Run Calculation (Time Steps, Number of Steps)

- March 1, 2021 at 4:11 pm
  
  michutorres
  Subscriber
  
  Hi all,nMy work consists on a heating and melting of an adhesive and I need to simulate it in Ansys Fluent for about 30 minutes.nIn Run Calculation, if I want to simulate 30 minutes, which values for Time Steps, Number of Steps and Max Iterations/Time Step you recommend? Actually I am not understanding what they mean.nThank you for your help.nn
- March 1, 2021 at 4:44 pm
  
  Rob
  Forum Moderator
  
  Time step is the time increment Fluent uses to update the transient solution. Number of steps is how many of those you want to run. Max iterations is how many iterations Fluent can run in each time step. The first two are for you to calculate. The latter needs to be enough such that the solver converges in the time step, ideally in about 10-15 iterations. n
- July 30, 2023 at 5:06 pm
  
  ajain707
  Subscriber
  
  Hi
  I am confused about setting these numbers up as well. I want to see steady state response for 30 minutes of fluid flow through a cold plate. How can i calculate number of iterations, reporting interval, and profile update interval ?
- July 31, 2023 at 8:08 am
  
  SRP
  Ansys Employee
  
  Hi,
  In steady-state simulations, the solver iterates until the solution converges, meaning the solution reaches a stable state where the residuals of the governing equations become small enough. The number of iterations required to reach convergence can vary depending on the complexity of the problem, the mesh size, and the solver settings. To determine the number of iterations, you can set a maximum limit and let the simulation run. Monitor the residual plots during the simulation. If the residuals level off and reach a plateau well before the maximum limit, the simulation has likely converged.
  Thank you.