We present a new model of turbulence spreading in magnetically confined plasma. A basic question in turbulence spreading is how to sustain finite amplitude fluctuations in a stable subcritical region, where linear dissipation of the turbulence is strong? The answer to this question relies on a consistent treatment of mesoscale temperature profile corrugation and microscale turbulence. We argue ...

A number of numer~cal simulations of rack storage fires have been carr~ed out, with various fuel types and burner outputs. Both the standard buoyancy-modified k E turbulence model and a recently developed turbulence model which significantly improves the consideration of the buoyancy effect on turbulence and turbulent transport, were used to study the turbulence of the buoyant flow. The flamele...

in this paper, considering the importance of incoming flow turbulence intensity into combustion chamber, tripping wire effect on the flow wake has been experimentally investigated within a linear compressor cascade. to do this, two wires were implemented along each blade and their effects on average velocity, turbulence intensity and vortices frequencies at reynolds number 45500 were accurately...

The results are reported of an experimental investigation of turbulent flow through a plane sudden expansion of expansion ratio R=D/d=4 and aspect ratio A= w/h=5.33. It is well known that plane sudden expansions with R greater than 1.5 produce asymmetric flows and this was again seen in this study. The literature for the asymmetric situation (R>1.5) is surprisingly limited and only axial veloci...

We propose a consistent lattice Boltzmann equation (LBE) with baroclinic coupling between species and mixture dynamics to model the active scalar dynamics in multi-species mixtures. The proposed LBE model is directly derived from the linearized Boltzmann equations for mixtures and it has the following two distinctive features. First, it uses the multiple-relaxation-time collision model so that ...

This report presents the use of a time-marching threedimensional (3-D) compressible Navier-Stokes equation numerical solver with a one-equation turbulence model to simulate the flow fields developed along concave wall surfaces without and with a downstream extension flat wall surface. The 3-D Navier-Stokes numerical solver came from the NASA Glenn-HT code. The one-equation turbulence model was ...

This paper presents a way of modelling turbulence in multiphase flows within the context of the Reynolds-Stress Model. The model has been implemented in the general-purpose unstructured finite volume code Fluent V6. Two multiphase turbulence approaches were considered: mixture and dispersed models. The mixture model solves the Reynolds-stress transport equations on the mixture level only. The d...

We propose a consistent lattice Boltzmann equation (LBE) with baroclinic coupling between species and mixture dynamics to model the active scalar dynamics in multi-species mixtures. The proposed LBE model is directly derived from the linearized Boltzmann equations for mixtures and it has the following two distinctive features. First, it uses the multiple-relaxation-time collision model so that ...

Optimal control of enclosed environment requires detailed information of air distribution that could be obtained by numerically solving Navier-Stokes equations with a suitable turbulence model. This investigation evaluated the performance of eight turbulence models for transient airflow in enclosed environment using experimental data obtained in a room. The study used the room to create three c...

Lateral intake is a structure constructed next to a main channel to divert part of the flow within the channel. The separated area of the flow in the entrance of intake channel has no effect on flow discharge while reduces the effective cross-sectional area of the intake, as well as the bed load, which enters the intake due to low velocity flow deposits in this area. Thus, knowing the dimension...