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实例1:某一潜水艇可以简化为一圆筒,它由三层组成,最外面一层为不锈钢,中间为玻纤隔热层,最里面为铝层,筒内为空气,筒外为海水,求内外壁面温度及温度分布。几何参数:筒外径30feet总壁厚2inch不锈钢层壁厚0.75inch玻纤层壁厚1inch铝层壁厚0.25inch筒长200feet导热系数不锈钢8.27BTU/hr.ft.oF玻纤0.028BTU/hr.ft.oF铝117.4BTU/hr.ft.oF边界条件空气温度70oF海水温度44.5oF空气对流系数2.5BTU/hr.ft2.oF海水对流系数80BTU/hr.ft2.oF沿垂直于圆筒轴线作横截面,得到一圆环,取其中1度进行分析,如图示。/filename,Steady1/title,Steady-statethermalanalysisofsubmarine/units,BFTRo=15!外径(ft)Rss=15-(0.75/12)!不锈钢层内径ft)Rins=15-(1.75/12)!玻璃纤维层内径(ft)Ral=15-(2/12)!铝层内径(ft)Tair=70!潜水艇内空气温度Tsea=44.5!海水温度Kss=8.27!不锈钢的导热系数(BTU/hr.ft.oF)Kins=0.028!玻璃纤维的导热系数(BTU/hr.ft.oF)Kal=117.4!铝的导热系数(BTU/hr.ft.oF)Hair=2.5!空气的对流系数(BTU/hr.ft2.oF)Hsea=80!海水的对流系数(BTU/hr.ft2.oF)prep7et,1,plane55!定义二维热单元mp,kxx,1,Kss!设定不锈钢的导热系数mp,kxx,2,Kins!设定玻璃纤维的导热系数mp,kxx,3,Kal!设定铝的导热系数pcirc,Ro,Rss,-0.5,0.5!创建几何模型pcirc,Rss,Rins,-0.5,0.5pcirc,Rins,Ral,-0.5,0.5aglue,allnumcmp,arealesize,1,,,16!设定划分网格密度lesize,4,,,4lesize,14,,,5lesize,16,,,2Mshape,2!设定为映射网格划分mat,1amesh,1mat,2amesh,2mat,3amesh,3/SOLUSFL,11,CONV,HAIR,,TAIR!施加空气对流边界SFL,1,CONV,HSEA,,TSEA!施加海水对流边界SOLVE/POST1PLNSOL!输出温度彩色云图finish实例2一圆筒形的罐有一接管,罐外径为3英尺,壁厚为0.2英尺,接管外径为0.5英尺,壁厚为0.1英尺,罐与接管的轴线垂直且接管远离罐的端部。如图所示:罐内流体温度为华氏450度,与罐壁的对流换热系数年为250BUT/hr-ft2-oF,接管内流体的温度为华氏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70200300400500oF密度0.2850.2850.2850.2850.285lbm/in3导热系数8.358.909.359.810.23Btu/hr-ft-oF比热0.1130.1170.1190.1220.125Btu/lbm-oF对流系数*426405352275221Btu/hr-ft2-oF*接管内壁对流系数求罐与接管的温度分布。/prep7/title,Steady-statethermalanalysisofpipejunction/units,bin!使用英制单位et,1,90!定义热单元mp,dens,1,.285!密度mptemp,,70,200,300,400,500!建立温度表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!比热mpdata,hf,2,,426/144,405/144,352/144,275/144,221/144!接管对流系数!定义几何模型参数ri1=1.3!罐内半径ro1=1.5!罐外半径z1=2!罐长ri2=0.4!接管内半径ro2=0.5!接管外半径z2=2!接管长!建立几何模型cylind,ri1,ro1,,z1,,90!1/4罐体wprota,0,-90!将工作平面旋转到垂直于接管轴线cylind,ri2,ro2,,z2,-90!1/4接管wpstyl,defa!将工作平面恢复到默认状态vovlap,1,2!进行OVERLAP布尔操作/pnum,volu,1!打开实体编号/view,,-3,-1,1!定义显示角度/type,,4/title,Volumesusedinbuildingpipe/tankjunctionvplot!显示实体vdele,3,4,,1!删除多余实体!划分网格asel,,loc,z,z1!选择罐上Z=Z1的面asel,a,loc,y,0!添加选择罐上Y=0的面cm,aremote,area!创建名为AREMOTE的面组/pnum,area,1/pnum,line,1/title,linesshowingtheportionbeingmodeledaplot/noeraselplot/eraseaccat,all!组合罐远端的面及线,为映射划分网格作准备lccat,12,7lccat,10,5lesize,20,,,4!在接管壁厚方向分4等分lesize,40,,,6!在接管长度方向分6等分lesize,6,,,4!在罐壁厚方向分4等分allsel!选择EVERYTHINGesize,0.4!设定默认的单元大小mshape,0,3d!选择3D映射网格mshkey,1!保存数据文件vmesh,all!划分网格,产生节点与单元/pnum,defa/title,elementsinportionbeingmodeledeplot!显示单元finish!加载求解/soluantype,static!定义为稳态分析nropt,auto!