Calculating wall normal vector

ArtSimulatingLife · March 19, 2020, 11:39

Hello everyone,

I'm trying to calculate the wall normal vector in CFX to then use in a particle routine, I found an equation online that said: (Fluid.Wall Scale.Gradient X+Fluid.Wall Scale.Gradient Y+Fluid.Wall Scale.Gradient Z)/mag(Fluid.Wall Scale.Gradient)

But don't really understand what those values are, when you extract the wall scale gradient in a user function you get 9 numerical values out at each location as the format for gradients on a vector is (3,NLOC,3) and it says the first number is the number of gradient components and the second number is the number of tensor components, how do I use the values from CFX and manipulate them into the equation?

Opaque · March 19, 2020, 15:39

Have you tried using

Normal X,
Normal Y
Normal Z

variables instead?

March 19, 2020, 11:39	Calculating wall normal vector	#1
ArtSimulatingLife New Member John Join Date: Jan 2020 Posts: 12 Rep Power: 6	Hello everyone, I'm trying to calculate the wall normal vector in CFX to then use in a particle routine, I found an equation online that said: (Fluid.Wall Scale.Gradient X+Fluid.Wall Scale.Gradient Y+Fluid.Wall Scale.Gradient Z)/mag(Fluid.Wall Scale.Gradient) But don't really understand what those values are, when you extract the wall scale gradient in a user function you get 9 numerical values out at each location as the format for gradients on a vector is (3,NLOC,3) and it says the first number is the number of gradient components and the second number is the number of tensor components, how do I use the values from CFX and manipulate them into the equation?

March 19, 2020, 15:39		#2
Opaque Senior Member Join Date: Jun 2009 Posts: 1,880 Rep Power: 33	Have you tried using Normal X, Normal Y Normal Z variables instead? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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