This DNS study is focused on the structure of turbulence in a boundary layer. First, it is not appropriate to call the turbulent flow as a “random” motion. Any mean flow like Blasius solution, which is a Navier-Stokes solution, added by white noise or random perturbation would be rejected by Navier-Stokes equations and the perturbation will be damped quickly. The governing Navier-Stokes equatio...

In high-speed aerodynamics, shockwave/turbulent boundary layer interactions (STBLIs) can be responsible for design-limiting thermal and pressure loads (Dolling 2001). Additionally, when experienced in the inlet/isolator systems of ramjets and scramjets, separation and flow unsteadiness caused by STBLI can lead to additional blockage effects which may affect operability margins to engine unstart...

André Thess∗1, Dmitry Krasnov1, Thomas Boeck1, Egbert Zienicke1, Oleg Zikanov2, Pablo Moresco3, and Thierry Alboussière4 1 Department of Mechanical Engineering, Ilmenau University of Technology, P.O. Box 100565, 98684 Ilmenau, Germany 2 Department of Mechanical Engineering, University of Michigan Dearborn, Dearborn MI 48128-1491, USA 3 School of Physics and Astronomy, The University of Manchest...

The small vortex generation is a key issue of the mechanism for late flow transition and turbulence generation. It was widely accepted that small length vortices were generated by large vortex breakdown. According to our recent DNS, we find that the hairpin vortex structure is very stable and never breaks down to small pieces. On the other hand, we recognize that there are strong positive spike...

The long term goal of this work is to develop a fundamental understanding and predictive capability of the underlying physics of the interaction of nonlinear internal waves (NLIWs) with the continental shelf seafloor over a broad range of environmental conditions. We are particularly interested in how such interactions impact underwater optics and acoustics and shelf energetics and ecology by s...

A number of remote-sensing wind-measuring instruments, such as LIDAR and radar wind profilers, have been set up in the vicinity of the Hong Kong International Airport (HKIA) for monitoring of low-level windshear and turbulence. The combined usage of wind data from a radar wind profiler and boundary layer temperature profiles from a ground-based microwave radiometer in turbulence application is ...

Most of the ocean kinetic energy is contained in the large scale currents and the vigorous geostrophic eddy field, at horizontal scales of order 100 km. To achieve equilibrium the geostrophic currents must viscously dissipate their kinetic energy at much smaller scale. However, geostrophic turbulence is characterized by an inverse cascade of energy towards larger scale, and the pathways of ener...

An arrangement of boundary conditions is described and demonstrated that facilitates the large-eddy simulation (LES) of inhomogeneous boundary layers such as internal boundary layers. In addition to the domain where the internal boundary layer develops, the method requires a section of domain over the upwind surface that is of the order of 10 boundary layer thicknesses and thus similar in size ...