The wall-shear stress (WSS) fluctuations in the interaction of an oblique shock wave with a flat-plate turbulent boundary layer are investigated by means direct numerical simulation (DNS) at Mach 2.25. results agree very well previous experiments and DNS data terms turbulence statistics, wall pressure, skin friction. fluctuating WSS characteristics, including probability density function (PDF),...

Direct numerical simulations are extended to see the effects of time-periodic blowing frequency from a spanwise slot on a turbulent boundary layer. The time-periodic blowing frequency is given in a range 0≤f≤0.08 at a fixed blowing amplitude of A=0.5. The effects of the blowing frequency are scrutinized by examining the phaseor time-averaged turbulent statistics. A most effective blowing freque...

The study of flow and heat transfer over rotating circular disks is of great practical importance in understanding the cooling of rotatory machinery such as turbines, electric motors and design and manufacturing of computer disk drives. This paper presents an analysis of the flow and heat transfer over a heated infinite permeable rough disk. Boundary-layer approximation reduces the elliptic Nav...

The HYLIFE-II conceptual design uses arrays of high-speed oscillating and stationary slab jets, or turbulent liquid sheets, to protect the reactor chamber first walls. A major issue in thick liquid protection is the hydrodynamic source term due to the primary turbulent breakup of the protective slab jets. During turbulent breakup, drops are continuously ejected from the surface of turbulent liq...

Numerical studies of internal wave reflection from sloping boundaries are presented. Previous work (Slinn and Riley, 1996, 1998a, 1998b, 1999) has restricted attention to internal waves that approach the bottom slope in a plane normal to the boundary (normal incidence). This work extends the scope of the three-dimensional time-dependent numerical experiments to examine internal waves that appro...

The mechanism behind the collapse of turbulence in the evening as a precursor to the onset of the very stable boundary layer is investigated. To this end a cooled, pressure-driven flow is investigated by means of a local similarity model. Simulations reveal a temporary collapse of turbulence whenever the surface heat extraction, expressed in its nondimensional form h/L, exceeds a critical value...

A laminar boundary layer separates in a region of adverse pressure gradient, undergoes transition, and finally the turbulent boundary layer reattaches, forming a laminar separation bubble (LSB). Laminar-turbulent transition within such a LSB is investigated by means of Laser-Doppler-Anemometry (LDA), Particle Image Velocimetry (mono PIV and stereoscopic PIV (SPIV)) and direct numerical simulati...

In this paper, we study the influence on the ring-like vortex structure in MVG controlled supersonic ramp flow by different inflow conditions. In front of the MVG, three turbulent inflow profiles with different boundary layer thickness are generated as the inflow. From the shape factors, we can see that these inflows in front of the MVG are fully developed turbulent. It is found that the inflow...