CBET-EPSRC: Transition and Turbulence in Compressible Boundary Layers Subjected to Concave Surface Curvature

凹形表面上的可压缩边界层流动以Gortler涡为特征，在许多流体工程应用中普遍存在，例如涡轮机叶片、高速飞机机翼和超音速风洞中的喷嘴。这项工作的总体目标是数值研究空间发展的可压缩边界层凹表面，从层流制度到完全湍流制度，并推进基本的理解和预测Gortler涡诱导的过渡和空间发展的壁面有界的湍流受到凹表面曲率在超音速马赫数。这项研究将由英国和美国的研究人员联合进行，他们可以完美地互补。边界层物理的详细研究还将与大涡模拟和雷诺平均纳维尔-斯托克斯（RANS）相结合，以评估亚网格尺度和RANS模型对Gortler涡为主的过渡流的性能。由于RANS模型缺乏包括上游历史对边界层扰动的影响所必需的物理基础，DNS数据将与基于RANS的预测进行比较，以评估初始湍流区的计算质量。这些数据也可用于评估LES再现不同LES过滤器特性的过渡区的能力。在研究工作的同时，将开展各种教育活动，以展示和灌输网络物理学发现的兴奋在各级学生，以及准备在高速流动和先进的网络基础设施训练有素的劳动力。

Compressible boundary-layer flows over concave surfaces, characterized by Gortler vortices, are ubiquitous in a large number of fluid engineering applications, such as turbine blades, high-speed aircraft wings, and nozzles in supersonic wind tunnels. The overall objectives of this proposed work are to numerically investigate spatially developing compressible boundary layers over concave surfaces, from the laminar regime up to the fully turbulent regime, and to advance both the fundamental understanding and prediction of Gortler-vortex-induced transition and spatially developing wall-bounded turbulence subject to concave surface curvature at supersonic Mach numbers. The research will be conducted jointly by UK and US investigators who perfectly complement each other. The detailed study of boundary-layer physics will also be combined with large-eddy simulations and Reynolds-averaged Navier-Stokes (RANS) to assess the performance of subgrid-scale and RANS models for transitional flows dominated by Gortler vortices. Because RANS models lack the physical basis necessary to include the effects of the upstream history on boundary-layer disturbances, the DNS data will be compared with RANS-based predictions to assess the quality of the computation of the initial turbulent region. The data can also be used to evaluate the ability of LES to reproduce the transition zone for different LES filter characteristics. In conjunction with the research effort, a variety of educational activities will be undertaken to showcase and instil the excitement of cyberphysics discovery in students at all levels, as well as to prepare a highly-trained workforce in high-speed flows and advanced cyberinfrastructure.