/COM,ANSYS MEDIA REL. 2024R2 (05/10/2024) REF. VERIF. MANUAL: REL. 2024R2 /VERIFY,VM283 /TITLE,VM283,Low Reduced Frequency Model for Visco-thermal Fluid with Thin Structure /COM, /COM, REFERENCE: /COM, W. M. BELTMAN, "Viscothermal Wave Propagation Including Acousto-elastic Interaction", /COM, THESIS, SECTION6.3, PP128-136, ISBN 90-3651217-4, 1998. /COM, /PREP7 ET,1,FLUID30,,1 ! FLUID30 ELEMENTS, NO FSI ET,2,SOLSH190 ! SOLIDSHELL190 ELEMENTS ET,3,FLUID30,,0 ! FLUID30 ELEMENTS, WITH FSI /COM, MATERIAL PROPERTIES FOR AIR rho = 1.2 ! DENSITY c0 = 340 ! SOUND SPEED visc = 18.2e-6 ! DYNAMIC VISCOSITY kxx = 25.6e-3 ! THERMAL CONDUCTIVITY Cp = 1004 ! SPECIFIC HEAT Cv = 1004/1.4 z0 = rho*c0 WL=c0/300 H=WL/15 tp1 = 1e-3 tp2 = 2e-3 h0 = 1e-3 LX = 245e-3 LY = 122.5e-3 ZA = 0.5 ! HEIGHT OF ROOM A ZB = 2.0 ! HEIGHT OF ROOM B TB,AFDM,1,,,MAT ! ACOUSTIC FREQUENCY-DEPENDENT MATERIAL PROPERTIES TBDATA,1,rho,c0,visc,kxx,Cp,Cv TB,AFDM,1,,,THIN ! ACOUSTIC FREQUENCY-DEPENDENT THIN LAYER TBDATA,1,2*h0 /COM, MATERIAL PROPERTIES FOR ALUMINIUM PLATE MP,DENS,2,2710 ! DENSITY MP,EX,2,70.e9 ! ELASTIC MODULUS MP,NUXY,2,0.3 ! POISSON'S RATIO MP,DENS,3,rho MP,SONC,3,c0 *DIM,zz,ARRAY,6 zz(1)=0 zz(2)=zz(1)+zb zz(3)=zz(2)+tp2 zz(4)=zz(3)+2*h0 zz(5)=zz(4)+tp1 zz(6)=zz(5)+za *DO,i,1,5 BLOCK,-LX,LX,-LY,LY,zz(i),zz(i+1) *ENDDO VGLUE,ALL SHPP,OFF,ALL LSEL,S,LOC,Y,0 LESIZE,ALL,,,1 ALLSEL,ALL VSEL,S,LOC,Z,zz(3),zz(4) LESIZE,67,,,4 ESIZE,LX/10 TYPE,1 MAT,1 /OUT,SCRATCH VMESH,ALL VSEL,S,LOC,Z,zz(2),zz(3) VSEL,A,LOC,Z,zz(4),zz(5) TYPE,2 MAT,2 LESIZE,61,,,3 LESIZE,69,,,3 VEORIENT,6,THIN VEORIENT,8,THIN VMESH,ALL VSEL,S,LOC,Z,zz(1),zz(2) TYPE,1 MAT,3 ESIZE,(zz(2)-zz(1))/15 VMESH,ALL ALLSEL,ALL VSEL,S,LOC,Z,zz(5),zz(6) ESIZE,(zz(6)-zz(5))/10 VMESH,ALL ALLSEL,ALL NSEL,S,LOC,Y,-ly NSEL,A,LOC,Y,ly D,ALL,UY ALLSEL,ALL NSEL,S,LOC,Z,zz(2) NSEL,A,LOC,Z,zz(3) NSEL,A,LOC,Z,zz(4) NSEL,A,LOC,Z,zz(5) ESLN,S,0 ESEL,U,TYPE,,2 EMODIF,ALL,TYPE,3 ALLSEL,ALL ESEL,S,TYPE,,3 NSLE,S NSEL,S,LOC,Z,zz(2) NSEL,A,LOC,Z,zz(3) NSEL,A,LOC,Z,zz(4) NSEL,A,LOC,Z,zz(5) ESEL,S,TYPE,,2 