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Numerical investigation of dynamic characteristics of dual throat nozzle and bypass dual throat nozzle in thrust vectoring starting process

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Chinese Journal of Aeronautics 2024年第10期37卷 184-206页

作者： Yuqi ZHANG Jinglei XU Minglei CAO Ruifeng PAN Shuai HUANG key laboratory of inlet and exhaust system technology of ministry of education Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State key laboratory of Mechanics and Control of Aeronautics and Astronautics Structures Nanjing 210016China

The Bypass Dual Throat Nozzle(BDTN)is a novel fluidic Thrust Vectoring(TV)nozzle,it switches to TV state by opening the valve in the *** greatly manipulate the BDTN,the dynamic characteristics in the TV starting process should be *** paper conducts numerical simulations to grasp the variation processes of performances and the flow field evolution of BDTN and Dual Throat Nozzle(DTN).The dynamic responses of TV starting in typical DTN models are investigated at ***,the TV starting processes of BDTN in different Nozzle Pressure Ratio(NPR)conditions are simulated,and the valve opening durations(T)are also *** the expected TV direction is achieved in the DTN,the jet is deflected to the opposite direction at the beginning of the dynamic process,which is called the reverse TV ***,this phenomenon disappears in the *** larger injection width of DTN intensifies unsteady oscillations,and the reverse TV phenomenon is *** the BDTN,T determines the delay degree of performance variations compared to the static results,which is called hysteresis *** NPR=10,the hysteresis affects the final stable performance of *** study analyses the dynamic characteristics in DTN and BDTN,laying a foundation for further design of nozzles and control strategies.

关键词： Dual Throat Nozzle(DTN) Bypass Dual Throat Nozzle(BDTN) Dynamic characteristic Thrust vectoring starting process Cavity vortex Hysteresis effect

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Composite Adaptive Control of Belt Polishing Force for Aero-engine Blade

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Chinese Journal of Mechanical Engineering 2013年第5期26卷 988-996页

作者： ZHsAO Pengbing SHI Yaoyao key laboratory of Contemporary Design and Integrated Manufacturing technology of ministry of education Northwestern Polytechnical University

The existing methods for blade polishing mainly focus on robot polishing and manual *** to the difficulty in high-precision control of the polishing force,the blade surface precision is very low in robot polishing,in particular,quality of the inlet and exhaust edges can not satisfy the processing *** grinding has low efficiency,high labor intensity and unstable processing quality,moreover,the polished surface is vulnerable to burn,and the surface precision and integrity are difficult to *** order to further improve the profile accuracy and surface quality,a pneumatic flexible polishing force-exerting mechanism is designed and a dual-mode switching composite adaptive control(DSCAC) strategy is proposed,which combines Bang-Bang control and model reference adaptive control based on fuzzy neural network(MRACFNN) *** the mode decision-making mechanism,Bang-Bang control is used to track the control command signal quickly when the actual polishing force is far away from the target value,and MRACFNN is utilized in smaller error ranges to improve the system robustness and control *** on the mathematical model of the force-exerting mechanism,simulation analysis is implemented on *** results show that the output polishing force can better track the given ***,the blade polishing experiments are carried out on the designed polishing *** results show that DSCAC can effectively mitigate the influence of gas compressibility,valve dead-time effect,valve nonlinear flow,cylinder friction,measurement noise and other interference on the control precision of polishing force,which has high control precision,strong robustness,strong anti-interference ability and other advantages compared with *** proposed research achieves high-precision control of the polishing force,effectively improves the blade machining precision and surface consistency,and significantly reduces the surface roughness.

