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Errors when running study - Double Pipe HX

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Hi all. I'm very new to COMSOL, and tried to model this file off of one of the included COMSOL modules. I'm trying to solve a double pipe heat exchanger problem, which worked fine with the module until I used steam as the fluid in the inner pipe, then I began to get a lot of errors.

After that, I made my own file, copying the module but only including what seemed absolutely necessary for a temperature vs length study, yet I receive the same errors when I try to use steam in the inner pipe.

Can anyone help?

Here are the errors:

  • Feature: Stationary Solver 2 (sol1/s2) Division by zero.
  • Function: / Failed to evaluate variable.
  • Variable: comp1.nitf2.vhNS_lin Failed to evaluate expression.
  • Expression: nojac((1.4142135623730951455^(1-shapeorder(comp1.u2)))*max(comp1.nitf2.vhNS_lin-comp1.nitf2.vhNS_quad,0)) Failed to evaluate variable.
  • Variable: comp1.nitf2.vhNS Failed to evaluate temporary symbolic derivative variable.
  • Variable: comp1.nitf2.crosswindnitf@VDN${test@114} Failed to evaluate expression.
  • Expression: (((((-(comp1.spf2.gijzr((comp1.nitf2.vhNS+comp1.nitf2.vhNS_prime)(comp1.nitf2.rhocomp1.w2r))))-(comp1.spf2.gijzz((comp1.nitf2.vhNS+comp1.nitf2.vhNS_prime)(comp1.nitf2.rhocomp1.w2z))))2)pi)r)dvol_spatial Failed to evaluate Jacobian of expression.
  • Expression: (2comp1.nitf2.crosswindnitfpir)(dvol_spatial)


0 Replies Last Post May 4, 2020, 10:15 p.m. EDT
COMSOL Moderator

Hello N. Stevens

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