度为华氏100度,与管壁的对流换热系数随管壁温度而变。接管与罐为同一种材料，它的热物理性能如下表所示： 温度 密度 导热系数 比热 对流系数* 70 0.285 8.35 0.113 426 200 0.285 8.90 0.117 405 300 0.285 9.35 0.119 352 400 0.285 9.8 0.122 275 500 0.285 10.23 0.125 221 oF lbm/in3 Btu/hr-ft-oF Btu/lbm-oF Btu/hr-ft2-oF *接管内壁对流系数 求罐与接管的温度分布。 以下分别列出LOG文件及菜单操作
/prep7
/title,Steady-state thermal analysis of pipe junction /units,bin et,1,90
！使用英制单位
！定义热单元
！建立温度表
！比热
！密度
mp,dens,1,.285
mptemp,,70,200,300,400,500
mpdata,kxx,1,,8.35/12,8.90/12,9.35/12,9.80/12,10.23/12 ！导热系数 mpdata,c,1,,0.133,0.177,0.119,0.122,0.125 ！定义几何模型参数 ri1=1.3 z1=2 ri2=0.4 z2=2
！罐内半径
ro1=1.5
！罐外半径 ！罐长
！接管内半径 ！接管外半径 ！接管长
！1/4罐体
mpdata,hf,2,,426/144,405/144,352/144,275/144,221/144 ！接管对流系数
ro2=0.5
！建立几何模型 cylind,ri1,ro1,,z1,,90 wprota,0,-90 wpstyl,defa vovlap,1,2
cylind,ri2,ro2,,z2,-90
！将工作平面旋转到垂直于接管轴线 ！1/4接管
！将工作平面恢复到默认状态 ！打开实体编号 ！定义显示角度
！进行OVERLAP布尔操作
/pnum,volu,1 /view,,-3,-1,1
/type,,4
/title, Volumes used in building pipe/tank junction vplot
！显示实体
！删除多余实体 ！选择罐上Z=Z1的面 ！添加选择罐上Y=0的面 ！创建名为AREMOTE的面组
vdele,3,4,,1 ！划分网格 asel,,loc,z,z1 asel,a,loc,y,0 cm,aremote,area /pnum,area,1
/pnum,line,1
/title,lines showing the portion being modeled aplot /noerase lplot /erase accat,all lccat,12,7 lccat,10,5 lesize,20,,,4 lesize,40,,,6 lesize,6,,,4 allsel
esize,0.4 mshape,0,3d mshkey,1 save
vmesh,all
！在接管壁厚方向分4等分 ！在接管长度方向分6等分 ！在罐壁厚方向分4等分
！组合罐远端的面及线，为映射划分网
！格作准备
！选择EVERYTHING ！设定默认的单元大小
！保存数据文件
！划分网格，产生节点与单元
！选择3D映射网格
/pnum,defa
/title, elements in portion being modeled eplot finish ！加载求解 /solu
！定义为稳态分析
！Newton-Raphson
tunif,450 csys,1
！设定初始所有节点温度
！变为柱坐标
！选择罐内表面的节点 ！定义对流边界条件
！选择属于AREMOTE面组的节点 ！定义节点温度
！将工作平面旋转到垂直于接管轴线 ！创建局部柱坐标 ！选择接管内壁的节点 ！定义对流边界条件 ！显示所有温度约束 ！显示所有对流边界
！设置求解选项为Program-chosen
antype,static nropt,auto
！显示单元
nsel,s,loc,x,ri1 cmsel,,aremote nsla,,1
d,all,temp,450 wprota,0,-90 cswpla,11,1
sf,all,conv,250/144,450
！选择AREMOTE面组
nsel,s,loc,x,ri2 sf,all,conv,-2,100 allsel
/pbc,temp,,1 /psf,conv,,2 nplot
！选择EVERYTHING
/title,Boundary conditions
！显示节点
wpstyle,defa csys,0
autots,on nsubst,50 kbc,0 solve finish ！进入后处理
！工作平面恢复默认状态 ！变为直角坐标
！打开自动步厂长 ！设定子步数量
！设定为阶越 ！设置输出
outpr,nsol,last
！进行求解
/post1
/title,Temperature contrours at pipe/tank junction plnsol,temp finish /exit,all 菜单操作
