Characteristics of array of distributed synthetic jets and effect on turbulent boundary layer  

作　　者：Lianshan Lu Dong Li Zhenghong Gao Zhen Cao Yu Bai Jie Zheng 

机构地区：[1]School of Aeronautics,Northwestern Polytechnical University,Xi’an,710072,China

出　　处：《Acta Mechanica Sinica》2020年第6期1171-1190,I0001,共21页力学学报（英文版）

基　　金：The authors would like to acknowledge the financial support received from the project“Drag Reduction via Turbulent Boundary Layer Flow Control(DRAGY)”.The DRAGY project(April 2016-March 2019)is a China-EU Aeronautical Cooperation project,which is co-funded by Ministry of Industry and Information Technology(MIIT),China,and Directorate-General for Research and Innovation(DG RTD),European Commission.

摘　　要：An array of distributed round synthetic jets was used to control a fully developed turbulent boundary layer.The study focused on the related skin friction drag reduction and mechanisms involved.The control effects were analyzed by measuring the streamwise velocities using a hot-wire anemometer downstream of the array.A reduction in the skin friction was observed both in the regions downstream of the orifices and in the regions between two adjacent orifices.A statistical analysis with the variable-interval time-averaging(VITA)technique demonstrated a weakened bursting intensity with synthetic jet in the near-wall region.The streamwise vortices were lifted by the upwash effect caused by synthetic jet and induced less low-speed streaks.The control mechanism acted in a way to suppress the dynamic interaction between the streamwise vortices and low-speed streaks and to attenuate the turbulence production in the near-wall region.The forcing frequency was found to be a more relevant parameter when synthetic jet was applied in turbulent boundary layer flow control.A higher forcing frequency induced a higher reduction in the skin friction.The power spectral density and autocorrelation of the fluctuating velocities showed that the synthetic jets gradually decayed in the streamwise direction,having an effect as far as 34.5 times the displacement thickness that was on the trailing edge of the distributed synthetic jets array.

关 键 词：Distributed synthetic jets Flow control Turbulent boundary layer Skin friction drag reduction HOT-WIRE 

分 类 号：O35[理学—流体力学]