流固耦合分析实例

2016-09-20 by:CAE仿真在线来源:互联网

ANSYS+ FLUENT流-热-固多场耦合工程实践核心技术培训

length=2 !定义体各种变量参数,长宽高

width=3
height=2
/prep7
et,1,63   !选用壳模型
et,2,30   !选用FLUID30单元,用于流固耦合问题
r,1,0.01  增加实常数,壳厚为0.01
mp,ex,1,2e11
mp,nuxy,1,0.3
mp,dens,1,7800  !定义壳单元的各种单元属性
mp,dens,2,1000  !定义Acoustics材料来描述流体材料-水
mp,sonc,2,1400  !定义声单元声速
mp,mu,0,  !定义吸声系数
!
block,,length,,width,,height !建立长方体
esize,0.5
mshkey,1
!
type,1 !选择壳单元
mat,1
real,1
asel,u,loc,y,width   !选择面
amesh,all!划分面单元
alls !选择所有项
!
type,2   !选择声单元
mat,2
vmesh,all!划分体单元
fini

/solu
antype,2
modopt,unsym,10 !非对称模态提取方法处理流固耦合问题
eqslv,front
mxpand,10,,,1
nsel,s,loc,x,
nsel,a,loc,x,length
nsel,r,loc,y
d,all,,,,,,ux,uy,uz,
nsel,s,loc,y,width,
d,all,pres,0  !上面几步为定义边界条件和约束
alls
asel,u,loc,y,width,
sfa,all,,fsi  !定义流固耦合界面
alls !选择所有项
solv !求解
fini

/post1  !后处理
set,first
plnsol,u,sum,2,1   !显示图形
fini

/PREP7
!定义壳材料与性质
!壳元素与材料
ET,1,shell63 $MP,EX,1,201E9 $MP,prxy,1,0.26 $MP,dens,1,7.85E3 $r,1,0.006
!流体元素与材料
ET,2,FLUID80 $MP,EX,2,1.5e9 $MP,DENS,2,0.84e3 $mp,visc,2,1.0e-10

!以下这个keyoption怎么用? 如过用1,就会显示[Element 877 may not have a positive Z coordinate IF KEYOPT(2) = 1.],显示这个错误代表要做什么修正吗?所以我暂时用KEYOPT(2) = 0就可以跑。
KEYOPT,2,2,0

!建立壳关键点
K,1,10,0,0 $K,2,10,0,12

!建立中心线关键点
k,3,0,0,0 $k,4,0,0,20

!定义壳壁线
L,1,2 $L,1,3

!以关键点3,4为中心线旋转360度生成壳体
AROTAT,all,,,,,,3,4,360

!划分壳体网格
AATT,1,1,1 $esize,2 $mshape,0,3D $mshkey,2 $amesh,all $alls

!延伸出水位体积
VEXT,2,8,2,0,0,10,0,0,0 $vglue,all

csys,1
!划分水位网格
type,2 $mat,2 $esize,2 $mshape,0,3D $mshkey,1 $vmesh,all
alls
!以上建模应该没太大问题

!以下是耦合,我在流固界面上的网格是重合节点,特别是下面这两段落我很不确定该怎么设定,感觉问题就出在这边了!这里解决了应该就可以。要怎么改?或是用CP? 或是NUMMRG? 重点是流体和固体要一起动,通常设定不好就流体自己动,或是流体都跑到壳体外面去了,流体跟壳不应该穿越,而是一起有行为。
csys,1 !将工作平面定义为柱坐标。
nsel,s,loc,x,10
nrotate,all   !旋转节点坐标系。
CPINTF,UX,0.0001, !将径向约束(即X方向)加到节点上。

nsel,s,loc,z,0
nrotate,all
CPINTF,UZ,0.0001,

!边界条件,将底部固定,并给予Z方向加速度。
NSEL,S,LOC,Z,0 $D,ALL,ALL $acel,,,9.8

fini
/solu
antype,modal
modopt,reduc,10,,
mxpand,10,

csys,1!Z上柱坐标系
!定义主自由度,由图显示感觉是没问题,但我也不太确定。
Esel,s,type,,1  !选择壳
Nsle,s,all !所有点
Nsel,u,loc,z,0  !排除边界条件
m,all,ux   !(径向)x方向的主自由度