关键词： blade polishing force Bang-Bang control fuzzy neural network model reference adaptive control

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system Analysis on Supercritical CO_2 Power Cycle with Circulating Fluidized Bed Oxy-Coal Combustion

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Journal of Thermal Science 2019年第3期28卷 505-518页

作者： SHI Yan ZHONG Wenqi SHAO Yingjuan XIANG Jun key laboratory of Energy Thermal Conversion and Control of ministry of education School of Energy and Environment Southeast University State key laboratory of Coal Combustion School of Energy and Power Engineering Huazhong University of Science and Technology

Supercritical carbon dioxide(S-CO_2) Brayton power cycle is a competitive technology to achieve high efficiency in a variety of applications. However, in coal power applications, the CO_2 generated from coal combustion still discharges into the atmosphere causing a series of environment problems. In this work, an 300 MWe S-CO_2 power cycle with circulating fluidized bed(CFB) oxy-coal combustion was established including air separation unit(ASU), CFB boiler, recuperator system and carbon dioxide compression and purification unit(CPU). Based on the material and energy conservation, the cycle efficiency of S-CO_2(620°C, 25 MPa) Brayton power cycle with CFB oxy-coal combustion is evaluated compared to the oxy-coal combustion steam Rankine cycle and S-CO_2 Brayton power cycle with the 31.65 kg/s coal supply. After that, the influence of several factors, e.g., exhaust flue gas temperature, split ratio in recuperator system and the oxygen supply on the cycle efficiency was investigated and analyzed. The results show that the net efficiency of S-CO_2 power cycle with CFB oxy-coal combustion(32.67%) is much higher than the steam Rankine cycle utilizing CFB with 17.5 Mpa, 540°C steam(27.3%), and 25 Mpa, 620°C steam(30.15%) under the same exhaust flue gas temperature. In addition, lower exhaust flue gas temperature and higher split ratio are preferred to achieve higher cycle efficiency. Lower oxygen supply can reduce the energy consumption of ASU and CPU, further increasing the system net efficiency. However, the energy losses of ASU and CPU are still very large in oxy-coal combustion and need to be improved in further work.

关键词： S-CO2 oxy-coal combustion CO2 capture CFB boiler process simulation

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Numerical simulation and experimental study on the leakage of continuous rotary electro-hydraulic servo motor

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High technology Letters 2021年第3期27卷 272-281页

作者： Wang Xiaojing Peng Yiwen Li Chunhui key laboratory of Advanced Manufacturing and Intelligent technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080P.R.China

In order to study the influence of inlet and outlet pressure difference and triangular buffer groove on the internal leakage of continuous rotary electro-hydraulic servo motor,the flow field model of motor with and without triangular groove is established *** mesh model is *** pressure distribution of the internal flow field under different pressure difference is analyzed by ***,the gap leakage under different pressure difference is calculated,and the leakage curve is ***,continuous rotary electro-hydraulic servo motor experimental system is built to conduct the internal leakage test,and the leakage under different pressure difference is measured and compared with the simulation *** results show that the occurrence of leakage in the motor can be reduced by setting the triangular buffer groove on the flow plate,the simulation and experimental results are *** can be concluded that the larger the pressure difference between the inlet and the outlet of the motor,the larger the gap *** research lays foundation for the application of continuous rotary electro-hydraulic servo motor.

关键词： continuous rotary electro-hydraulic servo motor internal leakage fluent triangular buffer groove

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Experiment Investigation and Control Strategies on Two-Phase Refrigerant Injection Heat Pump system for Electric Vehicle in Start-up Stage

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Journal of Thermal Science 2021年第3期30卷 828-839页

作者： QIN Fei LIU Hanzhou ZOU Huiming CHEN Deqi TIAN Changqing key laboratory of Low-grade Energy Utilization Technologies and systems Ministry of EducationChongqing UniversityChongqing 400044China Beijing key laboratory of Thermal Science and technology and key laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Due to the poor heating performance and operating safety in low ambient temperature,traditional Air Source Heat Pump(ASHP)for Electric Vehicles(EVs)has many limits in cold region,which can be solved by the ASHP with refrigerant *** the start-up stage of EV in winter,the inlet air temperature of the in-car condenser is the same as the ambient *** this situation,the performance and control strategy of the heat pump require special *** the present study,a series of experiments were carried out on the heating performance of the Refrigerant Injection Heat Pump(RIHP)system in start-up stage of EV,at the ambient temperature from–20℃ to–5℃.The effects of compressor speed and injected refrigerant state on the heating performance of the system were discussed in *** to the results,the control strategies during start-up stage have been discussed in the end of the *** study provides a practical control strategy for the RIHP system during the start-up stage of electric vehicles,helping to efficiently operate electric vehicles in cold regions.

