of EducationBeijing 100816China

This study investigates the end-burning hybrid rocket motors with polyethylene fuel by the numerical simulation and *** on computational fluid dynamics,a numerical model is *** model is validated by two firing tests in this hybrid rocket motor,which uses oxygen and polyethylene as *** results show that the numerical and experimental data are in good agreement,and the error of the chamber pressure is less than 2.63%.Based on the simulation mode,the blowoff limit of the end-burning hybrid rocket motors is *** the nozzle throat diameter and the inner diameter of grain are large,it is more difficult for the hybrid rocket motor to achieve end-burning mode,i.e.,the flame spreading is prevented in the narrow *** main reason is that when the nozzle throat and the grain port are large,chamber pressure and oxidizer flow velocity are ***,the friction velocity considering the pressure and flow velocity is *** critical friction velocity is about 4.054–4.890 m/s in the hybrid rocket *** the friction velocity exceeds the critical friction velocity,the combustion mode in hybrid rocket motors changes from the flame spreading mode to the end-burning ***,the regression rate formula is obtained by fitting,which shows that the regression rate has a good correlation with combustion chamber *** critical friction velocity and regression rate formula can provide an important reference for end-burning hybrid rocket motors.

关键词： hybrid rocket motor End burning Blowoff limit Flame propagation Regression rate

Uncertainty analysis and probabilistic design optimization of hybrid rocket motors for manned lunar landing

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Science China(Technological Sciences) 2015年第7期58卷 1234-1241页

作者： ZHU Hao TIAN Hui CAI GuoBiao BAO WeiMin School of Astronautics Beihang University China Aerospace Science and Technology Corporation

To obtain a conceptual design for a hybrid rocket motor(HRM)to be used as the Ascent Propulsion System in the Apollo lunar module,the deterministic design optimization(DDO)method is applied to the HRM *** on the results of an uncertainty analysis of HRMs,an uncertainty-based design optimization(UDO)method is also adopted to improve the design *** HRM design process,which is a multidisciplinary system,is analyzed,and a mathematical model for the system design is established to compute the motor performance from the input parameters,including the input variables and model *** input parameter uncertainties are quantified,and a sensitivity analysis of the model parameter uncertainties is conducted to identify the most important model parameter uncertainties for *** DDO and probabilistic UDO methods are applied to conceptual designs for an HRM to be used as a substitute for the liquid rocket motor(LRM)of the Ascent Propulsion *** conceptual design results show that HRMs have several advantages as an alternative to the LRM of the Ascent Propulsion System,including nontoxic propellant combination,small motor volume,and comparable functions,such as restarting and *** of the DDO and UDO results indicate that the UDO method achieves more robust and reliable optimal designs than the DDO *** probabilistic UDO method can be used to develop better conceptual designs for HRMs.

关键词： hybrid rocket motor deterministic design optimization uncertainty-based design optimization sensitivity analysis manned lunar landing

hybrid uncertainty-based design optimization and its application to hybrid rocket motors for manned lunar landing

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Chinese Journal of Aeronautics 2017年第2期30卷 719-725页

作者： Zhu Hao Tian Hui Cai Guobiao School of Aeronautics Science and Engineering Beihang University Beijing 100083 China

Design reliability and robustness are getting increasingly important for the general design of aerospace systems with many inherently uncertain design *** paper presents a hybrid uncertainty-based design optimization（UDO） method developed from probability theory and interval *** of the uncertain design parameters which have sufficient information or experimental data are classified as random variables using probability theory,while the others are defined as interval variables with interval *** a hybrid uncertainty analysis method based on Monte Carlo simulation and Taylor series interval analysis is developed to obtain the uncertainty propagation from the design parameters to system *** design optimization strategies,including deterministic design optimization（DDO）,probabilistic UDO and hybrid UDO,are applied to the conceptual design of a hybrid rocket motor（HRM） used as the ascent propulsion system in Apollo lunar *** comparison,the hybrid UDO is a feasible method and can be effectively applied to the general design of aerospace systems.

关键词： hybrid rocket motor hybrid uncertainty-based design optimization Manned lunar landing Uncertainty analysis

Geometric effects of fuel regression rate in hybrid rocket motors

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Science China(Technological Sciences) 2016年第5期59卷 807-813页

作者： CAI GuoBiao ZHANG YuanJun WANG PengFei HUI Tian ZHAO Sheng YU NanJia School of Astronautics Beihang University Beijing 100191 China Beijing Institute of Aerospace Systems Engineering Beijing 100076 China

The geometric configuration of the solid fuel is a key parameter affecting the fuel regression rate in hybrid rocket motors. In this paper, a semi-empirical regression rate model is developed to investigate the geometric effect on the fuel regression rate by incorporating the hydraulic diameter into the classical model. The semi-empirical model indicates that the fuel regression rate decreases with increasing hydraulic diameter and is proportional to dh?0.2 when convective heat transfer is dominant. Then a numerical model considering turbulence, combustion, solid fuel pyrolysis, and a solid–gas coupling model is established to further investigate the geometric effect. Eight motors with different solid fuel grains are simulated, and four methods of scaling the regression rate between different solid fuel grains are compared. The results indicate that the solid fuel regression rates are approximate the same when the hydraulic diameters are equal. The numerical results verify the accuracy of the semi-empirical model.

关键词： geometric effect regression rate hydraulic diameter hybrid rocket motor

Steady-state coupled analysis of flowfields and thermochemical erosion of C/C nozzles in hybrid rocket motors

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Science China(Technological Sciences) 2015年第3期58卷 574-586页

作者： ZHAO Sheng TIAN Hui WANG PengFei YU NanJia CAI GuoBiao School of Astronautics Beihang University

A hybrid rocket can be used in various applications and is an attractive propulsion system. However, serious erosion of nozzles is common in motor firing operations, which could restrict the application of hybrid rocket motors. Usually, the serious erosion is attributed to the high concentration of oxidizing species in hybrid motors, while the details of flowfields in the motors are not paid special attention to. In this paper, first the thermochemical erosion of C/C nozzle is simulated coupled with the flowfields in a 98% H2O2/hydroxyl-terminated polybutadiene（HTPB） hybrid rocket motor. The simulation is made on a typical axisymmetric motor, including a pre-combustion chamber, an aft-combustion chamber and nozzle structures. Thermochemica reactions of H2 O, CO2, OH, O and O2 with C are taken into account. Second, the change of flowfields due to fuel regression during motor firing operations is considered. Nozzle erosion in different flowfields is evaluated. Third, the results of nozzle erosion in the coupled simulation are compared with those under uniform and chemical equilibrium flow and motor firing test results. The results of simulation and firing tests indicate that the thermochemical erosion of nozzles in hybrid motors should be calculated coupled with flowfields in the motor. In uniform and chemical equilibrium flowfields, the erosion rate is overestimated. The diffusion flame in hybrid motors protects the nozzle surface from the injected oxidizer and high temperature products in flowfields, leading to a relatively fuel-rich environment above the nozzle. The influence of OH and the geometry of motor should also be considered in the evaluation of nozzle erosion in hybrid motors.

关键词： hybrid rocket motor C/C nozzle thermochemical erosion