The unsteady separated turbulent flow around an oscillating airfoil pitching in a sinusoidal pattern in the regime of low Reynolds number is investigated numerically employing the URANS approach with two advanced turbulence models, namely the RNG kmode and Transition SST model, and the DES approach based on the SST kmodel. A comparison with experimental data shows that the SST kbased D...

In the inertial range of fully developed turbulence, we model the vertex network dynamics by an iterated unimodular map having the universal behavior. Inertial range anomalous scaling for the pair correlation functions of the velocity and the local energy dissipation is established as a consequence of the chaotic behavior of the unimodular map when the Feigenbaum attractor looses stability. The...

A numerical simulation has been performed of the disturbed flow through and over a twodimensional array of rectangular buildings immersed in a neutrally stratified deep roughwalled turbulent boundary-layer flow. The model used for the simulation was the steady-state Reynolds-averaged Navier-Stokes equations with linear and non-linear eddy viscosity formulations for the Reynolds stresses. The ed...

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...

A simple, quasi-steady, one-dimensional, vertical (1DV) model of unsteady sheet flow is presented. The central aim is to provide greater realism in the near-bed, high-concentration layer, than is possible using models based on the classical referenceconcentration approach. This is achieved by tracking erosion and deposition at the bottom of the mobile sediment layer in relation to the amount of...

A modified version of Chandrasekhar's equation is derived with the aid of Karman 's energy transfer process for the decay of hydromagnetic turbulence in the limiting case of zero viscosity and infinite electrical conductivity. I t is found that the asymptotic behaviour of self-preserving solutions of the aforesaid equations leads to F(k, t) m k4, (c = 2/7), G(k, t) fa k6, (c = 2/9) as and F(k,t...

  In this study, fluid flow and energy separation in a micro-scale Ranque-HilschVortex Tube are numerically investigated. The flow is assumed as 2D, steady,compressible ideal gas, and shear-stress-transport SST k-W is found to be a bestchoice for modeling of turbulence phenomena. The results are in a good agreementwith the experimental results reported in the literature. The results show that f...

Numerical simulations have been undertaken for the benchmark problem in a Square cavity by using computational fluid dynamics software. This work aims at discussing the fundamental numerical and computational fluid dynamic aspects which can lead to the definition of the following meshing methods and turbulence models. The meshes used for the simulation are hexahedral, hexahedral cell with near ...

This study examines the thermal performance of a two-dimensional borehole system, featuring U-shaped pipe embedded in porous soil, through application computational fluid dynamics. The investigation encompasses 24 cases, assessing impact various factors such as soil conductivity (k = 1.5, 1.84, 2 W/mK), average temperature (T 280-285 K), and moisture content (10%-55%) on ice formation heat tran...