设置求解选项为Program-chosen!Newton-Raphsontunif,450!设定初始所有节点温度csys,1!变为柱坐标nsel,s,loc,x,ri1!选择罐内表面的节点sf,all,conv,250/144,450!定义对流边界条件cmsel,,aremote!选择AREMOTE面组nsla,,1!选择属于AREMOTE面组的节点d,all,temp,450!定义节点温度wprota,0,-90!将工作平面旋转到垂直于接管轴线cswpla,11,1!创建局部柱坐标nsel,s,loc,x,ri2!选择接管内壁的节点sf,all,conv,-2,100!定义对流边界条件allsel!选择EVERYTHING/pbc,temp,,1!显示所有温度约束/psf,conv,,2!显示所有对流边界/title,Boundaryconditionsnplot!显示节点wpstyle,defa!工作平面恢复默认状态csys,0!变为直角坐标autots,on!打开自动步厂长nsubst,50!设定子步数量kbc,0!设定为阶越outpr,nsol,last!设置输出solve!进行求解finish!进入后处理/post1/title,Temperaturecontroursatpipe/tankjunctionplnsol,temp!显示温度彩色云图finish/exit,all实例1一个30公斤重、温度为70℃的铜块,以及一个20公斤重、温度为80℃的铁块,突然放入温度为20℃、盛满了300升水的、完全绝热的水箱中,如图所示。过了一个小时,求铜块与铁块的最高温度(假设忽略水的流动)。材料热物理性能如下:/filename,transient1/title,ThermalTransientExercise1!进入前处理/prep7et,1,plane77!定义单元类型mp,kxx,1,383!定义材料热性能参数mp,dens,1,8889!1~铜,2~铁,3~水mp,c,1,390mp,kxx,2,70mp,dens,2,7837mp,c,2,448mp,kxx,3,0.61mp,dens,3,996mp,c,3,4185rectnag,0,0.6,0,0.5!创建几何实体rectang,0.15,0.225,0.225,0.27rectang,0.6-0.2-0.058,0.6-0.2,0.225,0.225+0.044aovlap,all!布尔操作/pnum,area,1aplotaatt,1,1,1!划分网格eshape,2esize,0.02amesh,2aatt,2,1,1amesh,3aatt,3,1,1eshape,3esize,0.05amesh,4/pnum,mat,1eplotfinish!加载求解/soluantype,transtimint,off!先作稳态分析,确定初始条件time,0.01!设定只有一个子步的时间很小的载荷步deltim,0.01esel,s,mat,,3nsle,sd,all,temp,20esel,s,mat,,2nsle,sd,all,temp,80esel,s,mat,,1nsle,sd,all,temp,70allselsolve!得到初始温度分布time,3600!进行瞬态分析timint,on!打开时间积分deltim,26,2,200!设置时间步长,最大及最小时间步长autots,on!打开自动时间步长?ddelet,all,temp!删除稳态分析中定义的节点温度outres,all,1!将每个子步的值写入数据库文件solvefinishsave!进入POST26后处理/post26solu,2,dtime,,dtime!2~每一子步采用的时间步长nsol,3,node(0.1875,0.2475,0),temp,,T_Copper!3~铜块的中心点nsol,4,node(0.371,0.247,0),temp,,T_Iron!4~铁块的中心点nsol,5,node(30,0,0),temp,,T_H2O_Bot!5~水箱的底部nsol,6,node(30,50,0),temp,,T_H2O_Top!6~水箱的顶部nsol,7,node(0,25,0),temp,,T_H2O_Left!7~水箱的左部nsol,8,node(60,25,0),temp,,T_H2O_Right!8~水箱的右部Plvar,2plvar,3,4,5,6,7,8finish!进入POST26后处理/post26solu,2,dtime,,dtime!2~每一子步采用的时间步长nsol,3,node(0.1875,0.2475,0),temp,,T_Copper!3~铜块的中心点nsol,4,node(0.371,0.247,0),temp,,T_Iron!4~铁块的中心点nsol,5,node(30,0,0),temp,,T_H2O_Bot!5~水箱的底部nsol,6,node(30,50,0),temp,,T_H2O_Top!6~水箱的顶部nsol,7,node(0,25,0),temp,,T_H2O_Left!7~水箱的左部nsol,8,node(60,25,0),temp,,T_H2O_Right!8~水箱的右部Plvar,2plvar,3,4,5,6,7,8finish砂模外边界的对流边界条件:对流系数0.014Btu/hr.in2.oF,空气温度80oF;求3个小时后铸钢及砂模的温度分布。/Title,CastingSolidification!进入前处理/prep7et,1,plane55!定义单元mp,dens,1,0.054!定义砂模热性能mp,kxx,1,0.025mp,c,1,0.28mptemp,1,0,2643,2750,2875!定义铸钢的热性能mpdata,kxx,2,1.44,1
本文标题:四个ANSYS热分析经典例子
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