NSLE,R ESEL,S,TYPE,,3 SF,ALL,FSI ! FLUID SOLID INTERACTION ALLSEL,ALL NSEL,S,LOC,Z,zz(2) NSEL,A,LOC,Z,zz(5) NSEL,R,LOC,X,LX D,ALL,UZ,0,,,,UX,UY ALLSEL,ALL NSEL,S,LOC,Z,zz(2) NSEL,A,LOC,Z,zz(5) NSEL,R,LOC,X,-LX D,ALL,UZ,0,,,,UX,UY ALLSEL,ALL NSEL,S,LOC,Z,zz(6) SF,ALL,PORT,1 ! PORT NUMBER NSEL,R,LOC,X,LX !BF,ALL,JS,1 ! MASS SOURCE RATE BF,ALL,MASS,1 ALLSEL,ALL NSEL,S,LOC,Z,zz(1) SF,ALL,IMPD,z0 ! IMPEDANCE SF,ALL,PORT,2 ! PORT NUMBER CM,N_IMPD,node ALLSEL,ALL FINISH /SOLUTION EQSLV,SPARSE ! SPARSE SOLVER ANTYPE,HARMIC ! HARMONIC ANALYSIS HROPT,FULL ! FULL METHOD HARFRQ,0,300 ! EXCITATION FREQUENCY NSUB,150 ! NUMBER OF SUBSTEPS SOLVE FINISH *CREATE,MYPOST,MAC *GET,AR80,NODE,,COUNT AR70=0 AR71=0 *DO,AR99,1,AR80 AR70=NDNEXT(AR70) AR71=AR71+PRES(AR70) *ENDDO AVG_PRES=AR71/AR80 *END /POST1 SET,LAST *GET,NUM_LSTEP,ACTIVE,0,SET,SBST VSEL,S,LOC,Z,zz(5),zz(6) ALLSEL,BELOW,VOLU CM,N_ROOMA,NODE ALLSEL,ALL /COM, ---Freq (Hz) Computed TL--- /COM, /NOPR *DO,AR99,1,NUM_LSTEP SET,1,AR99,,AMPL *GET,Freq,ACTIVE,,SET,FREQ CMSEL,S,N_ROOMA MYPOST P_A=AVG_PRES CMSEL,S,N_IMPD MYPOST P_B=AVG_PRES TL = 20*LOG10(P_A/P_B) /OUT *VWRITE,Freq,TL %12.5e,%12.5e *ENDDO /OUT,SCRATCH *DIM,Frq,CHAR,9,1 *DIM,TL1,CHAR,9,1 *DIM,TL2,CHAR,9,1 *DIM,Ratio,,9,1 Frq(1)='10','40','80','84','214','228','278','286','300' TL1(1)='29.000','0.000','22.000','20.000','51.500','8.000','34.000','24.000','28.500' TL2(1)='28.708','0.071','21.544','20.000','49.984','7.642','32.576','22.696','26.685' R1 = 28.7/28.5 R2 = 1.000 R3 = 21.5/21.5 R4 = 20.0/20.0 R5 = 50.0/51.5 R6 = 7.6/8.0 R7 = 32.6/33.0 R8 = 22.7/25.0 R9 = 26.7/29.0 *VFILL,Ratio(1,1),DATA,R1,R2,R3,R4,R5,R6,R7,R8,R9 /OUT,vm283,vrt /COM, -----------------VM283 RESULT COMPARISON--------------------- /COM /COM,| Freq (Hz) | Target | Mechanical APDL | Ratio | /COM, *VWRITE,Frq(1),TL1(1),TL2(1),RATIO(1,1) (3X,A8,' ',3X,A8,' ',3X,A8,' ',2X,F5.3,' ') /COM, /COM, --------------------------------------------------------------- /OUT, *list,vm283,vrt FINISH