Learning Forum

[지완 서]

I performed a turbulence simulation using RANS.

I want to analyze the y+ values at the boundary of the model.

Using the contour option, I can observe the turbulence - y+ values on the model boundary and by integrating along the boundary, I can obtain the average y+ value. 

Which value should I consider to be accurate, as the results differ?

Thansk :)

[Rob]

Integrating what along the boundary? 

[지완 서]

I integrated over the surface of the analysis model.

Thanks :)

[Rob]

You're asking why the integral and the average are different? The various surface reports are covered in https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v242/en/flu_ug/flu_ug_chp_report.html

[지완 서]

The specific question is as follows:

We can observe the y+ value through surface integral and contour in the turbulence section. I am curious why the two y+ values observed here are different.

The y+ value obtained through surface integral makes sense to me. It is calculated by summing the individual y+ values in each region and then dividing by the area.

However, when looking at the y+ value from the contour on the boundary surface of the model being analyzed, there is a significant difference in the values. This discrepancy is what I am curious about.

Finally, I would like to know which method of evaluating the y+ value is generally considered standard.

Thanks :)

[Rob]

Did you plot with node values on or off? The former will show some smoothing of the values, the latter the actual node (facet in this case) value.