动网格和overset物体速度快速震荡导致崩溃的问题



  • 各位老哥
    最近在做一个波浪中物体二自由度的运动案例,最开始使用普通的动网格来计算的,因为计算幅度可以接受,但是结果却发现在开始计算0.2s左右,计算就发散了,发散的原因是物体Z方向上的速度急剧增大,之前遇到这类问题,都是因为运动幅度过大导致网格扭曲出现的,但是当前才0.2s 物体的运动幅度可以忽略,从网格也看不出来有什么扭曲。 然后我就把案例改成了overset的案例,结果还是类似的出错结果,速度急剧增大,而且物体的Z方向受力来回震荡,并且震荡的幅度特别大,正常浮力和重力就是140 左右 就算全部浸没也不过超过200 但是从log文件经常会一个时间步就几千受力变化。
    而且非常奇怪的是,动网格案例在保证浮力重力平衡的情况下增大了物体的吃水,就可以运行了,同样的修改Overset还是不能运行,虽然动网格上述修改虽然可以运行,但是不是想要的结果,所以请教一下各位,是否有人之前遇到过相似的问题,这里万般感谢:xinxin:
    最后分别附上两个案例两到三个时间步的log文件计算结果,可以看这几个时间步Z方向的force变化

    动网格案例 连续两个时间步 Z方向受力 分别是 252和1572 之后就越来越大,最终冲破天际了

    deltaT = 0.00101181857516
    Time = 0.220738
    
    PIMPLE: iteration 1
    forces forces:
        Not including porosity effects
    
    Rigid-body motion of the floatingObject
        Centre of rotation: (0 0 0.00108368499676)
        Orientation: (1 0 3.3789845961e-07 0 1 0 -3.3789845961e-07 0 1)
        Linear velocity: (0 0 0.0612626535315)
        Angular velocity: (0 3.62258814109e-05 0)
    Execution time for mesh.update() = 0.5 s
    smoothSolver:  Solving for alpha.water, Initial residual = 8.23816903596e-06, Final residual = 7.16032233336e-10, No Iterations 1
    Phase-1 volume fraction = 0.500312200358  Min(alpha.water) = -6.36232220187e-30  Max(alpha.water) = 1.00866542511
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.500312200358  Min(alpha.water) = -6.3458477003e-30  Max(alpha.water) = 1.00866542511
    Relaxing time: 0.01 s
    GAMG:  Solving for p_rgh, Initial residual = 8.64298692691e-05, Final residual = 9.8169399241e-06, No Iterations 9
    GAMG:  Solving for p_rgh, Initial residual = 0.00010348168853, Final residual = 9.24900730207e-06, No Iterations 7
    time step continuity errors : sum local = 6.61490084731e-08, global = -7.14845366174e-10, cumulative = 2.01813122868e-07
    GAMG:  Solving for p_rgh, Initial residual = 1.16441732373e-05, Final residual = 3.42047154349e-06, No Iterations 1
    GAMG:  Solving for p_rgh, Initial residual = 3.4197011599e-06, Final residual = 3.4197011599e-06, No Iterations 0
    time step continuity errors : sum local = 2.69615713834e-08, global = -9.20554877097e-10, cumulative = 2.00892567991e-07
    ExecutionTime = 51.32 s  ClockTime = 51 s
    
    forces forces1 write:
        Sum of forces
            Total    : (-0.18127711571 -1.88236463748e-23 252.403179473)
            Pressure : (-0.18127697457 -1.88237660153e-23 252.415146697)
            Viscous  : (-1.41140473911e-07 1.19640498385e-28 -0.0119672240877)
        Sum of moments
            Total    : (-1.90023955902e-24 -0.0845601499345 3.06605212083e-26)
            Pressure : (-1.90025359991e-24 -0.0845600163142 3.06618198123e-26)
            Viscous  : (1.40408941158e-29 -1.33620321663e-07 -1.29860396598e-30)
    
    
    Courant Number mean: 0.00254798035261 max: 0.18775947338
    Interface Courant Number mean: 2.3084939728e-05 max: 0.0564074055803
    deltaT = 0.00107823137739
    Time = 0.221816
    
