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Ron

如图左侧进口压力为0梯度，来流速度为抛物线分布，上下两边为0，中间最大。中点处速度从零开始平缓增大至最大值，其随时间的变化规律如下式，请问这种情况如何设置0文件夹下的边界条件呢？谢谢

Ron

计算圆管绕流，的流固耦合fsiFoam，库郎数和残差较大，第一个时间步长都计算不过去。使用了foam-extend3.1，迭代了30次都无法收敛，请教大神如何才能降低库郎数和残差让他收敛

Time = 0.00025, iteration: 30
Maximal accumulated displacement of interface points: 0.0030560221
GAMG:  Solving for cellMotionUx, Initial residual = 0.91131119, Final residual = 0.00072219997, No Iterations 1
GAMG:  Solving for cellMotionUy, Initial residual = 0.8372583, Final residual = 0.00018220686, No Iterations 4
GAMG:  Solving for cellMotionUz, Initial residual = 0.83907808, Final residual = 0.00074754473, No Iterations 3
GAMG:  Solving for cellMotionUx, Initial residual = 0.005840706, Final residual = 3.3755319e-06, No Iterations 5
GAMG:  Solving for cellMotionUy, Initial residual = 0.0014240355, Final residual = 9.3916646e-07, No Iterations 5
GAMG:  Solving for cellMotionUz, Initial residual = 0.0037156885, Final residual = 2.0135642e-06, No Iterations 5
Evolving flow model
Courant Number mean: 0.12920764 max: 2.1173853 velocity magnitude: 5.8284982
DILUPBiCG:  Solving for Ux, Initial residual = 0.00050711718, Final residual = 6.735853e-07, No Iterations 3
DILUPBiCG:  Solving for Uy, Initial residual = 0.00036428585, Final residual = 8.7737472e-07, No Iterations 3
DILUPBiCG:  Solving for Uz, Initial residual = 0.0016313381, Final residual = 1.5961465e-07, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.00108613, Final residual = 7.8685153e-07, No Iterations 8
GAMG:  Solving for p, Initial residual = 0.00019371718, Final residual = 5.401407e-07, No Iterations 5
time step continuity errors : sum local = 2.3989423e-09, global = -6.1017797e-11
GAMG:  Solving for p, Initial residual = 0.0003988323, Final residual = 4.1675183e-07, No Iterations 7
GAMG:  Solving for p, Initial residual = 4.9145888e-05, Final residual = 5.1093922e-07, No Iterations 4
time step continuity errors : sum local = 2.270261e-09, global = 2.9434889e-10
GAMG:  Solving for p, Initial residual = 8.1696621e-05, Final residual = 5.3236835e-07, No Iterations 5
GAMG:  Solving for p, Initial residual = 7.3969174e-06, Final residual = 4.311989e-07, No Iterations 2
time step continuity errors : sum local = 1.915783e-09, global = 2.5707342e-10
DILUPBiCG:  Solving for epsilon, Initial residual = 0.00031614333, Final residual = 1.050823e-07, No Iterations 3
DILUPBiCG:  Solving for k, Initial residual = 0.0012814958, Final residual = 4.2631276e-07, No Iterations 3
Setting traction on solid patch
Total force (fluid) = (-459.15346 -1.0986824 6.7686718e-06)
Total force (solid) = (459.1594 1.0991446 -6.379015e-06)

Time = 0.00025, iteration: 30
Maximal accumulated displacement of interface points: 0.065467478
GAMG:  Solving for cellMotionUx, Initial residual = 0.79783225, Final residual = 4.939853e-06, No Iterations 1
GAMG:  Solving for cellMotionUy, Initial residual = 0.98797867, Final residual = 0.00038088437, No Iterations 1
GAMG:  Solving for cellMotionUz, Initial residual = 0.99921705, Final residual = 0.00017911438, No Iterations 1
GAMG:  Solving for cellMotionUx, Initial residual = 1.2711546e-05, Final residual = 4.7196981e-07, No Iterations 3
GAMG:  Solving for cellMotionUy, Initial residual = 0.00037198031, Final residual = 6.6720231e-07, No Iterations 4
GAMG:  Solving for cellMotionUz, Initial residual = 0.00017081592, Final residual = 5.0439818e-07, No Iterations 4
Evolving flow model: consistentIcoFlow
Courant Number mean: 0.0090301047 max: 0.065159774 velocity magnitude: 0.057301147
DILUPBiCG:  Solving for Ux, Initial residual = 0.0026059227, Final residual = 7.4154757e-07, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.014165186, Final residual = 4.8137205e-09, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 0.008498764, Final residual = 2.0793996e-09, No Iterations 2
Consistent backwardDdtPhiCorr
GAMG:  Solving for p, Initial residual = 0.051049597, Final residual = 9.9704343e-07, No Iterations 126
GAMG:  Solving for p, Initial residual = 0.020685413, Final residual = 9.673727e-07, No Iterations 32
time step continuity errors : sum local = 3.1839476e-08, global = -2.5816328e-09
Consistent backwardDdtPhiCorr
GAMG:  Solving for p, Initial residual = 0.0063770573, Final residual = 9.5379753e-07, No Iterations 28
GAMG:  Solving for p, Initial residual = 0.0017021007, Final residual = 7.7514105e-07, No Iterations 7
time step continuity errors : sum local = 2.5870532e-08, global = -3.2020508e-09
Consistent backwardDdtPhiCorr
GAMG:  Solving for p, Initial residual = 0.00032173865, Final residual = 8.340539e-07, No Iterations 6
GAMG:  Solving for p, Initial residual = 6.000076e-05, Final residual = 9.9786163e-07, No Iterations 3
time step continuity errors : sum local = 3.324389e-08, global = 1.4105992e-09
Setting traction on solid patch
Total force (fluid2) = (-0.032864973 -7.3826261e-06 -8.2297438e-06)
Total force (solid) = (0.032882651 4.759419e-06 8.2338506e-06)
Evolving stress model
DICPCG: Solving for D, Initial residula = 9.4105628e-05, Final residual = 7.0815126e-05, No outer iterations = 62
Max relative residual = 0.00010949815, Relative residual = 9.6889967e-08, enforceLinear = 0
here. rheol
Current fsi relative residual norm: 0.99756477
there. rheo? 
ExecutionTime = 393.24 s  ClockTime = 393 s

