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

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

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A comprehensive fluid-solid coupling dynamic simulation for spatiotemporal distribution of regression rate in hybrid rocket motors

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Chinese Journal of Aeronautics 2024年第9期37卷 100-112页

作者： Tianfang WEI Guobiao CAI Hui TIAN Xiangyu MENG Xianzhu JIANG Xiaoming GU School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of Education Beijing 100191China

The spatiotemporal distribution characteristics of the regression rate are crucial aspects of the research on Hybrid Rocket Motor(HRM). This study presents a pioneering effort in achieving a comprehensive numerical simulation of fluid dynamics and heat transfer in both the fluid and solid regions throughout the entire operation of an HRM. To accomplish this, a dynamic grid technique that incorporates fluid–solid coupling is utilized. To validate the precision of the numerical simulations, a firing test is conducted, with embedded thermocouple probes being used to measure the inner temperature of the fuel grain. The temperature variations in the solid fuel obtained from both experiment and simulations show good agreement. The maximum combustion temperature and average thrust obtained from the simulations are found to deviate from the experimental results by only 3.3% and 2.4%, respectively. Thus, it can be demonstrated that transient numerical simulations accurately capture the fluid–solid coupling characteristics and transient regression rate. The dynamic simulation results of inner flow field and solid region throughout the entire working stage reveal that the presence of vortices enhances the blending of combustion gases and improves the regression rate at both the front and rear ends of the fuel grain. In addition, oscillations of the regression rate obtained in the simulation can also be well corresponded with the corrugated surface observed in the experiment. Furthermore, the zero-dimension regression rate formula and the formula describing the axial location dependence of the regression rate are fitted from the simulation results, with the corresponding coefficients of determination(R^(2)) of 0.9765 and 0.9298, *** research serves as a reference for predicting the performance of HRM with gas oxygen and polyethylene, and presents a credible way for investigating the spatiotemporal distribution of the regression rate.

关键词： Hybrid Rocket Motor(HRM) Transient numerical simulation Fluid-solid couplingheat transfer Spatiotemporal distribution of regression rate dynamic grid

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Experiment research on regression rate of aluminized solid propellant with HMX using reconstruction techniques

Experiment research on regression rate of aluminized solid p...

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2023 International Conference on Mechanical, Aerospace and Electronic Systems, MAES 2023

作者： Wei, T.F. Cai, G.B. Tian, H. Lu, Y.D. Niu, X.T. School of Astronautics Beihang University 100191 China Key Laboratory of Spacecraft Design Optimization & Dynamic Simulation Technologies Ministry of Education China

In this research, a firing test was conducted on a Hybrid Rocket Motor (HRM) that operates using an aluminized solid propellant containing HMX and Hydrogen Peroxide (HP). The instantaneous regression rate of HRM is determined using reconstruction techniques, and the formula of regression rate is fitted by reconstruction techniques and traditional weight-loss method. The utilization of the reconstruction method presents a notable advantage, as it allows for the determination of the regression rate's sensitivity to variations in oxidizer mass flux. Additionally, this method enables the fitting of the regression rate formula based on data obtained from a single firing test. The average value of regression rate of four times firing test are 0.944, 0.529, 0.595 and 0.486 mm/s. According to the weight-loss method and reconstruction techniques, the coefficients of determination (R2) of regression rate formula fitting are 0.8867 and 0.93 respectively, indicating that the accuracy of the fitting is better than that of traditional method. Overall, this paper presents a comparison of traditional weight-loss method and reconstruction techniques for providing a critical preference for the research of regression rate of HRM. © Published under licence by IOP Publishing Ltd.

关键词： Sensitivity analysis

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Numerical analysis of hydrogen peroxide injection effect on the combustion characteristics of a staged combustion aft-injected hybrid rocket motor

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Acta Astronautica 2025年 234卷 429-444页

作者： Deng, Luojun Ping, Li Chen, Changrui Wang, Weizong Zhang, Guangchuan Yang, Yuxin School of Astronautics Beihang University Beijing100191 China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies Beijing100191 China The Institute of Xi'an Aerospace Solid Propulsion Technology Xi'an710025 China National Key Laboratory of Solid Rocket Propulsion Xi'an710025 China

The staged combustion aft-injected hybrid rocket motor is a novel propulsion system that utilizes an independent fuel-rich solid propellant gas generator, with high performance and promising application prospects. However, its performance is significantly influenced by the hydrogen peroxide injection scheme. Therefore, a three-dimensional numerical model based on the Euler-Lagrange framework for multiphase turbulent flow and combustion is established. Based on the validated model, the detailed flow and combustion characteristics are carefully discussed. It is found that the combustion flow field exhibits distinct partition characteristics. And the recirculation zones appearing in the motor head enhance mixing combustion. Then, the effects of axial injection angles and axial/swirl injection ratios on the combustion flow field and motor performance are investigated. The results indicate that the larger the axial injection angle, the deeper and earlier the mixing of hydrogen peroxide and primary combustion gas occurs, thereby enhancing the combustion efficiency and specific impulse. To achieve better motor performance, the axial injection angle should not be less than 30°. Additionally, a smaller axial/swirl injection ratio leads to more droplets accumulating near the wall, resulting in incomplete mixing evaporation and hence motor performance loss. However, this also significantly decreases the temperature near the motor head and wall, which positively impacts the motor's thermal protection. This study suggests that the axial/swirl injection ratio should be controlled around 4:1, as the specific impulse decreases by only 2.3 %. This paper provides valuable guidance for the design of injection schemes for the staged combustion aft-injected hybrid rocket motor. © 2025

