1

Previous: PISO Up: Algorithms PISO and SIMPLE Next: simpleFOAM Solver General Properties

This is an automatically generated documentation by LaTeX2HTML utility. In case of any issue, please, contact us at info@cfdsupport.com.

SIMPLE

  • Assume Navier-Stokes equations for steady-state incompressible fluid flow
  • Mass conservation equation (continuity equation)

    134(11.8)

     

  • Momentum conservation equation (velocity equation)

    135(11.9)

     

  • When we discretize momentum conservation equation, we get:

    136(11.10)

     

  • Matrix linear system:

    137(11.11)

     

  • Matrix 121 is diagonal, with diagonal of original matrix 122
  • 123 is a vector corresponding to (crossref 3)
  • Rewriting (crossref 3) with substitution from (crossref 3):

    138(11.12)

     

  • Express 140 from equation (crossref 3), i.e. momentum correction equation :

    141(11.13)

     

  • To momentum correction equation (crossref 3) applying continuity equation (crossref 3) getting:

    142(11.14)

     

  • SIMPLE algorithm description:
  1. Computation starts, initial 128 and 129 are chosen
  2. Time step starts
  3. Boundary conditions are updated
  4. Linear system is solved 130
  5. Relaxation 128
  6. Obtained new 128
  7. Building matrix 121 and vector 123
  8. Mass flow over cell faces is computed
  9. Pressure correction is applied (crossref 3)
  10. Relaxation 129
  11. Obtained new 129
  12. Mass flow over cell faces is corrected
  13. Momentum correction is applied (crossref 3)
  14. Obtained new corrected 128
  15. Boundary conditions are updated
  16. Steps 5 – 15 are repeated with respect to nCorrectors value
  17. Time step ends

  • Source code of SIMPLE algorithm is implemented e.g. for solver simpleFoam:
    $FOAM_SOLVERS/incompressible/simpleFoam