This paper describes a new actively controlled multi-fan wind tunnel that generates natural wind as a type of turbulence wind tunnel at a reduced cost. The driving section of the wind tunnel has 100 PC cooling fans th...This paper describes a new actively controlled multi-fan wind tunnel that generates natural wind as a type of turbulence wind tunnel at a reduced cost. The driving section of the wind tunnel has 100 PC cooling fans that are controlled by an original embedded system. The fluctuating velocity wind is successfully generated with a mean velocity of 7 m/s and two turbulent intensities of 2% and 3% based on Karman’s power spectrum density function. The case of 2% has the integral scales of 5 m, 10m and 20 m, and the case of 3% has the integral scales of 3 m, 6 m and 15 m with a turbulence grid. In particular, the wind with the turbulent intensity of 2% satisfies the Kolmogorov’s -5/3 multiplication rule of inertial subrange with the frequency range from 0.01 Hz to 2.0 Hz. Consequently, the new wind tunnel can be used for studying engineering technology and research regarding conditions with natural wind.展开更多
Motion control can be considered as the synergistic collaboration of mechanical and electrical engineering, computer science and information technology to apply a controlled force to achieve useful motion in fluid or ...Motion control can be considered as the synergistic collaboration of mechanical and electrical engineering, computer science and information technology to apply a controlled force to achieve useful motion in fluid or soiled electromechanical systems. With the development of computer, electronics, and automatic control theory, motion control comes to a new stage. Great applications are based on the characteristics, stemming from advantages of electronics and modern control technology achievements, having a very good load matching property. Currently, microprocessor-based controllers are invariably used in most applications of drive electronics. The object of this work is to design a position control mechanism system, which can be used in test section of low speed wind tunnel. System load specifications and performance requirements are given. A comprehensive study of mathematical modeling of the mechanism components is given. Procedure for selection of various components with optimum parameters is discussed. After selection and calculation of system parameters to meet the performance requirements, a PID control method is adopted.展开更多
双供水供气系统是保证结冰风洞实现过冷大水滴(Super-cooled Large Droplet,SLD)云雾模拟能力的关键,针对现有喷雾系统存在SLD云雾模拟能力不足、运行包线有待扩展等问题,研制了一套大型结冰风洞双供水供气喷雾控制系统。针对喷雾系统...双供水供气系统是保证结冰风洞实现过冷大水滴(Super-cooled Large Droplet,SLD)云雾模拟能力的关键,针对现有喷雾系统存在SLD云雾模拟能力不足、运行包线有待扩展等问题,研制了一套大型结冰风洞双供水供气喷雾控制系统。针对喷雾系统控制变量多、测量点数大等特点,基于工业以太网络建立分布式控制系统,制定了试验流程、方法与策略,建立了完善的双供水供气喷雾试验技术,并开展了系统调试与验证。试验结果表明,双路水压、气压控制精度均稳定在1%以内,达到了系统设计指标,该系统可为后续我国飞行器适航审定提供有力支撑。展开更多
A novel variable camber wing driven by ultrasonic motors is proposed.Key techniques of distributed layout of drive mechanisms,coordination control of distributed ultrasonic motors as well as novel flexible skin underg...A novel variable camber wing driven by ultrasonic motors is proposed.Key techniques of distributed layout of drive mechanisms,coordination control of distributed ultrasonic motors as well as novel flexible skin undergoing one-dimensional morphing are studied.The system integration of small variable camber wing is achieved.Distributed layout of parallelogram linkages driven by geared ultrasonic motors is adopted for morphing,aimed at reducing the load for each motor and producing various aerodynamic configurations suitable for different flying states.Programmable system-on-chip(PSoC)is used to realize the coordination control of the distributed ultrasonic motors.All the morphing driving systems are assembled in the interior of the wing.The wing surface is covered with a novel smooth flexible skin in order to maintain wing shape and decrease the aerodynamic drag during morphing.Wind tunnel test shows that the variable camber wing can realize morphing under low speed flight condition.Lift and drag characteristics and aerodynamic efficiency of the wing are improved.Appropriate configurations can be selected to satisfy aerodynamic requirements of different flight conditions.The study provides a practical application of piezoelectric precision driving technology in flow control.展开更多
文摘This paper describes a new actively controlled multi-fan wind tunnel that generates natural wind as a type of turbulence wind tunnel at a reduced cost. The driving section of the wind tunnel has 100 PC cooling fans that are controlled by an original embedded system. The fluctuating velocity wind is successfully generated with a mean velocity of 7 m/s and two turbulent intensities of 2% and 3% based on Karman’s power spectrum density function. The case of 2% has the integral scales of 5 m, 10m and 20 m, and the case of 3% has the integral scales of 3 m, 6 m and 15 m with a turbulence grid. In particular, the wind with the turbulent intensity of 2% satisfies the Kolmogorov’s -5/3 multiplication rule of inertial subrange with the frequency range from 0.01 Hz to 2.0 Hz. Consequently, the new wind tunnel can be used for studying engineering technology and research regarding conditions with natural wind.
