Is there a good way to identify turbulence structures in a flow?
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One way to do this is by plotting isosurfaces of low pressure as well as isosurfaces of the so called Q criterion. The attached document describes of Q is defined and how it can be calculated from variables available in the res file: the Shear Strain Rate, and Velocity.Curl (vorticity). The attached Post session file creates an expression for Q (expression called Q Hunt), and creates a variable (Q Hunt Field) assigned to Q. More tools to help with the identification of turbulence structures are planned for version 12. This includes the calculation of the following scalar quantities that will be available for plotting: 1. Lambda 2 (negative). 2. Normal Eigen Helicity 3. Real Eigen Helicity 4. Stretched Swirling Strength 5. Swirling Discriminant 6. Swirling Normal 7. Swirling Strength 8. Swirling Vector 9. Velocity Gradient Invariant Q 10. Velocity Gradient Real Eigen Value 11. Vorticity |
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