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Surface Yplus of a Cylinder

Hello everyone,

I want to verify the surface y-plus of transient flow over cylinder. There are 2 situation of the Boundary (BL) mesh:

A: 1st BL height with y+ = 1 (viscous layer)
B: 1st BL with y+ = 50 (turbulent layer)

My question is: what is the expected y+ value of the cylinder's skin/surface during post processing for case A and B? Should it falls at the same region as preprocessing?

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ydigit

I do not completely understand your question, but if it concerns consistency between y+ calculated at pre and y+ visible in post, they should be somewhat consistent. Note that cylinder will have high velocity and low velocity flow, so the y+ is not going to be constant all round it (assuming BL in constant).
You should be able to visualize the Surface Y plus in HyperMesh CFD Post processing or HyperView or SimLab

Nazrin

I do not completely understand your question, but if it concerns consistency between y+ calculated at pre and y+ visible in post, they should be somewhat consistent. Note that cylinder will have high velocity and low velocity flow, so the y+ is not going to be constant all round it (assuming BL in constant).
You should be able to visualize the Surface Y plus in HyperMesh CFD Post processing or HyperView or SimLab

For example, case B,

Mesh 1st BL height of cylinder surface is 50 that falls in log-law region in pre-processing.

1. So, during post-processing, should I expect the surface y+ of the cylinder in range of 30-300 (log law region)?

2. What if the range falls in range of 2-150 (which combination of viscous, buffer and log law region)? Is it wrong?

acupro

For example, case B,

Mesh 1st BL height of cylinder surface is 50 that falls in log-law region in pre-processing.

1. So, during post-processing, should I expect the surface y+ of the cylinder in range of 30-300 (log law region)?

2. What if the range falls in range of 2-150 (which combination of viscous, buffer and log law region)? Is it wrong?

The turbulence models in AcuSolve are valid through the entire boundary layer - from Y+ = 1 to Y+ = 300. Lower Y+ means more of the boundary layer profile is calculated with more mesh and higher computational cost, higher Y+ means more of the boundary layer profile is modeled.