1Department of Energy & Resources Engineering, College of Engineering, Peking University, Beijing 100871 2Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong 3 Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Chongqing University of Technology, Chongqing 400054
Mini-Jet Controlled Turbulent Round Air Jet
DU Cheng1,2, MI Jian-Chun1**, ZHOU Yu2, ZHAN Jie3
1Department of Energy & Resources Engineering, College of Engineering, Peking University, Beijing 100871 2Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong 3 Key Laboratory of Manufacture and Test Techniques for Automobile Parts, Chongqing University of Technology, Chongqing 400054
摘要We report an investigation of the active control of a round air jet by multiple radial blowing mini-jets. The Reynolds number based on the jet exit velocity and diameter is 8000. It is found that once the continuous mini-jets are replaced with pulsed ones, the centerline velocity decay rate K can be greatly increased as the pulsing frequency of mini−jets approaches the natural vortex frequency of the main jet. For example, the K value is amplified by more than 50% with two (or four) pulsed mini-jets blowing, compared with the continuous mini-jets at the same ratio of the mass flow rate of the mini-jets to that of the main jet.
Abstract：We report an investigation of the active control of a round air jet by multiple radial blowing mini-jets. The Reynolds number based on the jet exit velocity and diameter is 8000. It is found that once the continuous mini-jets are replaced with pulsed ones, the centerline velocity decay rate K can be greatly increased as the pulsing frequency of mini−jets approaches the natural vortex frequency of the main jet. For example, the K value is amplified by more than 50% with two (or four) pulsed mini-jets blowing, compared with the continuous mini-jets at the same ratio of the mass flow rate of the mini-jets to that of the main jet.
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2011, Vol. 28 
