We propose a method for building a statistical model for the structural uncertainties in the k − ω turbulence model. An inverse RANS problem is solved for a collection of randomly generated geometries to determine the turbulent viscosity that produces the flow field closest to that predicted by direct numerical simulation (DNS). A statistical model of the uncertainty in the turbulent viscosity ...

This paper presents a computational study of the separated flow in a planer asymmetric diffuser. The steady RANS equations for turbulent incompressible fluid flow and six turbulence closures are used in the present study. The commercial software code, FLUENT 6.3.26, was used for solving the set of governing equations using various turbulence models. Five of the used turbulence models are availa...

In the present work are presented results from numerical simulations performed with the ANSYS-CFX code. It is studied a radial diffuser flow case, which is the main academic problem used to study the flow behavior on flat plate valves. The radial flow inside the diffuser has important behaviors such as the turbulence decay downstream and recirculation regions inside the valve flow channel due t...

Aims. To understand the dynamics of stellar interiors, we study the effect of rotation on turbulence. Methods. We consider turbulence induced by an arbitrary forcing and derive turbulence amplitude and turbulent transport coefficients (turbulent viscosity and diffusivity), first by using a quasi-linear theory and then by using a multi-scale renormalisation analysis. Results. With an isotropic f...

The theory of compressible MHD (e.g., Alfvénic) turbulence has been a topic of interest for some time [1]. Alfvén wave turbulence presents several novel challenges, due to the fact the k–ω selection rules preclude three Alfvén-wave resonance. Thus, in incompressible MHD, two Alfvén waves can interact only with the vortex (i.e., eddy) mode. Compressibility relaxes this constraint by allowing int...

The chance of developing lung cancer is increased through being exposed to cigarette smoke illustrated by studies. It is vital to understand the development of particular histologic-type cancers regarding the deposition of carcinogenic particles, which are present in human airway. In this paper, the mass transfer and deposition of cigarette smoke, inside the human airway, are investigated apply...

Film-cooling flows are characterized by a row of jets injected at an angle from the blade surface or endwalls into the heated crossflow. The resulting flowfield is quite complex, and accurate predictions of the flow and heat transfer have been difficult to obtain using traditional two-equation turbulence models employed with ReynoldsAveraged Navier–Stokes (RANS) solvers. Recently, a four-equati...

The shape of the air flow in the interior is heavily influenced by the air distribution system and the way air enters and exits. By numerically simulating flow by computational fluid dynamics, one can determine the flow pattern and temperature distribution and, with the help of the results, provide an optimal design of the air conditioning system. In this study, a chamber was first constructed ...

The prediction accuracies of partially-averaged Navier-Stokes model and improved shear stress transport k-ω turbulence model for simulating the unsteady cavitating flow around the hydrofoil were discussed in this paper. Numerical results show that the two turbulence models can effectively reproduce the cavitation evolution process. The numerical prediction for the cycle time of cavitation incep...