Flotran中，温度加载出现问题。

aiyouguai

***error***

Negative or zero temperatures may be avoided by either mesh refinement or modified inertial relaxation especially if Petrov-Galerkin formulation is used for the energy equation.

请问这是什么原因造成的，如何解决。。。

各位大侠，这个问题很普遍，麻烦给大家想想办法。谢谢了！！

aiyouguai

流场模拟的命令，有啥问题哦。。。？
!!!!!!!!!!!!!!!!流场部分!!!!!!!!!!!!!!!!!!!!!   
PHYSCIS,CLEAR   
Finish  
/clear  
/PLOPTS,INFO,3  
/PLOPTS,LOGO,0  
/PLOPTS,WP,0
/PLOPTS,DATE,2  
/TRIAD,OFF  
/REPLOT
/RGB,INDEX,100,100,100, 0   
/RGB,INDEX, 80, 80, 80,13   
/RGB,INDEX, 60, 60, 60,14   
/RGB,INDEX, 0, 0, 0,15  
/UDOC,1,CNTR,RIGH   
/TITLE,Arc_Welding_Simulation1  
/FILNAME,Arc_Welding_Simulation1,0  
/REPLOT
/PREP7  
ET,1,FLUID142   
!等离子体
MPTEMP,1,273,2000,4000,6000,8000,10000  
MPTEMP,7,12000,14000,16000,18000,20000  
MPDATA,DENS,1,1,1.67,0.2,0.1216,0.08137,0.06094,0.04782
MPDATA,DENS,1,7,0.03627,0.02479,0.01731,0.01406,0.01227
MPDATA,KXX,1,1,0,6.920e-2,1.230e-1,1.660e-1,2.720e-1,6.250e-1   
MPDATA,KXX,1,7,1.403,2.297,2.315,2.294,2.644
MPDATA,C,1,1,521,521,521,521,633,1527   
MPDATA,C,1,7,4692,9388,7069,3113,2775   
MPDATA,VISC,1,1,2e-5,8.07e-5,1.57e-4,2.21e-4,2.56e-4,2.9e-4
MPDATA,VISC,1,7,2.45e-4,1.17e-4,4.46e-5,2.57e-5,2.3e-5  
MPDATA,RSVX,1,1,1000,100,7.84,0.0099,0.0011,3.663e-4
MPDATA,RSVX,1,7,2.1097e-4,1.4993e-4,1.2195e-4,1.0672e-4,9.6154e-5   
MPDATA,MURX,1,,1
!铜坩锅
MPDATA,DENS,2,,8960
MPDATA,RSVX,2,,16.73e-8
MPDATA,KXX,2,,401  
MPDATA,MURX,2,,1  
MPDATA,VISC,2,,1e10
!钛铸件
MPDATA,DENS,3,,4500
MPDATA,RSVX,3,,0.00000042
MPDATA,KXX,3,,21.9   
MPDATA,MURX,3,,1  
MPDATA,VISC,3,,1e10
/REPLOT,RESIZE  
TOFFST,0

CYLIND,0,0.16,-0.27,0.22,0,90
CYLIND,0,0.1,-0.27,0.22,0,90
CYLIND,0,0.18,-0.27,0.22,0,90
CYLIND,0,0.2,-0.27,0.22,0,90

vsbw,all         
wpoffs,0,0,0.1
vsbw,all
wpoffs,0,0,0.1
vsbw,all
wpoffs,0,0,-0.05
vsbw,all
wpoffs,0,0,-0.35
vsbw,all
wpoffs,0,0,-0.05
vsbw,all
VOVLAP,ALL  
VGLUE,ALL  
NUMCMP,ALL

/VIEW,1,-1,-1,1
/VUP,1,Z
APLOT   

ALLSEL
!等离子体
VSEL,S,VOLU,,2,4
VSEL,A,VOLU,,8
VSEL,A,VOLU,,10,13
VSEL,A,VOLU,,14,16
VSEL,A,VOLU,,18,22
VSEL,A,VOLU,,25
VSEL,A,VOLU,,28
VATT,1,,1,0
!铜坩锅
VSEL,S,VOLU,,7
VSEL,A,VOLU,,9
VSEL,A,VOLU,,17
VSEL,A,VOLU,,24
VSEL,A,VOLU,,26,27
VATT,2,,1,0,
!钛铸件
VSEL,S,VOLU,,1
VSEL,A,VOLU,,5,6
VSEL,A,VOLU,,23
VATT,3,,1,0,
ALLSEL
VSWEEP,ALL
VPLOT  
/REPLOT

