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Iteration Output

  • What are those iteration records?
  • Lat us take a closer look at e.g. time 0.49 s:
    Time = 0.49
    

  • Time means physical time in seconds
    Courant Number mean: 0.222158 max: 0.852134
    

  • Courant Number mean/max is mean/maximal CFL number for convergence condition:
    25(8.2)

     

     

    DILUPBiCG:  Solving for Ux, Initial residual = 2.09588e-07, Final residual = 2.09588e-07, No Iterations 0
    

  • DILUPBiCG is linear system solver for U (Diagonal Incomplete LU Decomposition Preconditioned Bi-Conjugate Gradient)
  • Linear system solver set-up is in file fvSolution
  • Solver decomposes velocity vector into components and solves them separately
  • Initial residual is the measure of stability of solution with respect to previous iteration.
  • Final residual is the residual when linear system solver has finished.
  • No Iterations is number of iterations of linear system solver
    DICPCG:  Solving for p, Initial residual = 1.0746e-06, Final residual = 3.53797e-07, No Iterations 1
    

  • DICPCG is linear system solver used for pressure (Diagonal Incomplete Cholesky Preconditioned Conjugate Gradient)
  • In PISO algorithm the pressure computation is repeated according to number of correctors nCorrectors
    time step continuity errors : sum local = 9.1113e-09, global = -6.21295e-19, cumulative = 1.23378e-18
    

  • time step continuity errors represent certain measures of continuity equation violation
    ExecutionTime = 0.27 s  ClockTime = 0 s
    

  • ExecutionTime is the time elapsed since the start of the computation
  • ClockTime is the time spent on processor(s)