关键词： Boosters (rocket)

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design and experimental research of a sub-Newton N_(2)O monopropellant thruster with inner-heater

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Chinese Journal of Aeronautics 2022年第5期35卷 309-318页

作者： Kaiyang LI Jie FANG Wei SUN Bing SUN Guobiao CAI School of Astronautics Beihang UniversityBeijing 100083China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies of Ministry of Education Beihang UniversityBeijing 100083China China Academy of Space Technology Beijing 100094China

Nitrous oxide(N_(2)O)is a green propellant with excellent application prospects.A subNewton N_(2)O monopropellant thruster with inner-heater and a N_(2)O self-pressurization stable supply system with regenerative heat compensation are designed in this *** experimental research of the thruster is described,including measurements of preheating power,activation temperature,vacuum thrust,specific impulse,life-span and pulsed operation *** inserting the heater into the catalyst-bed,preheating efficiency of the heater is significantly improved compared to the thruster with ***,the preheating power demand of the thruster is successfully reduced to around 10 *** mean vacuum thrust of 322 mN is attained and the corresponding specific impulse reaches 162s at the mass flow rate of 0.2 g/*** activation temperature of 523 K is achieved,and the activation performance of the thruster is affected by the loading factor.A long term hot-firing test longer than 12000 s is *** pulsed operation performance of the inner-preheating thruster is also studied by measuring chamber *** with different magnitudes are produced by adjusting the opening duration of the control valve.A minimum impulse of 81 mN·s is ***,the performance of the thruster is evaluated by comparison with other thrusters of the same *** results indicate that the proposed thruster with inner-heater is superior in terms of preheating power,activation temperature and specific impulse performance.

关键词： Green propellant Monopropellant thruster Nitrous oxide Regenerative heat compensation Self-pressurization

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Numerical Study of Pipeline Distribution Effect on the Performance of Pasty Propellant Rocket Motor

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Space(Science & Technology) 2023年第1期3卷 572-584页

作者： Renjie Hu Weizong Wang Advanced Space Propulsion and Energy Laboratory(ASPEL) School of AstronauticsBeihang UniversityBeijingChina Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies Ministry of EducationBeijingChina Aircraft and Propulsion Laboratory Ningbo Institute of TechnologyBeihang UniversityNingboChina

This paper reports the numerical research on PPRM(pasty propellant rocket motor)through computational fluid dynamics simulation along with pipeline design comparison based on simulation *** structure of PPRM includes feed pipelines,and the propellant is distributed in a cone shape when burnt steadily in the combustion *** a result,the internal flow field presents strong 3-dimensional characteristics,which may lead to the flow *** accurately understand the combustion flow field and flow instability in the PPRM,a numerical simulation of the combustion chamber considering propellant pyrolysis and chemical reaction,coupled with the feed system module,is employed in the *** effect of pipeline distribution,including the pipeline location and the nonuniformity of pipeline diameter on the internal combustion flow characteristics as well as the motor thrust,was *** results show that the vortex caused by the special conical shape of the burning surface leads to pressure *** adjusting the pipeline location and the nonuniformity of pipeline diameter,the distribution of vortex varies dramatically,which leads to different oscillation frequencies and *** some pipeline distribution schemes,there is almost no large vortex in the rocket motor,which greatly eliminates the flow acoustic coupling oscillation of the *** oscillation amplitude decreases from about 5.7%to less than 0.1%.The results will help guide the design of the high-performance feed system and combustion chamber of PPRM.

关键词： vortex oscillation eliminate

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Infrared Small Target Detection Based on Prior Weighed Sparse Decomposition 18th

Infrared Small Target Detection Based on Prior Weighed Spar...

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18th Chinese Conference on Image and Graphics Technology and Application Conference, IGTA 2023

作者： Yang, Dongning Zhang, Haopeng Xie, Fengying Jiang, Zhiguo School of Astronautics Beihang University Beijing102206 China Beijing Key Laboratory of Digital Media Beijing102206 China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies Ministry of Education Beijing102206 China

ISBN: (纸本)9789819975488

Infrared small target detection is a critical topic and research focus in target detection. Compared to visible light and radar detection, infrared imaging-based detection can effectively avoid illumination limitations and potential exposure risks. However, detecting small infrared targets with complex backgrounds and significant noise is challenging, and existing algorithms often have low detection rates, high false alarm rates, long calculation times, and unsatisfactory performance. To address these issues, we proposes an infrared small target detection algorithm based on sparse representation. The algorithm enhances target sparsity through multi-scale contrast saliency mapping and global gray value fusion, leveraging the low rank of the background. We evaluate the proposed method on SIRST dataset and compare its performance with traditional and recent algorithms. The results demonstrate the superiority of our algorithm in terms of detection rate, false alarm rate, and calculation time. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Image resolution

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design optimization of a low-cost three-stage launch vehicle with modular hybrid rocket motors 2

Design optimization of a low-cost three-stage launch vehicle...

