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I am simulating an axial turbine, I tried different mesh topologies and all give me almost the same number. In fact, Boundary layer is not captured well, Reynolds number is equal to $4.4 \times 10^5$ and according to mentioned formula in the following link, I computed $y_1$ (First cell height) by using $y^+ = 30$ and $y^+ = 60$.

But in the two cases($y^+=30$ and $y^+=60$), the boundary layer is not captured well (Why?). In the other words, according to the following figure, there is no adjacent wall. And also, I studied the following link:

For this reason, performance parameters are not validated well. In fact, there is a difference with the experimental value. This difference is not big but it is not good! I think that it is difficult to capture BL by using low Re number turbulence model (for example, $k-\epsilon$ turbulence model).

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  • $\begingroup$ Please set out explicitly what you mean by BL, RE, y, Y, Re, K-e. And incorporate the relevant equation from those links into your post: questions need to contain all the relevant information, not just links to information elsewhere. $\endgroup$ – 410 gone Nov 2 '15 at 7:06
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    $\begingroup$ @EnergyNumbers Terms like BL (Boundary Layer) are common for anyone working in fluid mechanics and Fluent. $\endgroup$ – Mahendra Gunawardena Nov 2 '15 at 10:45
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    $\begingroup$ @MahendraGunawardena that's irrelevant. The point is to create a question body that will be meaningful to a wide audience, and to create sufficient text for people doing searches to find the question. $\endgroup$ – 410 gone Nov 2 '15 at 11:01
  • $\begingroup$ @EnergyNumbers I agree with Mahendra. There's no point trying to widen the audience for a relatively sophisticated fluids question to attract readers who aren't familiar with basic fluids concepts. $\endgroup$ – Air Nov 2 '15 at 23:26
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    $\begingroup$ @Air but if you were googling a question on boundary layers, you'd search for "boundary layer", not "bl", because "bl" would give you millions of useless results. $\endgroup$ – 410 gone Nov 4 '15 at 7:20

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