Global Courant number

- October 15, 2021 at 12:02 pm
  
  i.tamunodienye2
  Subscriber
  
  Hello All,
  My global courant number is not falling below 1 (about 2.3 approx) even though sometimes the solution converges and other times it doesn't. I have so far reduced the time-step to 0.001 and increased the max iterations/Time-step to 40.
  Please i need help for what to do.
  
  Thanks
- October 15, 2021 at 2:55 pm
  
  RK
  Ansys Employee
  
  Hello,
  Please check your mesh as well. You might have to drop down the time step even further.
- October 15, 2021 at 4:03 pm
  
  i.tamunodienye2
  Subscriber
  
  Hello Do you mean i should increase my mesh size further?
- October 15, 2021 at 4:10 pm
  
  RK
  Ansys Employee
  
  Basically, C = del t / del x, where del x is the grid spacing. So, you can vary the time step or mesh accordingly. If the mesh is good, then you could reduce the time step further to achieve desired courant number
- October 15, 2021 at 4:30 pm
  
  i.tamunodienye2
  Subscriber
  
  I reduced the time step further to 0.0001. The Courant number reduced to approx 0.22 and the solution converged after 30 iterations.
  Is this good enough?