- **OpenFOAM Running, Solving & CFD**
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- - **Iteration control **
(*https://www.cfd-online.com/Forums/openfoam-solving/59425-iteration-control.html*)

Is there a way to force solverIs there a way to force solvers to perform just ONE iteration at a time??
I am trying to work with a highly coupled system of equations and want to use the "solve" structures since they handle all the boundary conditions and can apply relaxation factors. I would have to set up my own kind of convergence control, but would be happy to get on with doing that if I could solve each equation one at a time. thanks. |

Come on people, this is criticCome on people, this is critical!!
I see that in the file lduMatrix.H, there is some code: 00206 //- Abstract base-class for lduMatrix solvers 00207 class solver 00208 { 00209 protected: 00210 00211 // Protected data 00212 00213 word fieldName_; 00214 const lduMatrix& matrix_; 00215 const FieldField<field,>& interfaceBouCoeffs_; 00216 const FieldField<field,>& interfaceIntCoeffs_; 00217 lduInterfaceFieldPtrsList interfaces_; 00218 00219 //- dictionary of controls 00220 dictionary controlDict_; 00221 00222 //- Maximum number of iterations in the solver 00223 label maxIter_; 00224 00225 //- Final convergence tolerance 00226 scalar tolerance_; 00227 00228 //- Convergence tolerance relative to the initial 00229 scalar relTol_; there is a label maxIter_ referred to. Does anyone know how/what/where to use this to chnage the maximum number of solver iterations from what seems to be 5001, to just 1. thanks. |

Okay Ken, you now have our attOkay Ken, you now have our attention.
I can't see where the '5001' is coming from either. The constructor in lduMatrix/lduMatrixSolver.C is using 1000. From your demand for help, I assume that the maxIter in the fvSolution isn't being respected? I guess this is critical - ie, a bug or a problem with your installation. eg, k smoothSolver { smoother GaussSeidel; nSweeps 2; tolerance 1e-7; relTol 0.1; maxIter 1; }; /mark |

thanks for the reply Mark.
thanks for the reply Mark.
I still can't figure out how to implement what you're suggesting. what I want, is to solve for variable phi_SR1 with solver ICCG to tol of 1e-6 relTol 0 (really tol and relTol are irrelevant for 1 iteration...) with iterMax = 1. your example showed: k smoothSolver { smoother GaussSeidel; nSweeps 2; tolerance 1e-7; relTol 0.1; maxIter 1; }; presumably this is in fvSolution? in your case, is k the variable to be solved? if I imitate with phi_SR1 solver or smoothSolver, I get an error. putting maxIter 1; anywhere seems to have no effect. how/where would you code what I'm trying to accomplish? thanks. |

Hi Ken,
Yes, you should be Hi Ken,
Yes, you should be adding your solver parameters into system/fvSolution. If you get an error with using phi_SRI smoothSolver { .... }; There is something else wrong (eg, you are not using a fv method, etc.). If this is not working properly, you can't place maxIter within the braces. After you get this sorted out, you might even try just using relTol=1 (or 0.999). I would think that this should give a similar result as limiting the maxIter explicitly. |

Ok thanks!
it's working as Ok thanks!
it's working as required, one hitch was that I am using subdomains and in our recently implemented v1.4, it wasn't obvious that additional fvSolution files are now required subdomain system directories... blood pressure now returning to normal level.... |

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