Significance of pseudo time step in Ansys Fluent

- March 28, 2020 at 7:07 am
  
  cfd_learner
  Subscriber
  
  Hi,
  
  What is the significance/understanding of the pseudo auto time step in Ansys Fluent?
  
  For Ex: 0.1, 1.0, 10 what will happen with these time scale factors in context to accuracy and convergence?
  
  Regards.
- March 28, 2020 at 8:43 am
  
  vinayak chauhan
  Subscriber
  
  Hi,
  
  pseudo time-stepping also known as pseudo-transient continuation, is the technique of solving the steady-state solution of time-evolving partial differential equations by setting an initial guess(t') and using a time-stepper to evolve the solution forward.
  
  using this t' we get a new value and then setting it as an initial value we do the same calculation.
- March 28, 2020 at 9:00 am
  
  cfd_learner
  Subscriber
  
  what is its effect on the accuracy if either use a time scale factor of 0.1, 1.0 or 10?
- March 28, 2020 at 9:31 am
  
  vinayak chauhan
  Subscriber
  
  hi,
  
  When you reduce the size of element, you are recommended to reduce the time step correspondingly. Hence you need to scale it down or up based on your mesh details for better results. Also time steps judge the number of iterations for convergence.