|
[Sponsors] |
negative initial temperature/ exceeded number of max. iteratons |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
July 12, 2020, 13:37 |
negative initial temperature/ exceeded number of max. iteratons
|
#1 |
New Member
Join Date: Jan 2020
Posts: 26
Rep Power: 6 |
Hey,
I try to calculate heat transfer between a fluid in a pipe (water) and the encircling pipe and soil, using OF6 and the chtMultiRegionFoam solver for a steady state calculation. The model crashes with the fatal error of exceede Maximum number of iterations as well the Courant-number drops below 0, what I consider as part of the problem. Code:
Region: fluid Courant Number mean: -0.0910146934732 max: -0.00351789034512 Region: pipewall Diffusion Number mean: 2.67864717358e-06 max: 0.000233164935363 Region: soil_1 Diffusion Number mean: 5.82937716003e-06 max: 7.56997601431e-05 deltaT = 4.68264248705 Time = 10 Solving for fluid region fluid DILUPBiCGStab: Solving for Ux, Initial residual = 0.929863015554, Final residual = 1.9550289574, No Iterations 1000 DILUPBiCGStab: Solving for Uy, Initial residual = 0.978339899353, Final residual = 1.05520532405, No Iterations 1000 DILUPBiCGStab: Solving for Uz, Initial residual = 0.999766111841, Final residual = 8.79009066096e-05, No Iterations 1000 DILUPBiCGStab: Solving for e, Initial residual = 1, Final residual = 1386552.30948, No Iterations 1000 --> FOAM FATAL ERROR: Maximum number of iterations exceeded: 100 I read in the forum to check the mesh but I could not find any error. If I try the same model with Euler instead of steady state, it crashes with a negative initial temperature and a extrem high courant-number (I fixed maxCo to 1 in controlDict, but it seems to be ignored). Code:
Region: fluid Courant Number mean: 28.0700323842 max: 3023.8583768 Region: pipewall Diffusion Number mean: 9.88492992534e-05 max: 0.00860441445906 Region: soil_1 Diffusion Number mean: 2.15119726494e-05 max: 0.000279352514867 deltaT = 5.92803286081e-06 Time = 388.886 Solving for fluid region fluid diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 DILUPBiCGStab: Solving for Ux, Initial residual = 0.0861844749054, Final residual = 3.10312044775e-07, No Iterations 2 DILUPBiCGStab: Solving for Uy, Initial residual = 0.215185941109, Final residual = 1.92800159784e-07, No Iterations 2 DILUPBiCGStab: Solving for Uz, Initial residual = 0.0288023464831, Final residual = 1.83257387023e-08, No Iterations 2 DILUPBiCGStab: Solving for e, Initial residual = 0.256558566591, Final residual = 8.40025755292e-07, No Iterations 2 --> FOAM FATAL ERROR: Negative initial temperature T0: -845.998590083 Given that my model had none of those problems in OF7, I believe that the boundary conditions should be fine, so I dont know how to fix this issue. Do you have some hint how to solve it? |
|
Tags |
chtmultiregionfoam, courant number, iterations exceeded, negative initial temp |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
y+ and u+ values with low-Re RANS turbulence models: utility + testcase | florian_krause | OpenFOAM | 114 | August 23, 2023 06:37 |
Converging Diverging Nozzle with dbnsTurbFoam | Saleh Abuhanieh | OpenFOAM Running, Solving & CFD | 4 | December 13, 2019 11:26 |
Segmentation fault when using reactingFOAM for Fluids | Tommy Floessner | OpenFOAM Running, Solving & CFD | 4 | April 22, 2018 13:30 |
SigFpe when running ANY application in parallel | Pj. | OpenFOAM Running, Solving & CFD | 3 | April 23, 2015 15:53 |
Moving mesh | Niklas Wikstrom (Wikstrom) | OpenFOAM Running, Solving & CFD | 122 | June 15, 2014 07:20 |