Back to Start Page Introduction Motivation Contents Current State Outlook New Videos Featflow Home Page Contact



Computational Details:

"Flow through a Venturi pipe at medium up to high Reynolds number" Back to >>Flow through a Venturi pipe at medium up to high Reynolds number<<


Description of the flow problem
Description of the spatial discretization on grid `a'
Description of the spatial discretization on grid `b'
Description of the temporal discretization
Computer requirements
Mathematical details




Description of the flow problem

  • length of channel: 72.6, maximum height 7.8, minimum diameter of pipe 1, width of upper small device 0.8
  • inflow b.c.'s: constant velocity 1 at the left edge
  • outflow b.c.'s: natural "do nothing" b.c.'s at right edge and upper small device
  • other b.c.'s: zero velocity at fixed walls
  • initial condition at t=0: starting from Stokes solution
  • viscosity parameter: 1/nu=1000 (maximum velocity about 7!)




Description of the spatial discretization on grid `a'

  • coarse mesh (=level 1): 12 cells, 26 vertices, 86 d.o.f.`s



  • uniform refinements with exact boundary adaption
  • visualization on level 6: 12,288 cells, 12,705 vertices, 62,272 d.o.f.`s
  • level 7: 49,152 cells, 49,985 vertices, 247,424 d.o.f.`s
  • level 8: 196,608 cells, 198,273 vertices, 986,368 d.o.f.`s
  • maximum mesh on level 9: 786,432 cells, 789,761 vertices, 3,938,816 d.o.f.`s
  • nonconforming nonparametric rotated bilinear fem's (meanvalue version), Samarskij upwinding




Description of the spatial discretization on grid `b'

  • coarse mesh (=level 1): 22 cells, 37 vertices, 138 d.o.f.`s



  • uniform refinements with exact boundary adaption
  • visualization on level 5: 5,632 cells, 5,857 vertices, 28,608 d.o.f.`s
  • level 6: 22,528 cells, 22,977 vertices, 113,536 d.o.f.`s
  • level 7: 90,112 cells, 91,009 vertices, 452,352 d.o.f.`s
  • maximum mesh on level 8: 360,448 cells, 362,241 vertices, 1,805,824 d.o.f.`s
  • nonconforming nonparametric rotated bilinear fem's (meanvalue version), Samarskij upwinding




Description of the temporal discretization

  • adaptive time stepping with control of velocity
  • Total time T=30
  • fractional step theta scheme




Computer requirements

  • date: 02/25/98
  • simulation by: S.Turek
  • visualization by: S.Turek
  • Software: FEATFLOW1.0 + BOUSS




Mathematical details

  • 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! Additionally, you may download the gnuplot files for the drag and lift plots here, or the complete output protocol files here!
  • A set of AVS data for a complete movie (calculated on level 8) can be downloaded here !




Please send any comments and suggestions to: featflow@featflow.de