Esel,s,type,,2  !选择液体
Nsel,s,loc,z,10  !再选择液面表面
m,all,uz !(竖向)z方向的主自由度

alls
solve
fini

水坝空库
/BATCH
KEYW,PR_SET,1
KEYW,PR_STRUC,1
KEYW,PR_THERM,0
KEYW,PR_FLUID,0
KEYW,PR_ELMAG,0
KEYW,MAGNOD,0
KEYW,MAGEDG,0
KEYW,MAGHFE,0
KEYW,MAGELC,0
KEYW,PR_MULTI,0
KEYW,PR_CFD,0
/GO
!*

/prep7
!* define material proterties
mp,dens,1,2650. !mat 1 for dam
mp,ex,1,3.15e10
mp,prxy,1,.167

!* define element type
et,1,PLANE42,,,2

!* define geometry
lwater=618.
k, 1,0.0,0.0,0.0
k, 2,70.2,0.,0.
k, 3,0.,66.5,0.
k, 4,21.9875,66.5,0.
k, 5,0.,103.,0.
k, 6,14.8,103.,0.

a, 1, 2, 4, 3
a, 3, 4, 6, 5

asel,s,loc,x,0.,100.
aatt,1,,1
cm,adam,area

allsel,all

!* mesh geometry
ESIZE,0,10
lsel,s,loc,y,0.1,66.             !坝下部剖分分数
lesize,all,,,15

mshape,0,2D
mshkey,1
allsel,all
amesh,all

finish
/solu

antype,modal
MODOPT,LANB,30
MXPAND,30, , ,0

esel,s,mat,,1                      !坝体约束
nsle,s
nsel,r,loc,y,-1.0,1.0
d,all,ux,0.
d,all,uy,0.

/pbc,all,,1
/pnum,type,1
/number,1
gplot

allsel,all

save
solve

满库
/BATCH
KEYW,PR_SET,1
KEYW,PR_STRUC,1
KEYW,PR_THERM,0
KEYW,PR_FLUID,0
KEYW,PR_ELMAG,0
KEYW,MAGNOD,0
KEYW,MAGEDG,0
KEYW,MAGHFE,0
KEYW,MAGELC,0
KEYW,PR_MULTI,0
KEYW,PR_CFD,0
/GO
!*

/prep7
!* define material proterties
mp,dens,1,2650. !mat 1 for dam
mp,ex,1,3.15e10
mp,prxy,1,.167
mp,dens,2,1000. !mat 2 for water
mp,sonc,2,1440

!* define element type
et,1,PLANE42,,,2
et,2,29
et,3,29,,1

!* define geometry
lwater=618.
k, 1,0.0,0.0,0.0
k, 2,70.2,0.,0.
k, 3,0.,66.5,0.
k, 4,21.9875,66.5,0.
k, 5,0.,103.,0.
k, 6,14.8,103.,0.
k, 7,-1.*lwater,103.,0.
k, 8,-1.*lwater,66.5,0.
k, 9,-1.*lwater,0.,0.

a, 1, 2, 4, 3
a, 3, 4, 6, 5
a, 8, 3, 5, 7
a, 9,1, 3, 8

asel,s,loc,x,0.,100.
aatt,1,,1
cm,adam,area
asel,s,loc,x,-1*lwater,0.
aatt,2,,3
cm,awater,area

allsel,all

!* mesh geometry
ESIZE,0,10
lsel,s,loc,y,0.1,66.             !坝下部剖分分数
lesize,all,,,15
lsel,s,loc,x,-0.1,-1*lwater-1.             !水体长度方向剖分分数
lsel,r,loc,y,-0.1,67.
lesize,all,,,40,0.5
lsel,s,loc,x,-0.1,-1*lwater-1.             !水体长度方向剖分分数
lsel,r,loc,y,100.,104.
lesize,all,,,40,2.0

mshape,0,2D
mshkey,1
allsel,all
amesh,all

!更改与水体接触的单元类型
esel,s,type,,3
nsle,s
nsel,r,loc,x,-1.,1.
esln,r
emodif,all,type,2

allsel,all

finish
/solu

antype,modal
MODOPT,UNSYM,30
MXPAND,30, , ,0

/pnum,type,1
/number,1

nsel,s,loc,x,-1.,1.             !库水坝体FSI面
esln,s
esel,r,mat,,2
sf,all,fsi

esel,s,mat,,1                      !坝体约束
nsle,s
nsel,r,loc,y,-1.0,1.0
d,all,ux,0.
d,all,uy,0.

esel,s,mat,,2                      !水体表面约束
nsle,s
nsel,r,loc,y,102.,104.
d,all,pres,0.

/pbc,all,,1
/psf,fsi,,2

allsel,all
gplot

save
solve