    PIMPLE: iteration 1
    forces forces:
        Not including porosity effects
    
    Rigid-body motion of the floatingObject
        Centre of rotation: (0 0 0.00113322650212)
        Orientation: (1 0 3.68934121974e-07 0 1 0 -3.68934121974e-07 0 1)
        Linear velocity: (0 0 0.0306313617895)
        Angular velocity: (0 -9.37936039134e-05 0)
    Execution time for mesh.update() = 0.5 s
    smoothSolver:  Solving for alpha.water, Initial residual = 1.12888430008e-05, Final residual = 8.47616724924e-10, No Iterations 1
    Phase-1 volume fraction = 0.500310401852  Min(alpha.water) = -6.30568122573e-30  Max(alpha.water) = 1.00798849325
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.500310401852  Min(alpha.water) = -6.28823415663e-30  Max(alpha.water) = 1.00798849325
    Relaxing time: 0.01 s
    GAMG:  Solving for p_rgh, Initial residual = 0.000826027305677, Final residual = 9.345892666e-06, No Iterations 19
    GAMG:  Solving for p_rgh, Initial residual = 7.55055385995e-07, Final residual = 7.55055385995e-07, No Iterations 0
    time step continuity errors : sum local = 9.73939319788e-08, global = -8.90956534845e-10, cumulative = 2.00001611456e-07
    GAMG:  Solving for p_rgh, Initial residual = 2.61538748518e-06, Final residual = 2.61538748518e-06, No Iterations 0
    GAMG:  Solving for p_rgh, Initial residual = 2.61538748518e-06, Final residual = 2.61538748518e-06, No Iterations 0
    time step continuity errors : sum local = 3.3735638182e-07, global = -1.86581070005e-09, cumulative = 1.98135800756e-07
    ExecutionTime = 52.1 s  ClockTime = 52 s
    
    forces forces1 write:
        Sum of forces
            Total    : (0.000986698924306 2.13856484196e-23 1572.88591645)
            Pressure : (0.000986998775467 2.13856973379e-23 1572.89201928)
            Viscous  : (-2.99851160528e-07 -4.89182974308e-29 -0.00610283104064)
        Sum of moments
            Total    : (2.22842317366e-24 0.0084773625331 8.87541932908e-25)
            Pressure : (2.22842813704e-24 0.00847733423395 8.87542806285e-25)
            Viscous  : (-4.96338833053e-30 2.82991556891e-08 -8.73376717721e-31)
    
    

    overset案例 这几个连续的时间步,Z方向的受力分别是 146 -636 531 1219 最后也是越来越大

    deltaT = 0.00243433879711
    Time = 0.216152
    
    PIMPLE: iteration 1
    motion_.dropFlag: 0     
     时间 db().time().value():0.216152429581在算了
    forces forces:
        rho: rho
        Not including porosity effects
    
    6-DoF rigid body motion
        Centre of rotation: (0 0 -0.0213300442367)
        Centre of mass: (8.76359257368e-09 0 -0.00093004423675)
        Orientation: (1 0 4.29587871259e-07 0 1 0 -4.29587871259e-07 0 1)
        Linear velocity: (0 0 -0.031497857265)
        Angular velocity: (-0 -1.27419889364e-05 0)
    cellVolumeWeight : detected 2 mesh regions
    
        zone:0 nCells:400000
        zone:1 nCells:17900
    Marking patch-cells on zone 0
    Marking patch-cells on zone 1
    
    After patch analysis : nCells : 417900
        other  : 412560
        patch  : 4744
        overset: 596
    
    Creating mesh-to-mesh addressing for region0 and region0 regions using cellVolumeWeight
    meshToMesh: Using AABBTree method
        Overlap volume: 0.134053289585
    cellVolumeWeight : detected 6 mesh regions after overset
    
    Front : fraction:1 size:1160
    Overset analysis : nCells : 417900
        calculated   : 411602
        interpolated : 946
        hole         : 5352
    
