Computing turbulent convection

The turbulent flow will be computed if turbulence model is activated at least in one region and either Convection or Turbulent Convection is selected to be currently computed in CrysMAS.

Prerequisites

The computation of the turbulent flow requires any start solution. The temperature distribution without account of the turbulent convection should be calculated. This start solution should not necessarily fully converge.

A short run with the laminar gas flow should be done before the turbulence modeling begins. At the beginning of the laminar fluid flow calculation the edge values of the temperature in the gas region will be allocated. These values are used also in the turbulent gas flow.

Start computation

  1. Select the argon region in the drawing.

  2. Select Settings > Physical Phenomena.

    The Physical Phenomena dialog opens and indicates 1 region(s) selected.

  3. Set Turbulent Convection to Yes by clicking on the associated box, if it is not preselected.

  4. Click on Apply and Close.

  5. Select Turbulent Convection from the variable group list box in the tool bar.

    The default variable for visualizing results is turbulent_energy.

  6. Select Computation > Start Computation.

    or

    Click on the Start computation button   in the tool bar.

    You can follow the solving process in the status bar. When computing is finished, you can visualize the results.

    If the solving takes longer than you expected, you can stop the computation by clicking on the Stop computation button  .

Visualizing results

The variables of the turbulent flow can be shown by selecting them, as usual, from Turbulent Convection group. They are shown by isolines and/or by the colored filled polygons.

Showing turbulent energy 

Figure 67. Showing turbulent energy

Showing turbulent viscosity 

Figure 68. Showing turbulent viscosity

All variables which are distributed over the triangle by quadratic shape functions are visualized using additionally the variables allocated in the middles of the edges. In this case each triangle is subdivided into 4 sub-triangles virtually. The field distribution is assumed to be linear within each sub-triangle created by the middle points of the edges and the triangle corners