钝体头部“逾越”型转捩的直接数值模拟
DNS of the Blunt Nose Bypass Transition
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摘要: 通过直接数值模拟,研究了钝体头部边界层“逾越”型转捩的问题。在计算上,利用高阶紧致差分格式和高分辨率的无反射边界条件,求解全N-S方程,并将局部有限幅值扰动直接引入到钝体头部的曲面边界层中。摈弃了目前国际上通常采用的周期边界条件,以及以平板代替曲面的做法。结果表明:流场转捩的发生与一种类似“发卡”状的拉伸结构出现有关,而国外的计算结果中并未发现这一结构。此外,流场的失稳过程和物理图像也存在较大差异。这说明国外目前的做法和结论是值得商榷的。同时,模拟的结果也说明,这种方法对研究大扰动转捩来说是一条行之有效的途径。Abstract: Bypass transition from laminar to turbulent flow in boundary layer of a blunt nose was studied by means of Direct Numerical Simulation(DNS).The full Navier-Stokes equations were numerically solved,using high-order compact finite difference schemes and high-resolution non-reflecting boundary conditions.The local finite amplitude disturbances were directly introduced into the boundary layer of a curved surface.The common calculating methods,i.e.using periodic boundary condition and curved surface replaced by flat plane,were discarded.The present result shows that transition in the flow field is correlated with the appearance of a kind of elongated structure,which is similar to a "hair-pin".This structure has not been found in other literatures.In addition,there are a lot of differences both in the instable process and in the structure pattern.The present results point out the direction of generalization of the observed transition mechanism to localized disturbances in wall bounded shear flow.
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Key words:
- aerospace propulsion system /
- numerical simulation /
- blunt body /
- bypass transition
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[1] 袁湘江,黎作武.钝头体超音速边界层稳定性研究[R].天津市第一届青年科技工作者会议,1995. [2] 袁湘江,周恒,赵耕夫.超音速、高超音速球锥绕流的边界层稳定性特点初探[J].空气动力学学报,1999,17(1):98~104.Yuan Xiangjiang,Zhou Heng,Zhao Genfu.Stability Characteristics of the Boundary Layer of an Axisymmetric Blunt Nosed Cone in the Supersonic and Hypersonic Flow[J].ACTA Aerodynamics Sinica,1999,17 (1):98~104. [3] Widhopf G F,Hall R.Transitional and Turbulent Heat Transfer Measurements on a Yawed Blunt conical Nosetip[J].AIAA J.1972,10:1318~1325. [4] Swain R B.Aerodynamics of Reentry Vehicles with Asymmetric Nosetip Shape Change[R].AIAA Paper 77~782. [5] Breuerl K S,Landahl M T.The Evolution of a Localized Disturbance in a Laminar Boundary Layer.Part Ⅱ -Strong Disturbance[J].J.Fluid Mech.1990,220:595 ~ 621. [6] Henningson D S,Lundbladh A,Johansson A V.Mechanism for Bypass Transition in Wall-Bounded Shear Flows[J].J.Fluid Mech.,1993,250:169~207. [7] Laurien E.Numerical Investigation of Laminar-Turbulent Transition on Re-Entry Capsules[J].Journal of Spacecraft and Rockets,1996,33(3):313~318. [8] 袁湘江,周恒.考虑流向曲率和压力梯度的可压缩边界层稳定性分析[J].空气动力学学报,1998,16(3):276~281.Yuan Xiangjiang,Zhou Heng.Stability of Compressible Boundary Layers with Streamwise Curvature and Pressure Grads[J].ACTA Aerodynamics Sinica,1998,16 (3):276 ~281. [9] Poinsot T J,Lele S K.Boundary Conditions for Direct Simulations of Compressible Viscous Flows[J].J.Comput.Phys.,1992,101:104~129. [10] 袁湘江,桂业伟.适于超音速流动的高精度高分辨度算法研究(阶段报告)[R].CARDC-20010015,绵阳:中国空气动力研究与发展中心. [11] 袁湘江,桂业伟.高精度数值方法与非线形扰动研究(阶段报告)[R].NLCFD-200305,北京:国家计算流体力学实验室.
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