关键词： refrigerant injection heat pump system heating performance electric vehicle start-up stage control optimization

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Study on the Performance of Organic Rankine Cycle-Heat Pump(ORC-HP) Combined system Powered by Diesel Engine exhaust

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Journal of Thermal Science 2019年第5期28卷 1065-1077页

作者： ZHAO Tenglong YU Fei ZHANG Hongguang WU Yuting WANG Yan College of Environmental and Energy Engineering Beijing University of Technology Beijing 100124 China MOE(ministry of education)key laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy Conversion Beijing University of Technology Beijing 100124 China

This study presents an ORC-HP combined system driven by diesel engine exhaust. This paper focuses on the feasibility and performance of the combined system under heating mode to heat a coach. The performances of the combined system with different parameters, including condensation temperature and evaporation pressure in ORC system, gas cooler outlet pressure, gas cooler outlet temperature and evaporation temperature in HP system, have been analyzed. The results show that the combined system can fully meet the demand of heat production. The optimal flow division ratio(rp) of 0.32 is selected by analyzing the system performance. Low condensation temperature is beneficial to the combined system performance. There exists a suitable range of evaporation temperature, gas cooler outlet pressure and gas cooler outlet temperature to achieve excellent performance. The heating coefficient of performance(COP_h) shows a first increasing and then decreasing trend with gas cooler outlet pressure, namely there exists an optimal gas cooler outlet pressure that achieves the maximum COP_h. The maximum total efficiency, COP_h and heating capacity can reach up to 48.44%, 4.78 and 176.56 kW, respectively. These results show significant energy savings by applying the ORC-HP combined system.

关键词： organic Rankine cycle heat pump combined system total efficiency COPh

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An improved high-fidelity adaptive model for integrated inlet-engine-nozzle based on mechanismdata fusion

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Chinese Journal of Aeronautics 2024年第8期37卷 190-207页

作者： Chen WANG Ziyang YU Xian DU Ximing SUN School of Control Science and Engineering Dalian University of TechnologyDalian 116024China key laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of EducationDalian University of TechnologyDalian 116024China

Nowadays,there has been an increasing focus on integrated flight propulsion control and the inlet-exhaust design for the aero-propulsion *** component-level models are inadequate due to installed performance deviations and mismatches between the real engine and the model,failing to meet the accuracy requirements of supersonic *** paper establishes a quasi-one-dimensional model for the inlet-exhaust system and conducts experimental ***,a mechanism-data fusion adaptive modeling scheme using an Extreme Learning Machine based on the Salp Swarm Algorithm(SSA-ELM)is *** study reveals the inlet model’s efficacy in reflecting installed performance,flow matching,and mitigating pressure distortion,while the nozzle model accurately predicts flow coefficients and thrust coefficients,and identifies various operational *** model’s output closely aligns with typical experimental *** combining offline optimization and online adaptive correction,the mechanismdata fusion adaptive model substantially reduces output errors during regular flights and varying levels of degradation,and effectively handles gradual degradation within a single flight ***,the mechanism-data fusion adaptive model holistically addresses total pressure errors within the inlet-exhaust system and normal shock location *** approach significantly curbs performance deviations in supersonic *** example,at Ma=2.0,the system error impressively drops from 34.17%to merely 6.54%,while errors for other flight conditions consistently stay below the 2.95%*** findings underscore the clear superiority of the proposed method.