    Updating StokesII wave model for patch inlet
    Updating shallowWaterAbsorption wave model for patch outlet
    Execution time for mesh.update() = 5.19 s
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.75648006434e-06, Final residual = 3.47092057926e-11, No Iterations 2
    Phase-1 volume fraction = 0.405001375012  Min(alpha.water) = -6.44107925227e-19  Max(alpha.water) = 1.00018322668
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405001377548  Min(alpha.water) = -1.52464097061e-17  Max(alpha.water) = 1.00018322668
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.75808827335e-06, Final residual = 3.46761931325e-11, No Iterations 2
    Phase-1 volume fraction = 0.405008116411  Min(alpha.water) = -4.2632907881e-19  Max(alpha.water) = 1.0001801161
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405008119026  Min(alpha.water) = -1.47698402771e-17  Max(alpha.water) = 1.0001801161
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 7.73918900558e-05, Final residual = 7.70896010266e-07, No Iterations 179
    time step continuity errors : sum local = 1.39938130275e-07, global = 6.49571398554e-08, cumulative = 4.25418012787e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 0.000258484674878, Final residual = 8.84289053292e-10, No Iterations 402
    time step continuity errors : sum local = 3.55495897207e-12, global = -1.37045513846e-12, cumulative = 4.25417875741e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.00248482816424, Final residual = 6.85528578613e-09, No Iterations 15
    smoothSolver:  Solving for k, Initial residual = 0.031742998684, Final residual = 9.07836013528e-09, No Iterations 29
    PIMPLE: iteration 2
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 9.70110690882e-06, Final residual = 3.98515135285e-11, No Iterations 2
    Phase-1 volume fraction = 0.405001348864  Min(alpha.water) = -1.03030772084e-18  Max(alpha.water) = 1.00018324609
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405001351346  Min(alpha.water) = -1.36436906282e-17  Max(alpha.water) = 1.00018324609
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.73423582573e-06, Final residual = 3.1136314758e-11, No Iterations 2
    Phase-1 volume fraction = 0.405008063893  Min(alpha.water) = -4.26329047505e-19  Max(alpha.water) = 1.00018015426
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405008066489  Min(alpha.water) = -1.30693638106e-17  Max(alpha.water) = 1.00018015426
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 0.000118616893935, Final residual = 9.3012114721e-07, No Iterations 152
    time step continuity errors : sum local = 3.13276633314e-09, global = 2.56566848953e-12, cumulative = 4.25418132308e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 0.00011827675578, Final residual = 9.41783544077e-10, No Iterations 305
    time step continuity errors : sum local = 5.45493528694e-13, global = -5.65974338958e-14, cumulative = 4.25418126648e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.000163531317999, Final residual = 7.97099529407e-09, No Iterations 8
    smoothSolver:  Solving for k, Initial residual = 0.00062846546524, Final residual = 7.07149761854e-09, No Iterations 21
    ExecutionTime = 179.75 s  ClockTime = 185 s
    
    forces forces1 write:
        Sum of forces
            Total    : (-0.000835011808457 -5.45382368796e-24 146.54637577)
            Pressure : (-0.000835029384371 -5.45374863573e-24 146.526422965)
            Viscous  : (1.75759144188e-08 -7.50522339763e-29 0.019952805856)
        Sum of moments
            Total    : (-5.21201731689e-25 0.00027807004677 -4.71054295058e-26)
            Pressure : (-5.21194290964e-25 0.00027789856482 -4.71023222581e-26)
            Viscous  : (-7.44072488661e-30 1.71481949812e-07 -3.10724768134e-30)
    
    
    Courant Number mean: 0.00312599378064 max: 0.293259735409
    Interface Courant Number mean: 2.05386331858e-05 max: 0.114626092226
    deltaT = 0.00249028949752
    Time = 0.218643
    
    PIMPLE: iteration 1
    motion_.dropFlag: 0     
     时间 db().time().value():0.218642711639在算了
    forces forces:
        rho: rho
        Not including porosity effects
    
