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Overflow error

- March 26, 2019 at 4:52 am
  
  bigdawg12
  Subscriber
  
  Hi all. Attached is my mesh for flow over an airfoil. I can't seem to get a y+ value less that one, or even into the single digits. I can't even run a solution past 5 iterations. I've triple checked that I've set up the problem correctly with the proper boundary conditions and turbulence of interest. What seems to cause the "update failed for the Solution component in Fluid Flow (CFX). The solver failed with a non-zero exit code of : 2" error? I've even reconstructed the airfoil to go without quadrants and edge splitting, but even though I can run a solution, I can't get anything close to the experimental results.
- March 26, 2019 at 4:57 am
  
  Keyur Kanade
  Ansys Employee
  
  as ansys employees, we can not download attachments. please insert some images and explain issue in detail.
- March 26, 2019 at 5:59 am
  
  bigdawg12
  Subscriber
  
  Ok thanks!
- March 26, 2019 at 5:59 am
  
  bigdawg12
  Subscriber
  
  I get the following results, but still not sure on the mesh
- March 26, 2019 at 6:00 am
  
  bigdawg12
  Subscriber
  
  For the setup, I've initialized the inlet (the semi circle) with cartesian velocity components < 30 m/s, 0 m/s, 0 m/s >. I'm using the gamma theta model for transitional turbulence. I've set the top and bottom boundaries as openings with entrainment with 0 Pa relative pressure. I've set the inlet, to inlet with the <30,0,0>, and the outlet, to outlet with 0 relative pressure. I've also named the front face Sym1 and established a boundary condition of symmetry, and the back face as Sym2 as symmetry. I've also set the number of iterations to 10, but can't seem to get that far, and the convergence criterion to 1e-07.
- March 26, 2019 at 6:00 am
  
  bigdawg12
  Subscriber
  
  When I run the Solver, I check large problem and double precision with a memory allocation factor of 1.4.
- March 26, 2019 at 6:00 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:01 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:01 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:02 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:02 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:02 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 6:03 am
  
  bigdawg12
  Subscriber
- March 26, 2019 at 7:08 pm
  
  bigdawg12
  Subscriber
  
  I figured it out. The overflow error was caused from the time step in Setup. Setting the timescale factor to .01 rather than 1.0 sets the solution solver to start on a better set of numbers, thus it's more likely to converge on a solution.
- March 27, 2019 at 7:00 am
  
  Keyur Kanade
  Ansys Employee
  
  good that you figured it out.

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