！显示温度彩色云图
1、设定标题:Utility Menu>File>Change Title,输入Steady-State analysis of pipe junction,选择OK; 2、设定单位制:在命令提示行输入/UNITS,BIN;
3、定义单元类型:Main Menu>Preprocesor>Element Type>Add/Edit/Delete,选择Thermal Solid,
Bricck 20 node 90号单元;
4、定义材料属性
(1)Main Menu>Preprocessor>Material Props>-Constant->Isotropic,默认材料编号1,在
DENSITY框中输入0.285;
(2)Main Menu>Preprocessor>Material Props>-Temp Dependent->Temp Table,输入温度
70,200,300,400,500;
(3)Main Menu>Preprocessor>Material Props>-Temp Dependent->Prop Table,选择导热系数
KXX,材料编号为1,输入与温度表对应的导热系数8.35/12,8.9/12,9.35/12,9.8/12,10.23/12,选择APPLY;
(4)选择比热C,材料编号为1,输入0.113,0.117,0.119,0.122,0.125,选择APPLY;
(5)选择对流系数HF,材料编号为2,输入426/144,405/144,352/144,275/144, 221/144，选择
OK。
5、定义几何模型参数：Utility Menu>Parameters>Scalar Parameters,输入
ri1=1.3,ro1=1.5,z1=2,ri2=0.4,ro2=0.5,z2=2;
6、建立几何模型
(1)Main Menu>Preprocessor>-Modeling->Create>-Volumes->Cylinder>By
Dimensions, Outer radius框中输入ro1,Optional inner radium框中输入ri1,Z coordinates框中输
入0和Z1,Ending angle框中输入90;
(2)Utility Menu>WorkPlane>Offset WP by Increments,在XY,YZ,ZX框中输入0,-90; (3)Main Menu>Preprocessor>-Modeling->Create>-Volumes->Cylinder>By
Dimensions; Outer radius框中输入ro2, Optional inner radium框中输入ri2, Z coordinates框中
输入0和Z2,Starting angle框中输入-90,Ending angle框中输入0;
(4)Utility Menu>WorkPlane>Align WP with>Global Cartesian；
7、进行布尔操作:Main Menu>Preprocessor>-Modeling->Operate>-Booleans->
Overlap >Volumes,选择Pick All；
8、观察几何模型
(1)Utility Menu>PlotCtrls>Numbering,打开volumes;
(2)Utility Menu>PlotCtrls>View Direction, 在Coords of view point框中输入-3,-1,1； 9、 删除多余实体Main Menu>Preprocessor>-Modeling->Delete>Volume and Below,在命令输入
行输入3,4回车；
10、
创建组AREMOTE
Z1,选择APPLY,Y Coordinates, 在Min, Max框中输入0,OK;
(1)Utility Menu>Select>Entities,选择Area, By location, Z Coordinates, 在Min, Max框中输入(2)Utility Menu>Select>Comp/Assembly>Create Component,在Component name框中输入
AREMOTE, 在Components is made of菜单中选择AREA；
11、组合面及线
(1)Main Menu>Preprocessor>-Meshing->Mesh>-Volumes->Mapped>
-Concatenate->Area,选择Pick all；
(2)Main Menu>Preprocessor>-Meshing->Mesh>-Volumes->Mapped>
-Concatenate->Lines,在命令行中输入12,7回车,选择APPLY,在命令行中输入10,5回车,OK；
12、设定网格密度
(1)Main Menu>Preprocessor>-Meshing->Size Cntrls>Picked Lines,选择线6和20,OK,在No.
