Kinetic equations modeling the behavior of the velocity probability density function sPDFd in homogeneous anisotropic decaying turbulence are hypothesized and their implications for return-to-isotropy are investigated. Anisotropic turbulent decay is a parametrically simple but theoretically complex turbulent flow that is dominated by nonlinear interactions. The physical implications of the Bhat...

GASFLOW-MPI is a scalable CFD software solution used to predict fluid dynamics, conjugate heat and mass transfer, chemical kinetics, aerosol transportation and other related phenomena. The generalized 3-D transient, compressible Navier-Stokes equations for multispecies are solved. It has been widely used to analyze safety problems in nuclear engineering. Turbulence models based on the ReynoldsA...

In this paper, we derive a general relationship for the turbulent Prandtl number Pr t for homogeneous stably stratified turbulence from the turbulent kinetic energy and scalar variance equations. A formulation for the turbulent Prandtl number, Pr t , is developed in terms of a mixing length scale LM and an overturning length scale LE , the ratio of the mechanical (turbulent kinetic energy) deca...

Accurate predictions of the sea state–dependent air–sea momentum flux require a thorough understanding of the wave boundary layer turbulence over surface waves. A set of momentum and energy equations is derived to formulate and analyze wave boundary layer turbulence. The equations are written in wavefollowing coordinates, and all variables are decomposed into horizontalmean, wave fluctuation, a...

turbulence structure on the gas side of a wavy stratified flow was experimentally investigated in a near horizontal 18.7 cm (h) 10 cm (w) 5.5m (l) rectangular duct.by applying the variable interval time averaging (vita) technique to the hot wire anemometer measurements frequency of occurrence of turbulent events were detected near the air-water interface. experimental results showed that freque...

the present study is concerned with measuring and simulating soot formation and combustion in turbulent liquid fuel spray flames. soot concentrations inside the combustor are measured by filter paper technique. the simulation is based on the solution of the fully-coupled conservation equations for turbulent flow, chemical species kinetic modeling, fuel droplet evaporation and combustion and soo...

Energy equation for turbulent flow in a rotating system was derived in terms of second order correlation tensors, where the correlation tensors were functions of space coordinates, distance between two points and time. To reveal the relationship of turbulent energy between two points, one point was taken as origin of the coordinate system. Due to rotation, the Coriolis force played an important...

We discuss hydrostatic models of galaxy clusters in which heat diffusion balances radiative cooling. We consider two different sources of diffusion, thermal conduction and turbulent mixing, parameterized by dimensionless coefficients, f and αmix, respectively. Models with thermal conduction give reasonably good fits to the density and temperature profiles of several cooling flow clusters, but s...

The oodlesDST code is based on OpenFOAM software and performs Large Eddy Simulations of turbulent fluid flows. The code contains a number of specialized subgrid scale turbulence models and wall models. This report describes these models in sufficient detail to allow a new user of the code to make informed decisions regarding the use of these models for particular applications. An overview of th...

The efficacy of large-eddy simulation ~LES! with wall modeling for complex turbulent flows is assessed by considering turbulent boundary-layer flows past an asymmetric trailing-edge. Wall models based on turbulent boundary-layer equations and their simpler variants are employed to compute the instantaneous wall shear stress, which is used as approximate boundary conditions for the LES. It is de...