摘要
为了探索零质量射流孔间距λ对控制边界层分离的效果,以凸包边界层分离流动为例,在凸包最高点下游布置零质量射流孔,选取了4种射流孔间距,λ/D (D为孔直径)分别为2, 3, 4, 5。采用大涡模拟方法对凸包边界层分离流动及零质量射流流动进行了数值模拟,并对有、无零质量射流控制时的凸包流场进行分析。结果表明,零质量射流产生与传统射流相似的时均速度场,激励时产生的射流使分离区内速度更加饱满;吹气时旋涡在孔后产生气动堵塞,同时将分离区外的高能流体卷入分离区内,使分离减小。吸气时孔上游边界层内低速流体被吸入孔内,孔附近边界层变薄,使分离推迟;当零质量射流孔间距λ/D=2时,间距太小,抑制了旋涡的展向发展。当λ/D=4, 5时,间距过大,旋涡不受抑制更容易扩散。当λ/D=3时,分离区最小。
In order to study the effect of jet spacing λ of zero-net-mass-flux (ZNMF)jets on controlling the separation of boundary layers,separated flow over a wall-mounted hump is used as an example.ZNMF jets are arranged along downstream of the top point of the wall-mounted hump, and four kinds of jet spacing are selected,λ/D (D is the diameter of ZNMF jets)respectively are 2,3,4,5.The boundary layer separation flow of the wall-mounted hump and ZNMF jets control flow separation is investigated by using large eddy simulation (LES)and topological analysis.Results show that the mean velocity field of ZNMF jets is similar to that of continuous jets,and the jet produced during excitation makes the velocity within separation zone more fullness;when blowing, vortexs produce aerodynamic blockage after the holes,and high-energy fluid outside separation zone is indrawn,reducing the separation.During ingesting,low velocity fluid upper boundary layers of holes is indrawn into holes,boundary layers becomes thinner,delaying the separation;when λ/D =2, the spacing is too small and restrains the development of vortex.When λ/D =4 or 5,the spacing is too large and the vortexs are easier to diffuse without being inhibited.When λ/D =3,the separation zone is minimal.
作者
祝健
王晓东
马璐
康顺
ZHU Jian;WANG Xiao-Dong;MA Lu;KANG Shun(Key Laboratory of CMCPPE Ministry of Education,North China Electric Power University,Beijing 102206,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2019年第1期90-97,共8页
Journal of Engineering Thermophysics
基金
自然科学基金项目(No.51576065)
中央高校基本科研业务费项目(No.JB2015RCY05)
关键词
零质量射流
流动控制
湍流分离
大涡模拟
zero-net-mass-flux-jets
flow control
turbulent separation
large-eddy simulation