    6-DoF rigid body motion
        Centre of rotation: (0 0 -0.0213682344606)
        Centre of mass: (8.20449051472e-09 0 -0.000968234460565)
        Orientation: (1 0 4.02180907584e-07 0 1 0 -4.02180907584e-07 0 1)
        Linear velocity: (0 0 0.000826544670072)
        Angular velocity: (-0 -9.26907740871e-06 0)
    cellVolumeWeight : detected 2 mesh regions
    
        zone:0 nCells:400000
        zone:1 nCells:17900
    Marking patch-cells on zone 0
    Marking patch-cells on zone 1
    
    After patch analysis : nCells : 417900
        other  : 412560
        patch  : 4744
        overset: 596
    
    Creating mesh-to-mesh addressing for region0 and region0 regions using cellVolumeWeight
    meshToMesh: Using AABBTree method
        Overlap volume: 0.134045212245
    cellVolumeWeight : detected 6 mesh regions after overset
    
    Front : fraction:1 size:1162
    Overset analysis : nCells : 417900
        calculated   : 411600
        interpolated : 946
        hole         : 5354
    
    Updating StokesII wave model for patch inlet
    Updating shallowWaterAbsorption wave model for patch outlet
    Execution time for mesh.update() = 5.42 s
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.09338592432e-06, Final residual = 2.40627946583e-11, No Iterations 2
    Phase-1 volume fraction = 0.405014125102  Min(alpha.water) = -4.26328384992e-19  Max(alpha.water) = 1.00017701078
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405014127847  Min(alpha.water) = -1.04461042326e-17  Max(alpha.water) = 1.00017701078
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.09441137905e-06, Final residual = 2.40259634767e-11, No Iterations 2
    Phase-1 volume fraction = 0.405020187051  Min(alpha.water) = -4.26327722332e-19  Max(alpha.water) = 1.00017392216
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405020189807  Min(alpha.water) = -9.5120499276e-18  Max(alpha.water) = 1.00017392216
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 0.0574319353605, Final residual = 0.000481714923153, No Iterations 252
    time step continuity errors : sum local = 1.52454599301e-07, global = 4.71011922379e-08, cumulative = 4.30128245872e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.25353035601e-05, Final residual = 5.41520666851e-10, No Iterations 308
    time step continuity errors : sum local = 6.27030222368e-10, global = 2.53603809451e-10, cumulative = 4.30153606253e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.0012437548912, Final residual = 7.78688153486e-09, No Iterations 15
    smoothSolver:  Solving for k, Initial residual = 0.0115461348311, Final residual = 6.65057162803e-09, No Iterations 30
    PIMPLE: iteration 2
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 1.02524778268e-05, Final residual = 1.47321270306e-11, No Iterations 2
    Phase-1 volume fraction = 0.405011011353  Min(alpha.water) = -4.25540370391e-19  Max(alpha.water) = 1.00017702627
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405011013529  Min(alpha.water) = -9.64123997826e-18  Max(alpha.water) = 1.00017702627
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 2.9666532562e-06, Final residual = 4.89153378505e-12, No Iterations 2
    Phase-1 volume fraction = 0.405013958567  Min(alpha.water) = -4.24733396239e-19  Max(alpha.water) = 1.0001739526
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405013960729  Min(alpha.water) = -8.74233411734e-18  Max(alpha.water) = 1.0001739526
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.52984166079e-05, Final residual = 1.1946067314e-07, No Iterations 165
    time step continuity errors : sum local = 5.571216882e-08, global = -2.13063622342e-08, cumulative = 4.2802297003e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 3.63683899449e-06, Final residual = 9.07496366273e-10, No Iterations 265
    time step continuity errors : sum local = 3.97777309263e-10, global = -1.12705790442e-11, cumulative = 4.28021842972e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.000332863393295, Final residual = 9.72253472451e-09, No Iterations 8
    smoothSolver:  Solving for k, Initial residual = 0.00373997689702, Final residual = 7.30870966919e-09, No Iterations 22
    ExecutionTime = 186.5 s  ClockTime = 192 s
    
    forces forces1 write:
        Sum of forces
            Total    : (-0.000928906233233 -1.80429377211e-23 -636.496207569)
            Pressure : (-0.00092895466669 -1.8042996157e-23 -636.505199892)
            Viscous  : (4.84334573672e-08 5.84358832828e-29 0.00899232345785)
        Sum of moments
            Total    : (-1.87852470623e-24 -0.000321059082781 5.79075401727e-25)
            Pressure : (-1.87853074491e-24 -0.000321189856886 5.79065804127e-25)
            Viscous  : (6.03867806002e-30 1.30774104865e-07 9.5975999502e-30)
    
