Turbulent Jet Setup and Solution

Background

The k-ε model solves the RANS - Reynolds Averaged Navier Stokes model, which solves time-averaged Navier Stokes equations.Two additional equations for the turbulent kinetic energy k, and the turbulent dissipation ε, account for the turbulent properties, using the turbulent viscosity to calculate the additional Reynolds stress terms that emerge when time averaging the Navier Stokes equations. It is one of the more widely used models, particularly for flows with small pressure gradients. 

The following empirical formulas are useful in defining this model. I is the turbulent intensity,

 is the hydraulic diameter, and d is the jet diameter. 

,   

,  

,  

Setup

Use the same case and data files as you downloaded in the Laminar setup for the geometry and mesh. 

Now, set up the k-ε model for turbulence. In Solution Setup-Models, double click the previous "Viscous-Laminar" option to open the dialogue. Select the "k-epsilon (2eqn)" model for turbulence. Leave the model constants the same as defined in the dialogue below; these values have been refined to constraints of the model and are typically not varied. Press OK.

 
In the Materials dialogue. change the viscosity for a higher Reynolds number (

).

Go to Step 5: Turbulent Jet Results

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