forces output:
    forces(pressure, viscous)((459.60513 1.099789 -6.5750415e-06) (0.45167049 0.0011065994 1.9363028e-07))
    moment(pressure, viscous)((-0.27504867 114.90181 -0.00011651384) (-0.00027659408 0.11291678 -1.6157571e-05))

forceCoeffs output:
    Cd = 13.047032
    Cl = 0.031220971
    Cm = -7.5250194e-06

Time = 0.0005


Time = 0.0005, iteration: 1
Modes before clean-up : 28, modes after clean-up : 28
Maximal accumulated displacement of interface points: 131520.66
GAMG:  Solving for cellMotionUx, Initial residual = 0.99999997, Final residual = 0.00059804825, No Iterations 3
GAMG:  Solving for cellMotionUy, Initial residual = 1, Final residual = 0.00018112037, No Iterations 4
GAMG:  Solving for cellMotionUz, Initial residual = 1, Final residual = 0.00071242028, No Iterations 3
GAMG:  Solving for cellMotionUx, Initial residual = 0.00030676863, Final residual = 6.1484473e-07, No Iterations 4
GAMG:  Solving for cellMotionUy, Initial residual = 9.0611988e-05, Final residual = 9.4170358e-07, No Iterations 3
GAMG:  Solving for cellMotionUz, Initial residual = 0.00035888355, Final residual = 5.823629e-07, No Iterations 4
Evolving flow model
Courant Number mean: 4.4963525 max: 8386.7294 velocity magnitude: 223638.76
DILUPBiCG:  Solving for Ux, Initial residual = 0.99999848, Final residual = 1.0000271, No Iterations 1000
DILUPBiCG:  Solving for Uy, Initial residual = 0.99997733, Final residual = 0.99997733, No Iterations 1000
DILUPBiCG:  Solving for Uz, Initial residual = 0.99999992, Final residual = 0.99999992, No Iterations 1000
Floating point exception (core dumped)

* 列表
外侧流体 	epsilon 	k 	nut 	p 	pointmotion U 	U 	
INLET 	inletOutlet 	inletOutlet 	calculated 	zeroGradient 	fixedValue 	fixedValue 	
OUTLET 	inletOutlet 	inletOutlet 	calculated 	fixedValue 	fixedValue 	zeroGradient 	
FRONT_AND_BACK 	epsilonWallFunction 	kqRWallFunction 	nutkWallFunction 	zeroGradient 	fixedValue 	fixedValue 	
UP_AND_DOWN 	epsilonWallFunction 	kqRWallFunction 	nutkWallFunction 	zeroGradient 	fixedValue 	fixedValue 	
INTERFACE_INTERFACE 	epsilonWallFunction 	kqRWallFunction 	nutkWallFunction 	zeroGradient 	fixedValue 	movingWallVelocity 	
内侧流体 	epsilon 	k 	nut 	p 	pointmotion U 	U 	
INLET 	inletOutlet 	inletOutlet 	calculated 	zeroGradient 	fixedValue 	fixedValue 	
OUTLET 	inletOutlet 	inletOutlet 	calculated 	fixedValue 	zeroGradient 	zeroGradient 	
INTERFACEWATER 	epsilonWallFunction 	kqRWallFunction 	nutkWallFunction 	zeroGradient 	fixedValue 	movingWallVelocity 	
固体 	D 	pointD 	密度 	弹性模量 	泊松比 		
OUTERWALL 	tractionDisplacement 	calculated 	6500 	7.80E+10 	0.37 		
INNERWALL 	tractionDisplacement 	calculated 					
UP_AND_DOWN 	fixedValue 	fixedValue 		

控制条件为
application     fsiFoam.rheo;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         0.42;

deltaT          2.5e-4;

writeControl    runTime;

writeInterval   2.5e-3;

purgeWrite      0;

writeFormat     ascii;

writePrecision  8;

writeCompression uncompressed;

timeFormat      general;

timePrecision   6;

runTimeModifiable yes;

adjustTimeStep  yes;

maxCo           0.01;

maxdeltaT       2.5e-3;

fsi设置如下
solidPatch OUTERWALL;
solidZone OUTERWALL_zone;

fluidPatch INTERFACE_INTERFACE;
fluidZone INTERFACE_zone;

solidPatch2 INNERWALL;
solidZone2 INNERWALL_zone;

fluid2Patch INTERFACEWATER;
fluid2Zone INTERFACEWATER_zone;

relaxationFactor 0.01;

interfaceDeformationLimit 0;

outerCorrTolerance 1e-6;
nOuterCorr 20;

interpolatorUpdateFrequency 0;

//couplingScheme FixedRelaxation;
//couplingScheme Aitken;

couplingScheme IQN-ILS;
couplingReuse 1;

coupled yes;

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Ron

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