    
    Courant Number mean: 0.00142003472523 max: 0.161714928462
    Interface Courant Number mean: 1.28565593805e-05 max: 0.0762584687927
    deltaT = 0.00295226716177
    Time = 0.221595
    
    PIMPLE: iteration 1
    motion_.dropFlag: 0     
     时间 db().time().value():0.2215949893在算了
    forces forces:
        rho: rho
        Not including porosity effects
    
    6-DoF rigid body motion
        Centre of rotation: (0 0 -0.0214711935557)
        Centre of mass: (7.64296276984e-09 0 -0.00107119355569)
        Orientation: (1 0 3.74655037737e-07 0 1 0 -3.74655037737e-07 0 1)
        Linear velocity: (-0 -0 -0.0705757167347)
        Angular velocity: (0 -9.37819828747e-06 0)
    cellVolumeWeight : detected 2 mesh regions
    
        zone:0 nCells:400000
        zone:1 nCells:17900
    Marking patch-cells on zone 0
    Marking patch-cells on zone 1
    
    After patch analysis : nCells : 417900
        other  : 412560
        patch  : 4744
        overset: 596
    
    Creating mesh-to-mesh addressing for region0 and region0 regions using cellVolumeWeight
    meshToMesh: Using AABBTree method
        Overlap volume: 0.134023436314
    cellVolumeWeight : detected 6 mesh regions after overset
    
    Front : fraction:1 size:1160
    Overset analysis : nCells : 417900
        calculated   : 411603
        interpolated : 946
        hole         : 5351
    
    Updating StokesII wave model for patch inlet
    Updating shallowWaterAbsorption wave model for patch outlet
    Execution time for mesh.update() = 5.42 s
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 4.42900348917e-06, Final residual = 2.17379099773e-11, No Iterations 2
    Phase-1 volume fraction = 0.405018146117  Min(alpha.water) = -4.24712034214e-19  Max(alpha.water) = 1.0001703247
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405018148869  Min(alpha.water) = -9.29879584239e-18  Max(alpha.water) = 1.0001703247
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 4.42989278502e-06, Final residual = 2.17934542479e-11, No Iterations 2
    Phase-1 volume fraction = 0.405022334772  Min(alpha.water) = -4.24690670976e-19  Max(alpha.water) = 1.00016677246
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405022337485  Min(alpha.water) = -9.04251837334e-18  Max(alpha.water) = 1.00016677246
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 8.54275986038e-05, Final residual = 8.53589063447e-07, No Iterations 225
    time step continuity errors : sum local = 3.90972219194e-07, global = -3.45881020884e-08, cumulative = 4.24563032763e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.43373913745e-05, Final residual = 8.92239560876e-10, No Iterations 309
    time step continuity errors : sum local = 6.45604355038e-10, global = -2.89604346639e-10, cumulative = 4.24534072328e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.00275285932027, Final residual = 6.75345368991e-09, No Iterations 18
    smoothSolver:  Solving for k, Initial residual = 0.0263178579155, Final residual = 7.36925710592e-09, No Iterations 35
    PIMPLE: iteration 2
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.72099553241e-06, Final residual = 3.18138525737e-11, No Iterations 2
    Phase-1 volume fraction = 0.405020248915  Min(alpha.water) = -4.20434479041e-19  Max(alpha.water) = 1.00017033508
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405020252161  Min(alpha.water) = -9.3402879368e-18  Max(alpha.water) = 1.00017033508
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 6.30171155038e-06, Final residual = 3.91016659198e-11, No Iterations 2
    Phase-1 volume fraction = 0.405026541074  Min(alpha.water) = -4.20021831096e-19  Max(alpha.water) = 1.00016679278
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405026544346  Min(alpha.water) = -9.00635424217e-18  Max(alpha.water) = 1.00016679278
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.91839029235e-05, Final residual = 1.82889065247e-07, No Iterations 217
    time step continuity errors : sum local = 5.34683280044e-08, global = -1.8534898982e-08, cumulative = 4.2268058243e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 4.10146448315e-06, Final residual = 7.84960249687e-10, No Iterations 343
    time step continuity errors : sum local = 2.11632749936e-10, global = -3.56510159845e-11, cumulative = 4.22677017328e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.000248019055085, Final residual = 6.07258962899e-09, No Iterations 10
    smoothSolver:  Solving for k, Initial residual = 0.00374092438787, Final residual = 8.09278671661e-09, No Iterations 25
    ExecutionTime = 193.37 s  ClockTime = 199 s
    
