Create expression in CFD Post including velocity as denominator

- August 13, 2019 at 2:53 pm
  
  Chris1opher
  Subscriber
  
  Dear all,
  
  I want to plot contours of a local dimensionsless number in cfd post.
  For that purpose I created an expression in CFD-Post.
  I use this expression in a variable and then plot the contours of that variable.
  A simple example like 1/Velocity as the expressions results in the following error:
  
  'Vertex' values for Variable 'testvariable' do not exist on Geometry /DATA READER/CASE:Case FFF/BOUNDARYeriodic 1.
  
  There is no Error when I only write "Velocity" in my expression, but as soon as Velocity is in the denominator it is not working anymore.
  
  Can u tell me how to use Velocity in the expression?
  
  Kind regards
  Christopher
- August 13, 2019 at 3:42 pm
  
  Chris1opher
  Subscriber
  
  I think I found the reason why it is not working.
  Velocity is saved as a vector and using 1/vector might not be defined.
  Is that right and is there any possibility to normalize the vector to gain a scalar?
- August 13, 2019 at 4:09 pm
  
  Rob
  Ansys Employee
  
  You can use velocity magnitude (can't remember the macro) but also remember it'll be zero in some places so the expression value may get rather high.

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