Graduate Aeronautical Laboratories, Californ ia Institute ol Technology, Pasadena. CA 91125 The interaction of turbulent vortex rings that approach a clean water surface under various angles is experimentally investigated. The temporal evolution of the vortex rings with an initial Reynolds number of Re0 = 7500 is characterized by the Laminar/ turbulent transition and asymptotic relaminarization...

In magnetohydrodynamic (MHD) flows turbulence reduction occurs due to the Joule dissipation. It results in heat transfer degradation. In open channel flows, heat transfer degradation is also caused by the turbulence redistribution near the free surface. Both effects can be significant in fusion applications with low-conductivity fluids such as molten salts. In the present study, the ‘‘K–e’’ mod...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

Nearly all calculations and measurements of breaking waves assume the wave profiles and flow fields are two-dimensional. Though this assumption may be correct before the waves become turbulent, once transition to turbulent flow begins, the real flow becomes highly three dimensional. The threedimensional structure and motion of the free surface is important for the dynamics of the breaking proce...

In the present study, the conjugate turbulent free convection with the thermal surface radiation in a rectangular enclosure bounded by walls with different thermophysical characteristics in the presence of a local heater is numerically studied. The effects of surface emissivity and wall materials on the air flow and the heat transfer characteristics are the main focus of the present investigati...

In an open channel, the transformation from a supercritical flow into a subcritical flow is a rapidly varied flow with large turbulent fluctuations, intense air entrainment, and substantial energy dissipation called a hydraulic jump. New experiments were conducted to quantify its fluctuating characteristics in terms of free-surface and two-phase flow properties for a wide range of Froude number...

In turbulent free-surface flows, the deformation of the surface leads to air bubble entrainment and droplet projections when the turbulent shear stress is greater than the surface tension stress that resists to the interfacial breakup. These complex processes at the water-air interface have been the focus of extensive experimental, numerical and theoretical studies over last two decades and thi...

In this paper, a large-eddy simulation study of turbulent free surface flow over natural rough bed is presented. A three-dimensional multiphase model employed to the roughness effects on turbulence properties and dynamics. The governing equations have been discretized using finite volume method, with Cartesian cut-cell method being implemented deal precise scanned gravel topography deformable c...