Eddy Viscosity Concept & Turbulent Kinetic Energy Equation

Turbulence flow exhibits randomness but it is possible to approach them via statistical methods. It fluctuates in time and space. It is possible to do spatial and time averaging. In RANS approach, we time average the turbulent quantities to extract the mean flow properties from the fluctuating ones. Now, we have to find some way …

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Navier-Stokes Equation in Moving Reference Frame (MRF)

Reference: ANSYS Officials Most of the CFD applications consist of stationary objects around/inside which fluid will be flowing. So meshes are stationary. If the flow is incompressible, Incompressible Steady Navier-Stokes equations are solved. Very common applications are – Flow around Aerofoil, Flow inside Pipe. In both cases aerofoil and pipe are stationary hence meshes are stationary & …

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Wall Function: Boundary Layer Modelling Approach

Reference: aerospaceengineeringblog When the flow approaches a solid surface, a steep gradient would form due to the no-slip condition at the surface. This is known as Boundary Layer that develops near the solid surface in contact with the flow. The thickness of this boundary layer affects the wall heat flux and wall shear stress. In order …

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Classification of 2nd Order PDE in Fluid Flow Application

Partial Differential Equations based on their mathematical behavior can exhibit totally different solutions in the flow field. The different and unique behavior of PDEs depends on their characteristics. It is very important to study these characteristics of PDEs so that we can make an assessment of the kind of numerical method that should be applicable …

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