背风面合成射流作用下方柱绕流统计特性  

Statistical characteristics of flow around square cylinder with synthetic jet issued from rear surface

作　　者：曲嫄 王晋军[1] QU Yuan;WANG Jinjun(Key laboratory of Fluid Mechanics of Ministry of Education,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学流体力学教育部重点实验室,北京100191

出　　处：《空气动力学学报》2020年第5期957-963,I0003,共8页Acta Aerodynamica Sinica

基　　金：国家自然科学基金创新研究群体项目(11721202)。

摘　　要：为了研究方柱背风面施加狭缝合成射流对流场统计特性的影响规律,采用时间解析的粒子图像测速技术测量了合成射流雷诺数■时,无量纲激励频率fe/f0和无量纲冲程L_0/w组合作用下的方柱绕流流场。研究结果表明:合成射流会在方柱背风面诱导产生新的回流区,改变了尾迹流场的拓扑结构、雷诺应力分布、速度分布和阻力特性等;发现存在一个无量纲激励频率和无量纲冲程的优化组合,使合成射流减阻效果最佳。在本实验条件下得到(f_e/f_0,L_0/w)=(4.0,36.3)时,最大减阻率可达53.7%,此时,对应的尾迹区速度亏损恢复更快、速度脉动水平更低、回流区更长。This study aims to investigate the effect of the slot synthetic jet issued from the rear surface of a square cylinder on the statistical characteristics of the flow field.The synthetic jet Reynolds number was kept constant at■.The flow field around the square cylinder was measured using the time-resolved particle image velocimetry(PIV)under different parameter combinations of the dimensionless excitation frequency fe/f0and the dimensionless stroke length L0/w.Results show that the synthetic jet can induce a new recirculation region near the rear surface of the square cylinder and change the wake topology,the distributions of Reynolds stresses,the velocity profiles as well as the drag coefficient.It is found that there is an optimized combination of the dimensionless excitation frequency and the dimensionless stroke length,with which the synthetic jet has the best drag reduction effect.Under the current experimental condition,a maximum drag reduction rate of 53.7%is obtained at(fe/f0,L0/w)=(4.0,36.3),and this case has a faster recovery of mean streamwise velocity deficit in the wake,a lower level of velocity fluctuation and a longer streamwise length of recirculation region.

关 键 词：钝体绕流 流动控制 减阻 合成射流 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]