    forces forces1 write:
        Sum of forces
            Total    : (-0.000559450737003 5.7761890152e-23 531.613552613)
            Pressure : (-0.000559467123084 5.77618567618e-23 531.598688479)
            Viscous  : (1.63860806279e-08 3.33902769415e-29 0.0148641342046)
        Sum of moments
            Total    : (5.84142802294e-24 -0.000342896411982 -3.69197661426e-25)
            Pressure : (5.84142416828e-24 -0.000343009781452 -3.6918115851e-25)
            Viscous  : (3.85466373449e-30 1.13369470492e-07 -1.65029156861e-29)
    
    
    Courant Number mean: 0.00279112394805 max: 0.280523571301
    Interface Courant Number mean: 2.14046432716e-05 max: 0.11515053481
    deltaT = 0.00315723967303
    Time = 0.224752
    
    PIMPLE: iteration 1
    motion_.dropFlag: 0     
     时间 db().time().value():0.224752232432在算了
    forces forces:
        rho: rho
        Not including porosity effects
    
    6-DoF rigid body motion
        Centre of rotation: (0 0 -0.0217630478445)
        Centre of mass: (6.94248843292e-09 0 -0.00136304784445)
        Orientation: (1 0 3.40318060437e-07 0 1 0 -3.40318060437e-07 0 1)
        Linear velocity: (0 0 -0.114303683622)
        Angular velocity: (0 -1.23730660168e-05 0)
    cellVolumeWeight : detected 2 mesh regions
    
        zone:0 nCells:400000
        zone:1 nCells:17900
    Marking patch-cells on zone 0
    Marking patch-cells on zone 1
    
    After patch analysis : nCells : 417900
        other  : 412560
        patch  : 4744
        overset: 596
    
    Creating mesh-to-mesh addressing for region0 and region0 regions using cellVolumeWeight
    meshToMesh: Using AABBTree method
        Overlap volume: 0.133963754869
    cellVolumeWeight : detected 6 mesh regions after overset
    
    Front : fraction:1 size:1152
    Overset analysis : nCells : 417900
        calculated   : 411612
        interpolated : 946
        hole         : 5342
    