/SOL
!!!!!!!!!!!!!!!!!!!定义速度载荷!!!!!!!!!!!!!!!!!!!!
!外围边界，定义固壁边界
ALLSEL,ALL
NSEL,S,LOC,Z,-0.27
NSEL,A,LOC,Z,0.22
CSYS,1
NSEL,A,LOC,X,0.2
CSYS,0
D,ALL,VX,0
D,ALL,VY,0
D,ALL,VZ,0
!两个电极，一个坩锅定义固壁边界
ALLSEL,ALL  
VSEL,S,VOLU,,1
VSEL,A,VOLU,,5,7
VSEL,A,VOLU,,9
VSEL,A,VOLU,,17
VSEL,A,VOLU,,23,24
VSEL,A,VOLU,,26,27
NSLV,S,1
D,ALL,VX,0
D,ALL,VY,0
D,ALL,VZ,0
!等离子体对称面定义对称边界
ALLSEL,ALL
ASEL,S,AREA,,21,22
ASEL,A,AREA,,30,31
ASEL,A,AREA,,42,43
ASEL,A,AREA,,53,54
ASEL,A,AREA,,61,62
ASEL,A,AREA,,65,66
ASEL,A,AREA,,69,70
ASEL,A,AREA,,73,74
ASEL,A,AREA,,77,78
ASEL,A,AREA,,81,82
ASEL,A,AREA,,84,85
ASEL,A,AREA,,90,91
ASEL,A,AREA,,94,101
ASEL,A,AREA,,109,110
ASEL,A,AREA,,115,116
NSLA,S,1
D,ALL,VX,0
D,ALL,VY,0
!!!!!!!!!!!!!!!!!!!定义温度载荷!!!!!!!!!!!!!!!!!!
!外围边界，定义室温
ALLSEL,ALL
VSEL,S,VOLU,,2,3
VSEL,A,VOLU,,10,15
VSEL,A,VOLU,,18,19
VSEL,A,VOLU,,21,22
VSEL,A,VOLU,,25
VSEL,A,VOLU,,28
NSLV,S,1
D,ALL,TEMP,300,0
!坩锅冷却，定义室温
ALLSEL,ALL
VSEL,S,VOLU,,7
VSEL,A,VOLU,,9
VSEL,A,VOLU,,17
VSEL,A,VOLU,,24
VSEL,A,VOLU,,26,27
NSLV,S,1
D,ALL,TEMP,300,0

ALLSEL,ALL  
FLDATA1,SOLU,TRAN,0
FLDATA1,SOLU,FLOW,1
FLDATA1,SOLU,TEMP,1
FLDATA1,SOLU,TURB,0
FLDATA1,SOLU,COMP,0
FLDATA1,SOLU,VOF,0  
FLDATA1,SOLU,SFTS,0
FLDATA1,SOLU,IVSH,0
FLDATA1,SOLU,SWRL,0
FLDATA1,SOLU,SPEC,0
FLDATA1,SOLU,ALE,0  
FLDATA1,SOLU,RDSF,1

/COM,,Steady State Analysis,0   
FLDATA12,PROP,DENS,16   
FLDATA13,VARY,DENS,1
FLDATA12,PROP,VISC,16   
FLDATA13,VARY,VISC,1
FLDATA12,PROP,COND,16   
FLDATA13,VARY,COND,1
FLDATA12,PROP,SPHT,16   
FLDATA13,VARY,SPHT,1

FLDATA7,PROT,DENS,TABLE
FLDATA8,NOMI,DENS,-1
FLDATA9,COF1,DENS,0
FLDATA10,COF2,DENS,0
FLDATA11,COF3,DENS,0
FLDATA7,PROT,VISC,TABLE
FLDATA8,NOMI,VISC,-1
FLDATA9,COF1,VISC,0
FLDATA10,COF2,VISC,0
FLDATA11,COF3,VISC,0
FLDATA12,PROP,IVIS  
FLDATA7,PROT,COND,TABLE
FLDATA8,NOMI,COND,-1
FLDATA9,COF1,COND,0
FLDATA10,COF2,COND,0
FLDATA11,COF3,COND,0
FLDATA7,PROT,SPHT,TABLE
FLDATA8,NOMI,SPHT,-1
FLDATA9,COF1,SPHT,0
FLDATA10,COF2,SPHT,0
FLDATA11,COF3,SPHT,0

ALLSEL,ALL
ACEL,0,0,9.8,   
LDREAD,FORC,,,,,Arc_Welding_Simulation1,RMG
LDREAD,HGEN,,,,,Arc_Welding_Simulation1,RMG
SOLVE

loveyuexing

我也遇到了同样的问题，楼主课解决了啊，大家指点一下啊