OpenFOAM中LES输出最终残差问题

coolhhh

LES模拟，调用了residuals函数输出残差，但发现输出的结果是每步计算的初始残差。根据函数的描述也是输出 initial residuals。请问大家有什么方法可以输出final residuals吗？

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
-------------------------------------------------------------------------------
Description
    For specified fields, writes out the initial residuals for the first
    solution of each time step; for non-scalar fields (e.g. vectors), writes
    the largest of the residuals for each component (e.g. x, y, z).

\*---------------------------------------------------------------------------*/

#includeEtc "caseDicts/postProcessing/numerical/residuals.cfg"

fields (p U);

// ************************************************************************* //

bestucan

https://www.cfd-online.com/Forums/openfoam-solving/181927-buoyantsimplefoam-not-plotting-residuals.html#post632303

是因为没开预测么？

李东岳

我更关注的是，为什么你不关注initial residual，而是关注final residual

coolhhh

@bestucan

好像不是这个问题，下面是我输出的 log.pisoFoam 和对应的 residuals.dat。 residuals.dat 输出的都是每步计算开始的 Initial residual，好像无法选择输出每步计算最后的 Final residual
计算的log.pisoFoam文件

Time = 0.0015

Courant Number mean: 0.18933236 max: 3.0134083
smoothSolver:  Solving for Ux, Initial residual = 0.94279208, Final residual = 4.1036105e-07, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 0.24479151, Final residual = 9.6080469e-07, No Iterations 3
smoothSolver:  Solving for Uz, Initial residual = 0.21776409, Final residual = 8.4350179e-07, No Iterations 3
GAMG:  Solving for p, Initial residual = 0.0048258603, Final residual = 0.00021860641, No Iterations 18
GAMG:  Solving for p, Initial residual = 0.17069422, Final residual = 0.0063724156, No Iterations 2
time step continuity errors : sum local = 5.5286369e-05, global = 2.8590342e-06, cumulative = 2.6884486e-05
GAMG:  Solving for p, Initial residual = 0.025078242, Final residual = 0.0012531841, No Iterations 16
GAMG:  Solving for p, Initial residual = 0.058320856, Final residual = 0.0028998385, No Iterations 27
time step continuity errors : sum local = 2.6808848e-06, global = -4.4628639e-09, cumulative = 2.6880023e-05
GAMG:  Solving for p, Initial residual = 0.017046775, Final residual = 0.0008362502, No Iterations 36
GAMG:  Solving for p, Initial residual = 0.0020386497, Final residual = 9.9487967e-07, No Iterations 305
time step continuity errors : sum local = 8.7201563e-10, global = -1.7811338e-12, cumulative = 2.6880021e-05
ExecutionTime = 16.02 s  ClockTime = 16 s

对应输出的 residuals.dat 文件

# Residuals     
# Time          	p               	Ux              	Uy              	Uz              
0               	N/A	N/A
0.0005          	1.00000000e+00	1.00000000e+00	1.00000000e+00	1.00000000e+00
0.001           	3.79477181e-03	9.31777378e-01	3.20163786e-01	3.21921547e-01
0.0015          	4.82586027e-03	9.42792079e-01	2.44791510e-01	2.17764088e-01

coolhhh

@李东岳
李老师，我本来是想输出最终残差后，画个最终残差曲线看下每步计算最后的收敛情况。我是加载入口脉动风计算，初始残差每步都是会比较大，所以比较关注每步计算的最终残差效果。

bestucan

@coolhhh
终端切换到 log.pisoFoam 所在的文件夹，运行这句

grep 'Final residual' log.pisoFoam | awk -F ',' '{print $3}' | cut -d "=" -f2 > finRes.log

coolhhh

@bestucan 完美解决，谢谢大佬

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OpenFOAM中LES输出最终残差问题