关键词： Aero-propulsion system Integrated inlet-enginenozzle Component-level model On-board adaptive model Mechanism-data fusion Extreme learning machine

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A PMMA Passive Micromixer with Three-Dimensional Tortuous Mixing Chamber

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Journal of Harbin Institute of technology(New Series) 2014年第5期21卷 85-90页

作者： He Zhang Xiao-Wei Liu Jia-Lu Tang Xiao-Wei Han Li Tian key laboratory of Micro-systems and Micro-structures Manufacturing ministry of education Harbin Institute of Technology College of Electrical and Information Engineering Heilongjiang Institute of technology

In this paper,we design and fabricate a novel three-dimensional passive-micro-mixer by using Polymethyl methacrylate( PMMA). The mixer is fabricated by using ultra-precision engraving machine and bonded by an organic solvent fumigation bonding method. The mixer combines two fluid streams into a mixing chamber integrated with T-shaped pre-mixing and six tortuous shaped mixing elements. We have employed three-dimensional numerical simulations to evaluate the mixing efficiency. The simulation results indicate,under inlet fluid pressure p = 10( Pa), compared to the planar serpentine mixer and tortuous mixer,the concentration fluctuation range at the outlet diagonal reduce to 48% and 71. 6% respectively. And the mixing concentration variances also show that the mixing efficiency has a significant increase. We characterize the device by using visualization microscope,and the results are consistent with the simulation data. The device demonstrates the promising capabilities for micro total analysis system integration.

关键词： microfluidic passive mixer 3D tortuous microstructure

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Performance study on three-stage power system of compressed air vehicle based on single-screw expander

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Science China(Technological Sciences) 2010年第8期53卷 2299-2303页

作者： HE Wei,WU YuTing ,MA ChongFang&MA GuoYuan key laboratory of Enhanced Heat Transfer and Energy Conservation,ministry of education,and key laboratory of Heat Transfer and Energy Conversion,Beijing Municipality,College of Environmental and Energy Engineering,Beijing University of technology,Beijing 100124,China key laboratory of Enhanced Heat Transfer and Energy Conservation Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion Beijing Municipality College of Environmental and Energy Engineering Beijing University of Technology Beijing China

A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power *** different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each *** results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,*** also showed that heating up inlet air or increasing the expander efficiency might improve the power *** output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"*** new system showed good structure and power performances.

关键词： compressed-air engine single screw expander three-stage power system

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Control design of 60kW PEMFC generation system for residential applications

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第9期14卷 679-685页

作者： Ying-ying ZHANG Ying ZHANG Xi LI Guang-yi CAO Shandong Provincial key laboratory of Ocean Environment Monitoring technology Institute of Oceanographic Instrumentation Shandong Academy of Sciences Control Science and Engineering Department Key Laboratory of the Ministry of Education for Image Processing and Intelligent Control Huazhong University of Science and Technology Fuel Cell Institute Department of Automation Shanghai Jiao Tong University

This paper presented a control design methodology for a proton exchange membrane fuel cell (PEMFC) generation system for residential applications. The dynamic behavior of the generation system is complex in such applications. A comprehensive control design is very important for achieving a steady system operation and efficiency. The control strategy for a 60 kW generation system was proposed and tested based on the system dynamic model. A two-variable single neuron proportional-integral (PI) decoupling controller was developed for anode pressure and humidity by adjusting the hydrogen flow and water injection. A similar controller was developed for cathode pressure and humidity by adjusting the exhaust flow and water injection. The desired oxygen excess ratio was kept by a feedback controller based on the load current. An optimal seeking controller was used to trace the unique optimal power point. Two negative feedback controllers were used to provide AC power and a suitable voltage for residential loads by a power conditioning unit. Control simulation tests showed that 60 kW PEMFC generation system responded well for computer-simulated step changes in the load power demand. This control methodology for a 60 kW PEMFC generation system would be a competitive solution for system level designs such as parameter design, performance analysis, and online optimization.

关键词： Proton exchange membrane fuel cell (PEMFC) Generation system Control strategy decoupling control Optimalseeking control

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