    Updating StokesII wave model for patch inlet
    Updating shallowWaterAbsorption wave model for patch outlet
    Execution time for mesh.update() = 5.26 s
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 8.27900604098e-06, Final residual = 6.17976459119e-11, No Iterations 2
    Phase-1 volume fraction = 0.405035205736  Min(alpha.water) = -4.2000085271e-19  Max(alpha.water) = 1.00016302516
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405035217259  Min(alpha.water) = -2.06357338121e-11  Max(alpha.water) = 1.00016302516
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 8.28041738898e-06, Final residual = 6.17451639143e-11, No Iterations 2
    Phase-1 volume fraction = 0.405043492314  Min(alpha.water) = -4.19979866278e-19  Max(alpha.water) = 1.00015934263
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405043502608  Min(alpha.water) = -2.26450127421e-11  Max(alpha.water) = 1.00015934263
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 0.000150036625369, Final residual = 1.45159590137e-06, No Iterations 196
    time step continuity errors : sum local = 3.70909972221e-07, global = 7.26651342258e-09, cumulative = 4.23403668671e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.30341145831e-05, Final residual = 8.03891696424e-10, No Iterations 312
    time step continuity errors : sum local = 1.84232683708e-09, global = -7.72146104571e-10, cumulative = 4.2332645406e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.00803589890024, Final residual = 8.77395628444e-09, No Iterations 19
    smoothSolver:  Solving for k, Initial residual = 0.0815456954399, Final residual = 9.97858516161e-09, No Iterations 37
    PIMPLE: iteration 2
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 1.25025795449e-05, Final residual = 1.28360668614e-10, No Iterations 2
    Phase-1 volume fraction = 0.405041757133  Min(alpha.water) = -3.9950474753e-19  Max(alpha.water) = 1.00016303139
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405041775746  Min(alpha.water) = -2.25147901429e-11  Max(alpha.water) = 1.00016303139
    Updating StokesII wave model for patch inlet
    smoothSolver:  Solving for alpha.water, Initial residual = 1.48571656776e-05, Final residual = 1.66018980762e-10, No Iterations 2
    Phase-1 volume fraction = 0.405056602162  Min(alpha.water) = -3.99504056785e-19  Max(alpha.water) = 1.00015935482
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    MULES: Correcting alpha.water
    Phase-1 volume fraction = 0.405056617384  Min(alpha.water) = -2.39922481886e-11  Max(alpha.water) = 1.00015935482
    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.93785486005e-05, Final residual = 1.80133042219e-07, No Iterations 233
    time step continuity errors : sum local = 1.49119064311e-07, global = 8.55835392808e-08, cumulative = 4.31884807988e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 4.34233095881e-06, Final residual = 9.65565903777e-10, No Iterations 248
    time step continuity errors : sum local = 6.94097054035e-10, global = 3.54454383188e-10, cumulative = 4.31920253427e-06
    smoothSolver:  Solving for epsilon, Initial residual = 0.000836889766811, Final residual = 5.92685657735e-09, No Iterations 14
    smoothSolver:  Solving for k, Initial residual = 0.012586335727, Final residual = 8.66251132093e-09, No Iterations 30
    ExecutionTime = 199.97 s  ClockTime = 206 s
    
    forces forces1 write:
        Sum of forces
            Total    : (-0.00011004169385 1.37786971216e-23 1219.0661049)
            Pressure : (-0.000109960701429 1.37785132112e-23 1219.03338896)
            Viscous  : (-8.09924212441e-08 1.83910373603e-28 0.0327159413621)
        Sum of moments
            Total    : (1.31672825707e-24 -0.000139279778531 9.42547042748e-25)
            Pressure : (1.31671152789e-24 -0.000139418577671 9.42490708219e-25)
            Viscous  : (1.67291810988e-29 1.38799140267e-07 5.63345285421e-29)
    
    


  • @tower 老哥,不知道你找到问题原因没有?:135: 求分享!我是模拟波物相互作用问题的,对你遇到的这个问题很好奇o_o



  • @xiezhuoyu 没有:135: 如果解决了 会在这里贴上结果的



  • @tower 老哥,我也遇到了同样的问题:136:
    用overset,浮体z方向受力正负交替变化,然后越来越大。
    我看结果文件是因为浮体底部的压力变化剧烈,忽正忽负。所以想着加密一下浮体附近的网格,试试能不能解决问题。
    可是!我加密网格后,浮体壁面的Y+小于30了(浮体顶部(接触空气的部分)尤其小),其实我的网格也不是很密,网格尺寸大概就是浮体吃水的1/8,而且如果可能的话,我想用壁面函数啊,请问,老哥你遇到这种问题一般如何解决?谢谢
    也希望有其他前辈能够指教!谢谢



  • @xiezhuoyu 我也询问过别人,给的建议也是加密网格,但是我试着加密了下,还是相同的错误。 其实我不是很理解的是,从我po在上面的log文件来看压力虽然迭代的次数多,但是最终残差不是已经满足条件了吗,为何压力积分后的力还会不准确,出现这种震荡问题呢



  • 最近在做一个波浪中物体二自由度的运动案例,最开始使用普通的动网格来计算的,因为计算幅度可以接受,但是结果却发现在开始计算0.2s左右,计算就发散了,发散的原因是物体Z方向上的速度急剧增大,

