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Pressure coefficients

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Robert000

Structural
Oct 23, 2005
45
Hi all,
I would like to determine pressure coefficients on a building with flat roof and compare them with values in Eurocode. The standard establish on the windward side of the building pressure +0,77 and on the leeward side suction with value -0,45.
But the calculated results are much greater that in EC.
What should be the problem??

Thanks a lot,
Robert

!/FILNAME,RO_triangular,0
!/CWD,'E:\ANSYS\RO_triangular mesh'
!/TITLE,Rectangular object-triangular meshing
aa=5
bb=3
cc=5
/prep7
k,1,0,0,0 !node definitions
k,2,0,4*bb,0
k,3,0,0,3*cc
k,4,0,4*bb,3*cc
k,5,6*aa,0,0
k,6,6*aa,4*bb,0
k,7,6*aa,0,3*cc
k,8,6*aa,4*bb,3*cc
k,9,-3*aa,0,-6*cc
k,10,-3*aa,12*bb,-6*cc
k,11,-3*aa,0,6*cc
k,12,-3*aa,12*bb,6*cc
k,13,9*aa,0,-6*cc
k,14,9*aa,12*bb,-6*cc
k,15,9*aa,0,6*cc
k,16,9*aa,12*bb,6*cc
v,9,10,12,11,13,14,16,15 !volume definitions
v,1,2,4,3,5,6,8,7
VSBV, 1, 2 !substracting volumes
ET,1,FLUID142 !element type
MPTEMP,,,,,,,, !material properties
MPTEMP,1,0
MPDATA,DENS,1,,1.25
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,VISC,1,,1.79e-005
LESIZE,ALL, , ,15, ,1, , ,1, !element size selection
MSHKEY,0 !mesh generation
MSHAPE,1,3d
CM,_Y,VOLU
VSEL, , , , 3
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
!*
VMESH,_Y1
!*
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
da,all,vx,0,1 !boundary conditions on areas
da,all,vy,0,1
da,all,vz,0,1
dadele,2,all
da,1,vz,-26,1
da,3,vz,-26,1
da,4,vz,-26,1
da,6,vz,-26,1
da,2,pres,0,1
FLDATA1,SOLU,FLOW,1
FLDATA1,SOLU,TURB,1
FLDATA1,SOLU,RDSF,1
FLDATA2,ITER,EXEC,50,
FLDATA5,OUTP,RESI,1
FLDATA7,PROT,DENS,AIR-SI
FLDATA8,NOMI,DENS,-1
FLDATA7,PROT,VISC,AIR-SI
FLDATA8,NOMI,VISC,-1
FLDATA24,TURB,MODL,1
FLDATA24,TURB,CMU,0.09,
FLDATA24,TURB,C1,1.44,
FLDATA24,TURB,C2,1.92,
FLDATA24,TURB,SCTK,1,
FLDATA24,TURB,SCTD,1.3,

FLDATA24,TURB,ININ,0.01,
FLDATA24,TURB,INSF,0.01,
FLDATA24,TURB,RATI,1000000, !higher turbulence value
FLDATA24,TURB,SCTT,0.85,
FLDATA24,TURB,SCTM,1,

FLDATA34,MIR,MOME,0.2, !matrix has a negative diagonal problem solution
FLDATA34,MIR,TEMP,0.2,
FLDATA34,MIR,TURB,0.2,

FINISH
/SOL
SOLVE

FLDATA24,TURB,ININ,0.01,
FLDATA24,TURB,INSF,0.01,
FLDATA24,TURB,RATI,1000, !default turbulence value
FLDATA24,TURB,SCTT,0.85,
FLDATA24,TURB,SCTM,1,
!*
/COM,,Steady State Analysis,0
FLDATA2,ITER,EXEC,100, !100 iterations
FLDATA2,ITER,OVER,0,
FLDATA2,ITER,APPE,0,
FLDATA3,TERM,VX,0.01,
FLDATA3,TERM,VY,0.01,
FLDATA3,TERM,VZ,0.01,
FLDATA3,TERM,PRES,1e-008,
FLDATA3,TERM,TEMP,1e-008,
FLDATA3,TERM,ENKE,0.01,
FLDATA3,TERM,ENDS,0.01,
FLDATA5,OUTP,SUMF,10,
!*
FLDATA5,OUTP,PTOT,1
FLDATA5,OUTP,TTOT,0
FLDATA5,OUTP,HFLU,0
FLDATA5,OUTP,HFLM,0
FLDATA5,OUTP,STRM,1
FLDATA5,OUTP,PCOE,1 !pressure coefficient output
FLDATA5,OUTP,MACH,0
FLDATA5,OUTP,YPLU,0
FLDATA5,OUTP,TAUW,0
FLDATA5,OUTP,RDFL,0
SOLVE
FINISH
/POST1
SET,LAST
wpstyle,15,5,0,60,0.001,0,1,,5
wpro,,,-90.000000
wpof,,,-15.000000
WPSTYLE,,,,,,,,0
/EFACET,1
PLNSOL, PCOE,, 0
/GRAPHICS,POWER
/TYPE,1,8
/CPLANE,1
/SHADE,1,1
/HBC,1,0
/REPLOT


 
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