ansys固液耦合實例

1、FSIsolveransys固液耦合2010-01-0315:24一般說來，ANSYS的流固耦合主要有4種方式：1，sequential這需要用戶進行APDL編程進行流固耦合；2，F(xiàn)SIsolver流固耦合的設(shè)置過程非常簡單，推薦你使用這種方式；3，multi-fieldsolver這是FSIsolver的擴展，你可以使用它實現(xiàn)流體，結(jié)構(gòu)，熱，電磁等的耦合；4，直接采用特殊的單元進行直接耦合，耦合計算直接發(fā)生在單元剛度矩陣。流固耦合的邊界應(yīng)用帶有SFIN標記的SF，SFA，SFE，SFL等命令來標記耦合界面，具體方法見ansyshelp很詳細的。固液耦合實例length=2width=3hei

2、ght=2/prep7et,1,63et,2,30!選用FLUID30單元，用于流固耦合問題r,1,0.01mp,ex,1,2e11mp,nuxy,1,0.3mp,dens,1,7800mp,dens,2,1000!定義Acoustics材料來描述流體材料-水mp,sonc,2,1400mp,mu,0,!block,length,width,heightesize,0.5mshkey,1!type,1mat,1real,1asel,u,loc,y,widthamesh,allalls!type,2mat,2vmesh,allfini/soluantype,2modopt,unsym,10!非對

3、稱模態(tài)提取方法處理流固耦合問題eqslv,frontmxpand,10,1nsel,s,loc,x,nsel,a,loc,x,lengthnsel,r,loc,yd,all,ux,uy,uz,nsel,s,loc,y,width,d,all,pres,0allsasel,u,loc,y,width,sfa,all,fsi!定義流固耦合界面allssolvfini/post1set,firstplnsol,u,sum,2,1fini在渦集振動的計算過程中經(jīng)歷過若干警告和錯誤，小結(jié)如下：1，必須嚴格按照建模順序，先建立流體區(qū)域，后建立固體。2，實常數(shù)的指定，材料號的對應(yīng)，尤其是流體。3，關(guān)鍵在于流

4、固耦合界面的選擇和指定，難點則在于流體分析選項的設(shè)定。最近為了考慮結(jié)構(gòu)在水中的自振頻率，考察了一個簡單的例子，由于以前對流固耦合沒有接觸過，所以由很多疑問，請高手指教。例子是一圓環(huán)在水中的模態(tài)分析。命令流如下：finish/clear/PREP7!定義單元類型ET,1,PLANE42!structuralelementET,2,FLUID29!acousticfluidelementwithux&uyET,3,129!acousticinfinitelineelementr,3,0.31242,0,0ET,4,FLUID29,1,0!acousticfluidelementwithou

5、tux&uy!材料屬性MP,EX,1,2.068e11MP,DENS,1,7929MP,NUXY,1,0MP,DENS,2,1030MP,SONC,2,1460!創(chuàng)建四分之一模型CYL4,0,0,0.254,0,0.26035,90CYL4,0,0,0.26035,0,0.31242,90!選擇屬性,網(wǎng)格劃分ASEL,S,AREA,1AATT,1,1,1,0LESIZE,1,16,1LESIZE,3,16,1LESIZE,2,1,1LESIZE,4,1,1MSHKEY,1MSHAPE,0,2D!mappedquadmeshAMESH,1ASEL,S,AREA,2AATT,2,1,2,0

6、LESIZE,5,16,1LESIZE,7,16,1LESIZE,6,5LESIZE,8,5MSHKEY,0MSHAPE,0,2D!mappedquadmeshAMESH,2!關(guān)于Y軸鏡像nsym,x,1000,all!offsetnodenumberby1000esym,1000,all!關(guān)于y軸鏡像nsym,y,2000,all!offsetnodenumberby2000esym,2000,allNUMMRG,ALL!mergeallquantitiesesel,s,type,1nsle,sesln,s,0nsle,sesel,invensle,semodif,all,type,4ese

7、l,allnsel,all!指定無限吸收邊界csys,1nsel,s,loc,x,0.31242type,3real,3mat,2esurfesel,allnsel,all!標識流固交接面nsel,s,loc,x,0.26035esel,s,type,2sf,all,fsi,1nsel,allesel,allFINISH/soluantype,modalmodopt,damp,10mxpand,10,yessolvefinish為了便于對比，也對圓環(huán)在空氣中做了模態(tài)分析finish/clear/PREP7!定義單元類型ET,1,PLANE42!structuralelement!材料屬性MP,

8、EX,1,2.068e11MP,DENS,1,7929MP,NUXY,1,0!創(chuàng)建四分之一模型CYL4,0,0,0.254,0,0.26035,90!選擇屬性,網(wǎng)格劃分ASEL,S,AREA,1AATT,1,1,1,0LESIZE,1,16,1LESIZE,3,16,1LESIZE,2,1,1LESIZE,4,1,1MSHKEY,1MSHAPE,0,2D!mappedquadmeshAMESH,1!關(guān)于Y軸鏡像nsym,x,1000,all!offsetnodenumberby1000esym,1000,all!關(guān)于y軸鏡像nsym,y,2000,all!offsetnodenumberby2

9、000esym,2000,allNUMMRG,ALL/soluantype,modalmodopt,lanb,10mxpand,10,yessolvefinish在水中的自振頻率為SETTIME/FREQLOADSTEPSUBSTEPCUMULATIVE1-0.19544E-101112 0.29640E-031113-0.21663E-101224-0.29640E-0312250.30870E-0313360.00001337-0.30870E-0314480.00001449-0.53726E-03155100.57522E-11155110.53726E-0316612-0.89057

10、E-1116613 0.98059E-0117714 35.23217715 0.98059E-0118816 -35.23218817 0.98061E-0119918 35.23319919 0.98061E-011101020 -35.23311010在空氣中的自振頻率為SETTIME/FREQLOADSTEPSUBSTEPCUMULATIVE10.000011120.00001223 0.73609E-031334 60.8051445 60.8051556 172.971667 172.971778 334.401889 334.4019910 546.5911010主要有以下疑問：1）考慮流固耦合，做模態(tài)分析時流體單元是否只能用fluid29（2d）和fluid30（3d）,對于fluid129和fluid130在耦合中具體起到什么作用，能不能不設(shè)，而用邊界約束條件代替？2）流體范圍怎樣確定，如本例中（CYL4,0,0,0.26035Q0.31242,90）,外半徑為0.31242。如果不是環(huán)形的，如一塊當水板，該怎樣考慮？3）如果不考慮流體的壓縮性，把聲速設(shè)的很大，MRSONC,2,1e20，就可以了。4）從自振頻率可以看出，在水中和