DNS OF ATTACHMENT -LI NE/CROSSFLOW BOUNDAR Y LAYER INSTABILITY IN SUPERSONIC SWEPT WIN G FLOWS
DNS OF ATTACHMENT -LI NE/CROSSFLOW BOUNDAR Y LAYER INSTABILITY IN SUPERSONIC SWEPT WIN G FLOWS
复制标题
超声速扫掠翼流中附着线/横流边界层的 DNS 不稳定性
DOI：
10.2514/6.2004-252
复制
发表时间：
2004
期刊：
影响因子：
2.5
通讯作者：
N. Dryden
中科院分区：
文献类型：
--
作者：
Steven E. Speer;X. Zhong;L. Gong;R. Quinn;N. Dryden
一种高阶激波拟合、有限差分、直接数值模拟（DNS）的纳维-斯托克斯计算机代码正在开发中。该代码是专门开发的工具，用于研究与超音速/高超音速气流经过掠翼/锥形机翼几何形状相关的附着线和横流边界层过渡机制。本文简要介绍了研究基本附着线和横流涡掠翼边界层不稳定机理的重要性，并讨论了采用DNS模拟方法研究这一问题的原因。本文将展示几种不同抛物线截面机翼前缘几何形状（前缘后掠角和机翼锥度比不同）对马赫数5.1 ai流的DNS模拟的初步结果。还将显示非定常接受度模拟的初步结果，其中平均流动解是由在超音速流动中扫掠抛物面前缘形成的弓形激波前面的自由流中引入的驻声波或涡量波激发的。对于超声速/高超声速飞行器设计者来说，能够使用解析或计算方法准确预测实际三维几何形状的层流-湍流边界层（B.L.）过渡位置是非常理想的。表面摩擦阻力和表面加热速率是需要准确预测的两个重要参数，第一个是考虑范围性能，第二个是通过设计适当的热保护系统来确保车辆安全，该系统能够处理强烈的表面加热，但又足够轻，不会对车辆的可用有效载荷产生太大影响。表面摩擦和表面加热速率都取决于车辆表面附近边界层的类型。层流边界层比湍流边界层产生更小的表面摩擦和更低的表面消耗率。
A high -order shock -fitting, finite -difference, direct - numerical -simulation (DNS) Navier -Stokes computer code has been under development. The code has b een developed specifically as a tool for investigating the attachment -line and crossflow boundary layer transition mechanisms associated with supersonic/ hypersonic airflows past swept/tapered wing geometries. This paper briefly introduces the importance o f studying the fundamental attachment -line and crossflow vortice swept -wing boundary layer instabilities mechanisms and discusses the reasons for approaching the problem using DNS simulations. Preliminary results from several DNS simulations of Mach 5.1 ai rflow about various parabolic cross -section wing leading edge geometries, differing in leading edge sweep angle and wing taper ratio, will be shown. Also to be shown are initial results from unsteady receptivity simulations where the mean flow solution is excited by a standing acoustic or vorticity wave introduced in the freestream ahead of the bow shock created in front of a swept parabolic leading edge in supersonic flow. GENERAL INTRODUCTION For the supersonic/ hypersonic air -vehicle designer being able to predict accurately using analytical or computational methods the laminar -turbulent boundary layer (B.L.) transition locations about practical 3 -D geometries is extremely desirable. Skin friction drag and surface heating rates are two important paramete rs which need to be predicted accurately, the first for range performance considerations and the second to insure vehicle safety by designing an appropriate thermal protection system capable of handling the intense surface heating, which yet will be light enough not to impact the vehicles usable payload very much. Both the skin friction and the surface heating rates are dependent on the type of boundary layer near the vehicles surface. A laminar boundary layer produces less skin friction and lower surface h eating rates than a turbulent boundary layer.