Computational Details:

"Leapfrogging of 2 smoke rings (same speed) at low Reynolds number"

• diameter of left/right semi-circle: 1.2/4.5
• diameter of hole in the wall : 0.2
• natural b.c.'s on semicircles with pressure drop=-1 for T in [0:4] and [10:14]; -0.1 else
• other b.c.'s: zero velocity at straight line ("wall") in interior
• initial condition at t=0: starting from rest
• viscosity parameter: 1/nu=100

• coarse mesh (=level 1): 198 cells, 222 vertices, 1,036 d.o.f.'s
  

  
  
  

• uniform refinements with exact boundary adaption
• visualization on level 4: 12,672 cells, 12,857 vertices, 63,728 d.o.f.`s
• computational mesh on level 5: 50,688 cells, 51,057 vertices, 254,176 d.o.f.`s
• nonconforming nonparametric rotated bilinear fem's (meanvalue version), UPW

• equidistant time stepping for computation with k=0.0066666667
• equidistant time stepping for visualization with k= 0.01 (= 1 frame)
• Total time T=50 seconds corresponds to 7,500 time steps
• fractional step theta scheme

• date: 04/07/98
• simulation by: S.Turek
• visualization by: S.Turek
• SUN ULTRA 45/250: 43 MB, 76,080 seconds
• AVS data: 1,895 MB
• Software: FEATFLOW1.0 + BOUSS

• For more details about numerical and algorithmic aspects see the `Mathematical Background' in the FEATFLOW manual or visit our paper archive for much more details.
• The problem-specific data for the applied software version including parameter files and input data can be downloaded here!