文摘Motion control can be considered as the synergistic collaboration of mechanical and electrical engineering, computer science and information technology to apply a controlled force to achieve useful motion in fluid or soiled electromechanical systems. With the development of computer, electronics, and automatic control theory, motion control comes to a new stage. Great applications are based on the characteristics, stemming from advantages of electronics and modern control technology achievements, having a very good load matching property. Currently, microprocessor-based controllers are invariably used in most applications of drive electronics. The object of this work is to design a position control mechanism system, which can be used in test section of low speed wind tunnel. System load specifications and performance requirements are given. A comprehensive study of mathematical modeling of the mechanism components is given. Procedure for selection of various components with optimum parameters is discussed. After selection and calculation of system parameters to meet the performance requirements, a PID control method is adopted.
文摘双供水供气系统是保证结冰风洞实现过冷大水滴(Super-cooled Large Droplet,SLD)云雾模拟能力的关键,针对现有喷雾系统存在SLD云雾模拟能力不足、运行包线有待扩展等问题,研制了一套大型结冰风洞双供水供气喷雾控制系统。针对喷雾系统控制变量多、测量点数大等特点,基于工业以太网络建立分布式控制系统,制定了试验流程、方法与策略,建立了完善的双供水供气喷雾试验技术,并开展了系统调试与验证。试验结果表明,双路水压、气压控制精度均稳定在1%以内,达到了系统设计指标,该系统可为后续我国飞行器适航审定提供有力支撑。
基金supported by the National Natural Science Foundation of China(Nos.50905085,91116020)the Aviation Science Foundation of China(No.20100112005)
文摘A novel variable camber wing driven by ultrasonic motors is proposed.Key techniques of distributed layout of drive mechanisms,coordination control of distributed ultrasonic motors as well as novel flexible skin undergoing one-dimensional morphing are studied.The system integration of small variable camber wing is achieved.Distributed layout of parallelogram linkages driven by geared ultrasonic motors is adopted for morphing,aimed at reducing the load for each motor and producing various aerodynamic configurations suitable for different flying states.Programmable system-on-chip(PSoC)is used to realize the coordination control of the distributed ultrasonic motors.All the morphing driving systems are assembled in the interior of the wing.The wing surface is covered with a novel smooth flexible skin in order to maintain wing shape and decrease the aerodynamic drag during morphing.Wind tunnel test shows that the variable camber wing can realize morphing under low speed flight condition.Lift and drag characteristics and aerodynamic efficiency of the wing are improved.Appropriate configurations can be selected to satisfy aerodynamic requirements of different flight conditions.The study provides a practical application of piezoelectric precision driving technology in flow control.
基金Projects(51978589,52322811)supported by the National Natural Science Foundation of ChinaProject(2682021CG014)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2021TPL_T03)supported by the Scientific Research Foundation of State Key Laboratory of Traction Power,China。
