In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...

This study aims to explain and elaborate a new model for the business environmental hostility in small and medium enterprises in the science and technology park in Kermanshah (Iran). The research method is a mixed method. Content analysis was used in the qualitative part, and a confirmatory factor analysis was used in the quantitative section. In the qualitative section for the environmental ho...

A non-premixed coaxial oxy-fuel turbulent flame was studied numerically with standard and realizable k-ε turbulence model and a comparison was made between them. The governing equations were solved by finite volume approach and were discretized using the second order upwind scheme. The presumed β-PDF model was applied to model turbulence-combustion interaction. The discrete ordinate radiation h...

in this study, changes in speed and turbulence intensity in the wake of a peugeot model and the drag coefficient changes with increases vehicle speed in unsteady flow measured and evaluated. the blow open circuit wind tunnel to simulate fluid flow is used. disturbances and nominal maximum speed of the device, respectively is, 30 m / s and 0.01%. has been continuously increasing speed by an inve...

One of the newest of viscoelastic RANS turbulence models for drag reducing channel flow with polymer additives is studied in different flow and rheological properties. In this model, finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model is used to describe the viscoelastic effect of polymer solution and turbulence model is developed in the k-ϵ-(ν^2 ) ̅-f framework. The geome...

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 ...

intake system design as well as inlet ports and valves configuration is of paramount importance in the optimal performance of internal combustion engines. in the present study, the effect of inlet ports design is investigated on om-457la diesel engine by using a cfd analysis and the avl-fire code as well. a thermodynamic model of the whole engine equipped with a turbocharger and an intercooler ...

In this study, modeling of a fuel jet which has been injected by high pressure into a low-pressure tank are investigated. Due to the initial conditions and the geometry of this case and similar cases (like CNG injectors in internal combustion engines (ICE)), the barrel shocks and Mach disk are observed. Hence a turbulence and transient flow will be expected with lots of shocks and waves. Accord...

In the following paper, the effects of a choked jet exhausted from the base of a non-lifting body on its total and base drags at sub-sonic and transonic regimes has been numerically investigated. Having surveyed the results of some turbulence models and after comparing with experimental results, an appropriate turbulence model i.e. SST K-?, has been chosen and this model has been used in the su...