    这个算例要是小的话,可以发上来给你看看



  • 多谢@东岳老师,我把动网格和overset的案例文件都上传了,您看一下。
    动网格我是用的waves2foam+v1712的组合 overset用的1906的版本
    overset: oversetMesh.zip
    动网格: dynamicMesh.zip
    :baobao:



  • 各位,
    我尝试增大PIMPLE里面循环次数来增加p_rgh的迭代次数,但是发现每次迭代的次数还是很多 不是一个递减的趋势
    如下:

    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 8.72710724614e-07, Final residual = 8.72514217379e-09, No Iterations 382
    time step continuity errors : sum local = 7.03336340027e-09, global = 1.9150124018e-09, cumulative = 3.04929773866e-07
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 3.69104939702e-07, Final residual = 1.44876414351e-09, No Iterations 335
    time step continuity errors : sum local = 1.11124908301e-09, global = 1.95050292461e-10, cumulative = 3.05124824159e-07
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 2.2782727071e-07, Final residual = 1.06023228234e-09, No Iterations 607
    time step continuity errors : sum local = 7.68585702259e-10, global = -3.36686161497e-10, cumulative = 3.04788137997e-07
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.47947887396e-07, Final residual = 9.72671115058e-10, No Iterations 464
    time step continuity errors : sum local = 6.73366904995e-10, global = 7.62059709157e-11, cumulative = 3.04864343968e-07
    smoothSolver:  Solving for epsilon, Initial residual = 0.000146170038677, Final residual = 5.6866402182e-09, No Iterations 8
    smoothSolver:  Solving for k, Initial residual = 0.00238502525139, Final residual = 9.25193944196e-09, No Iterations 20
    ExecutionTime = 689.06 s  ClockTime = 695 s
    

    尝试修改为层流之后,连续迭代,次数基本成一个下降趋势,但是受力情况还是不变,错误依旧

    如下:

    Updating StokesII wave model for patch inlet
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.33810842593e-07, Final residual = 1.05803239609e-09, No Iterations 95
    time step continuity errors : sum local = 2.20723157353e-08, global = 6.73895228141e-09, cumulative = 7.30414848751e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 8.58642796578e-09, Final residual = 9.05674029848e-10, No Iterations 23
    time step continuity errors : sum local = 1.87310827339e-08, global = 5.04129159013e-09, cumulative = 7.3091897791e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.88155187954e-09, Final residual = 9.84985998753e-10, No Iterations 1
    time step continuity errors : sum local = 1.99973561049e-08, global = 4.66563789626e-09, cumulative = 7.313855417e-06
    DILUPBiCGStab:  Solving for p_rgh, Initial residual = 1.11812493747e-09, Final residual = 9.39334225107e-10, No Iterations 1
    time step continuity errors : sum local = 1.91664654171e-08, global = 4.75521938246e-09, cumulative = 7.31861063638e-06
    ExecutionTime = 8152.77 s  ClockTime = 8159 s


  • 我这没装wave2foam,所以.. :135: 看看其他大佬有什么意见



  • 虽然我算例的浮体和你不一样,但是问题很类似:在波浪还没有传播到浮体附近之前,浮体就受力振荡,p_rgh的迭代次数不是递减的趋势,感觉我就是在踩你踩过的坑:135: @tower
    overset: oversetMesh.zip 这个算例用的是OF1906自带的造波消波模块吧,不需要waves2Foam造波消波,@东岳 老师能不能给我们一点建议o_0,看看应该从什么角度着手尝试解决这个问题?谢谢!
    也希望有其他前辈能够就这个问题指点一下,缩短小白踩坑的时间,感谢!!



  • 我用overset计算过浮体大幅度运动的问题,没遇到你们说的问题。
    第一种可能是设置问题,可以仔细检查一下算例的设置,包括overset网格的设置;
    第二中可能就是waves2Foam与overset网格结合的问题。这个我也不确定,因为我之前算的时候采用了自己写的造波程序。



  • @CFDngu 谢谢建议!!


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