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2023 2nd International Conference on Aerospace and Control Engineering, ICoACE 2023

作者： Wenzhi, Hao Hao, Zhu Wei, He Zhiguo, Zhang School of Astronautics Beihang University Beijing100191 China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies Ministry of Education Beijing100091 China Yu Menglun Intelligent Rocket Laboratory Institute of Astronautical Systems Engineering Beijing100076 China

This article investigates the impact of modular propulsion system design on the performance and cost of a three-stage hybrid rocket. Furthermore, it conducts a multi-objective optimization of unit payload cost, take-off mass, and payload mass ratio, considering factors such as the number of motors and layout considerations. The optimization design scheme for the three-stage hybrid rocket is divided into four cases. In the first case, each stage is equipped with a fixed single motor, and each stage is independently optimized without modular design. The second case considers the use of multiple motors in the first and second stages, still without modular design. The third case also involves multiple motors in the first and second stages, but all motors in each stage have identical parameters except for the nozzle expansion ratio, implementing a modular design. In the fourth case, the number and layout of the motor design method are the same as those in the third case, with independent optimization in the third stage using partial modular design. The results indicate that the unit payload cost of the multi-motor non-modular design case can be reduced by 13.12% compared to the single-motor non-modular design case. Within the modular case, the full modular design case is slightly inferior to the partial modular design case. Based on the above data, it can be concluded that the first and second stages of modular rockets offer the best performance and the lowest cost. © Published under licence by IOP Publishing Ltd.

关键词： Multiobjective optimization

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Index allocation for a reusable LOX/CH4 rocket engine

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Chinese Journal of Aeronautics 2021年第2期34卷 432-440页

作者： Yi LI Jie FANG Bing SUN Kaiyang LI Guobiao CAI School of Astronautics Beihang UniversityBeijing 100083China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies(Beihang University) Ministry of EducationBeijing 100083China

Reusable rocket engines are the core components of reusable launch vehicles, and have thus become a major focus of aerospace engineering research in recent years. In practice, subsystem design is based on the overall index allocation of an engine;therefore, a multidisciplinary optimization approach is necessary. In this study, design of a reusable methane/liquid oxygen(LOX/CH4)rocket engine with a gas generator cycle was investigated using multidisciplinary optimization. Two parameters were chosen as design variables: pressure and fuel mix ratio of the main combustion chamber. optimization objectives were specific impulse, structural mass, and life cycle cost of the reusable rocket engine, and constraints were assigned to each discipline according to rocket design requirements. Then, an optimization model was developed, and optimal design parameters were acquired for the LOX/CH4 rocket engine. The proposed method is effective for designing the index allocation of reusable rocket engines and takes into account the multidisciplinary nature of complex systems.

关键词： Index allocation Mass model Multidisciplinary optimization Reliability Rocket engines

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Modelling the effect of deposited grid material on the power coupling of radio frequency ion thrusters

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Journal of Electric Propulsion 2025年第1期4卷 1-27页

作者： Cui, Yunwei Ren, Junxue Wu, Kunlong Chen, Nanyi Pan, Ruojian Mao, Renfan Tang, Haibin School of Space and Environment Beihang University Shahe Higher Education Park Beijing102206 China School of Astronautics Beihang University Shahe Higher Education Park Beijing 102206 People’s Republic of China Beijing102206 China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies of the Ministry of Education Beijing102206 China Laboratory of Space Environment Monitoring and Information Processing Ministry of Industry and Information Technology Beijing102206 China

For radio-frequency(RF) ion thrusters, under nominal operating conditions, sputtering of the screen grid can lead to the formation of a conductive film of the grid material on the inner walls of the discharge chamber which leads to a decrease in RF coupling to the plasma. When the ion beam becomes unfocused, either due to off nominal operating conditions or as a result of lifetime degradation, this process can be accelerated. An RF ion thruster performance model is developed, which can quantitatively simulate the performance degradation caused by sputter deposition on the thruster. This model couples an RF power transmission model, a zero-dimensional thruster discharge chamber model, and a sputter deposition model. An experiment that intentionally enhances the erosion of the accelerator grid to accelerate the formation of the conductive film confirms the power transmission process described by the model. As a result, the deposition on the discharge chamber walls primarily originates from the sputtering of the accelerator grid by the ion beam. At a xenon flow rate of 0.63 sccm and RF power of 42 W, a 2.015 μm copper film deposited on the walls resulting in a decrease in thruster screen grid current. The simulated results indicate that the power absorbed by the plasma decreases after deposition, which is the primary cause of the screen grid current reduction. Using materials with low conductivity for the deposition layer in the construction of the accelerator grids can reduce the impact of the deposition layer on the thruster screen grid current. © The Author(s) 2025.

关键词： Conductive films

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