Roughness

[YJ]

Hello,

I am trying to assign a roughness value for a concrete wall of my model.

and I see on p89 the user guide that " The surface roughness (in meters) is set by ROUGHNESS on SURF."

I am wondering if this roughness is absolute roughness used to calculate pressure loss using moody chart? 

[Randy McDermott]

It is absolute roughness. It has dimensions of meters.

Sent from my iPhone

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[YJ]

Dear Randy,

Then  's' in p32  and epsilon in p 95 Technical guide are the same roughness, right?

Thanks you so much

YJ

[Randy McDermott]

Yes.  Sorry for the inconsistency.  This is a case where we have two different authors each trying to maintain a degree of consistency with the citation where the formula is found.

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