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Attempt to evaluate real square root of negative number. - Function: sqrt Failed to evaluate variable. - Variable: comp1.mf
Posted 9 apr 2020, 06:22 GMT-4 Fluid & Heat, Heat Transfer & Phase Change, Computational Fluid Dynamics (CFD) Version 5.5 2 Replies
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Hello Everyone,
I am doing a simulation on laser keyhole welding and I am getting the following error: Attempt to evaluate real square root of negative number. - Function: sqrt Failed to evaluate variable. - Variable: comp1.ṁ (errors related to this ṁ variable: please see the attached figure. I have encircled this variable with red pen) I am trying to remove this error like last month. This "ṁ" variable (mass flow rate) has only one parameter in the square root which is Temperature (T) and I even put a boundary condition as T>Tvap. Smoothed the material properties. Refined the mesh. But no luck in solving this error. I request to all elite members to comment on it. I would be grateful to you. Thank you.
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Hello,
If you are absolutely certain that your square root argument is greater than zero, you can try adding "eps" to the square root argument. There is a possibility that if the argument is zero, it will be numerically taken as negative, so that adding a very small number could fix this issue. Let me know if this helps.
Cheers,
Alex
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Thank you Alex for your input.
When I added eps inside the sqrt term, it made it run the simulation in the beggining but after a while, same error shown.
I think, my initial condition or BC has some problems. I am going to change some conditions and update you the results.
What are you working on ? I am modelling a laser keyhole weldings phenomenon.
Regards, Akash Meena