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- - **Study about a radiator**
(*https://www.cfd-online.com/Forums/openfoam-solving/102191-study-about-radiator.html*)

Study about a radiator3 Attachment(s)
Hi Foamers,
i'm working to study the behaviour of a radiator which it has 3 simple fingers. I use simpleFoam solver with realizableKE method for Newtonian fluid (water). I set up BCs in this way: INLET p --> zeroGradient U --> flowRateInletVelocity k --> initial value epsilon --> initial value nut --> calculated WALL p --> zeroGradient U --> fixedValue 0 k --> kqRWallFunction epsilon -->epsilonWallFunction nut --> 0 value OUTLET p --> 0 value U --> ? k --> ? epsilon --> ? nut --> calculated [Really, i've tried several method for the outlet, but i'm not sure about the right way ( inletOutlet, outletInlet, zeroGradient)]. Main goal is to find the velocity field and to reach the convergence in better way possible (time convergence, velocity's iteration, accuracy of solution). For now, nothing!! I don't know if i forget somethink or what. Why, when i've visualized in the paraview, does solution change for first time step, while not change for all rest (to each case that i tried)? I post my fingers and fvSolution, fvSchemes files. Regards!!! Vincenzo |

I would clarify one thing.. my first object is to understand which and why outlet's BCs must be used and the effects for each choosing. How I may set fvSchemes to have a corrected and consistent solution (for now, every solution is not correct).
After, i would discuss how the solution can be developed and improved. Thanks to all!! |

Hi all,
i'm trying to solve first problem of my case and i'm using inletOutlet for outlet's BCs in way to have zeroGradient. When simulation starts k converges rapidly and the other functions stay blocked. is It normal?? why don't the solution changes step by step? i show what happened: Time = 170 smoothSolver: Solving for Ux, Initial residual = 0.00055745698614, Final residual = 3.33918560038e-05, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 0.000123258066429, Final residual = 5.73185318398e-06, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.0023174939628, Final residual = 0.000141865924374, No Iterations 3 GAMG: Solving for p, Initial residual = 0.0162594175753, Final residual = 0.000702701530115, No Iterations 2 GAMG: Solving for p, Initial residual = 0.00418840145534, Final residual = 0.000153441787867, No Iterations 2 GAMG: Solving for p, Initial residual = 0.000983064579696, Final residual = 3.89487037296e-05, No Iterations 2 time step continuity errors : sum local = 0.00223007456523, global = -1.9700845204e-06, cumulative = 0.114629259665 smoothSolver: Solving for epsilon, Initial residual = 1.65537958175e-05, Final residual = 4.27652710707e-07, No Iterations 2 smoothSolver: Solving for k, Initial residual = 3.0933136533e-15, Final residual = 1.16840246856e-18, No Iterations 1 bounding k, min: 1.63989417126e-16 max: 3.65473424164 average: 0.0675839376248 ExecutionTime = 208.77 s ClockTime = 210 s ........ step by step ........ Time = 12000 smoothSolver: Solving for Ux, Initial residual = 0.000549283976902, Final residual = 3.23141590569e-05, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 0.000122228232637, Final residual = 5.56535850175e-06, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.0023001188588, Final residual = 0.000139948342846, No Iterations 3 GAMG: Solving for p, Initial residual = 0.0162353270075, Final residual = 0.000701558822586, No Iterations 2 GAMG: Solving for p, Initial residual = 0.00418917486882, Final residual = 0.000153149749499, No Iterations 2 GAMG: Solving for p, Initial residual = 0.000984176710849, Final residual = 3.88102094469e-05, No Iterations 2 time step continuity errors : sum local = 0.00222174367168, global = -3.00503702014e-06, cumulative = 0.113463870741 smoothSolver: Solving for epsilon, Initial residual = 1.61319652077e-05, Final residual = 4.02583277545e-07, No Iterations 2 smoothSolver: Solving for k, Initial residual = 3.0683752838e-15, Final residual = 1.04489246622e-18, No Iterations 1 bounding k, min: -8.45616718634e-10 max: 3.65502015206 average: 0.067576246466 ExecutionTime = 13908.82 s ClockTime = 13927 s Thanks to all!! |

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