of element divisions框中输入4,OK；
(2)Main Menu>Preprocessor>-Meshing->Size Cntrls>Picked Lines,选择线40,OK,在No. of
element divisions框中输入6,OK；
(3)Utility Menu>Select>Everything；
(4)Main Menu>Preprocessor>-Meshing->Size Cntrls>-Global->Size,在element edge length框
中输入0.4,OK；
13、划分网格:Main Menu>Preprocessor>-Meshing->Mesh>-Volumes->Mapped>4 to 6 sides,选择
Pick All；
14、定义求解类型及选项
(1)Main Menu>Solution>-Analysis Type->New Analysis,选择Steady-State； (2)Main Menu>Solution>-Analysis Options,选择Program-chosen； 15、施加对流载荷
(1)Utility Menu>WorkPlane>Change Active CS to>Global Cylindrical；
(2)Utility Menu>Select>Entities,选择Nodes, By location, X,在Min, Max框中输入ri1,OK； (3)Main Menu>Solution>-Loads->Apply>-Thermal->Convection>On Nodes,选择Pick All, 输
入250/144及450,OK；
16、在AREMOTE组上施加温度约束
(1)Utility Menu>Select>Comp/Assembly>Select Comp/Assembly,选aremote; (2)Utility Menu>Select>Entities,选择Nodes, Attached to, On the Area all, OK；
(3)Main Menu>Solution>-Loads->Apply>-Thermal->Temperature>On Nodes,选择Pick all,输
入45,OK；
17、施加与温度有关的对流边界条件
(1)Utility Menu>WorkPlane>Offset WP by Increments,在XY,YZ,ZX Angles框中输入
0,-90,OK;
(2)Utility Menu>WorkPlane>Local Coordinate Systems>Create Local CS>At WP Origin,在
Type of coordinate system菜单中,选择Cylindrical 1,OK；
(3)Utility Menu>Select Entities,选择Nodes, By location, X, 在Min, Max框中输入ri2,OK； (4)Main Menu>Solution>-Loads->Apply>-Thermal->Convection>On Nodes,选择Pick All,在
Film coefficient框中输入-2,在Bulk temperature框中输入100,OK;
(5)Utility Menu>Select>Everything；
(6)Utility Menu>PlotCtrls>Symbols,在Show pres and convect as菜单中选择Arrow, OK; (7)Utility Menu>Plot>Nodes； 18、恢复工作平面及坐标系统
(1)Utility Menu>WorkPlane>Change Active CS to>Global Cartesian； (2)Utility Menu>WorkPlane>Align WP with>Global Cartesian； 19、设定载荷步选项:
Main Menu>Solution>-Load Step Options->Time/Frequenc>Time and Substeps,在Number of
substeps框中输入50,设置Automatic time stepping为On；
20、求解:Main Menu>Solution>-Solve->Current LS
21、显示温度分布彩色云图: Main Menu>General Postproc>Plot Results>-Contour Plot->Nodal
Solu,选择Temperature TEMP。
《ANSYS Verification Manual》中关于稳态热分析的实例：
VM58 VM92 VM93 VM94 VM95 VM96 VM97 VM98 VM99
Centerline temperature of a heat generating wire Insulted wall temperature
Temperature dependent conductivity Heat generating plate
Heat transfer from a cooling spine
Temperature distribution in a short solid cylinder Temperature distribution along a straight fin Temperature distribution along a tapered fin Temperature distribution in a trapezoidal fin
VM100 VM101 VM102 VM103 VM105 VM108 VM118 VM160 VM161 VM162
Heat conductivity across a chimney section Temperature distribution in a short solid cylinder Cylinder with temperature dependent conductivity Thin plate with a central heat source
Heat generation coil with temperature dependent conductivity Temperature gradient across a solid cylinder Centerline temperature of a heat generating wire Solid cylinder with harmonic temperature load Heat flow from a insulated pipe
Cooling of a circular fin of rectangular profile