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Shock Wave Induced separation control By Streamwise Vortices

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Journal of Thermal Science 2005年第3期14卷 249-253页

作者： Ryszard SZWABA Technical University of Liberec Faculty of Mechanical Engineering Division of Power Engineering. Halkova 6 461 17 Liberec Czech Republic

control of shock wave and boundary layer interaction finds still a lot of attention. Methods of this interaction control have been especially investigated in recent decade. This research was mostly concerned with flows without separation. However, in many applications shock waves induce separation often leads to strong unsteady effects. In this context it is proposed to use streamwise vortices for the interaction control. The results of experimental investigations are presented here. The very promising results were obtained, meaning that the incipient separation was postponed and the separation size was reduced for the higher Mach numbers. The decrease of the RMS of average shock wave oscillation was also achieved.

关键词： streamwise vortices separation control boundary layer shock wave

A Karman-Vortex Generator for passive separation control in a conical diffuser

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Science China(Physics,Mechanics & Astronomy) 2012年第5期55卷 828-836页

作者： ZHANG YuFei CHEN HaiXin FU Song School of Aerospace Engineering Tsinghua UniversityBeijing 100084China

Flow separation in a conical diffuser with large divergence angle （29.14°） and large area ratio （3.533） is eliminated by a novel passive flow control device called Karman-Vortex Generator （KVG）. The effect of the KVG is verified and investigated by the URANS, DES and DDES methods based on the SST model. CFD results show that the performance coefficient of the diffuser can be doubled by the KVG, and the total pressure recovery coefficient can be improved by about 1.2%. DES and DDES re- suits show that the KVG can introduce a Karman-vortex street frequency in the diffuser. This frequency decays rapidly, and could not be detected in the ending plane of the expansion section, Different KVG configurations with different locations and dimensions are numerically simulated and compared. Some suggestions are provided.

关键词： conical diffuser Karman-Vortex Generator separation control DES

Novel lift enhancement method based on zero-mass-flux jets and its adaptive controlling laws design

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Acta Mechanica Sinica 2021年第10期37卷 1567-1579,I0003页

作者： Zhijie Zhao Zhenbing Luo Bin Xu Xiong Deng Yuyan Guo Wenqiang Peng Shiqing Li College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China School of Automation Northwestern Polytechnical UniversityXi’an710072China

For lessening the weight and volume of flow control system,enlarging the circulation control applying area of angle of attack(AOA),and achieving nice controlling characteristics,a novel lift enhancement method based on dual synthetic jet actuators(DSJAs)and synthetic jet actuator(SJA),and an adaptive proportional integral and differential(PID)algorithm based on radial basis function neural network are *** are uniformly located along the chord to suppress the separation and trailing-edge SJA is applied to achieve the high *** of actuators are modulated to realize the real speed profile and on–off controlling laws of DSJAs are *** simulations show that DSJAs and SJA could suppress the separation completely and move leading-edge stagnation point and trailing-edge separation point downstream even at AOA of 19°,hence achieve the highest lift and nose-down moment augmentation(ΔCl_(max)=0.92,ΔCm_(max)=0.02534),andΔL/D can reach 11.39 at AOA of 18°.Stalling is delayed to more than 19°.Linear lift area and pitch-break angle are both increased to 16°.ΔCl/C_(μ) can reach 76.7,indicating the greatest control *** results of adaptive PID control,whose controlling effects are proved better than PID,indicate that lift could track the objective with the rise time of 0.0325 s and finally keep steady,suggesting the nice stability and rapidness.

关键词： Lift enhancement Circulation control separation control Synthetic jet Adaptive control

A survey of safety separation management and collision avoidance approaches of civil UAS operating in integration national airspace system

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维普期刊数据库

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Chinese Journal of Aeronautics 2020年第11期33卷 2851-2863页

作者： Xiangmin GUAN Renli LYU Hongxia SHI Jun CHEN Department of General Aviation Civil Aviation Management Institute of ChinaBeijing 100102China General Aviation Institute of Zhejiang JianDe Hangzhou 311600China School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUnited Kingdom

Recent years have witnessed a booming of the industry of civil Unmanned Aircraft System(UAS).As an emerging industry,the UAS industry has been attracting great attention from governments of all countries and the aviation *** are highly digitalized,informationized,and intelligent;therefore,their integration into the national airspace system has become an important trend in the development of civil ***,the complexity of UAS operation poses great challenges to the traditional aviation regulatory system and technical *** to prevent collisions between UASs and between UAS and manned aircraft to achieve safe and efficient operation in the integrated operating airspace has become a common challenge for industry and academia around the *** recent years,the international community has carried out a great amount of work and experiments in the air traffic management of UAS and some of the key *** paper attempts to make a review of the UAS separation management and key technologies in collision avoidance in the integrated airspace,mainly focusing on the current situation of UAS Traffic Management(UTM),safety separation standards,detection system,collision risk prediction,collision avoidance,safety risk assessment,etc.,as well as an analysis of the bottlenecks that the current researches encountered and their development trends,so as to provide some insights and references for further research in this ***,this paper makes a further summary of some of the research highlights and challenges.

关键词： Air transportation Collision avoidance Safety separation control Unmanned aircraft system

Influence of Air-Jet Vortex Generator Diameter on separation Region

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Journal of Thermal Science 2013年第4期22卷 294-303页

作者： Ryszard Szwaba Institute of Fluid-Flow Machinery Polish Academy of Sciences (IMP PAN)

control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control.

关键词： shock wave boundary layer separation control streamwise vortices air-jet vortex generator