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sajad_abasi September 14, 2011 19:44

"du/dy" by "CEL" expression
hi all.
i want to calcuate derivative of u velocity with respect to normal cordinate.i mean that i want "du/dy".
is it possible to use "CEL" expression to obtain this quantity?
best regards.

ghorrocks September 14, 2011 23:25

u.Gradient y

sajad_abasi September 18, 2011 10:53

hi Glenn
can i use this formula "u.gradiant y" in pre processing?
i want to set it as a boundary condition.i mean that my B.C is in dependent of "du/dy".
so can i define CEL expression and use it as B.C?

best regards.

ghorrocks September 18, 2011 18:24

Can you explain what you are doing? Openings and outlets already set du/dy (normal to the interface) to zero.

sajad_abasi September 19, 2011 10:07

i want to set slip velocity condition on walls and the formula is the maxwell-smoluchowski first order slip condition in this form:
so i need to have u gradient with respect of y on walls.
is it possible to do this with writing "CEL" expression?

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