in the "boundaries" tab, it seems that the boundary condition mark(such as "S" for symmetry, "W" for wall "WL" for wave etc.) will only show on side which begin from 0, for example, if the mesh block in X direction is from 0 to 10, the BC mark is right on the side which x min=0,and x max=10. But if the mesh block in X dir is from 10 to 20,the BC mark is still on the side whick X min=0,X max=10,so the BC mark now isn't on the mesh boundary, how can I do to modify these?

It sounds like a display problem only. Look at the prepin file and check bcdata there (under file - edit simulation). Perhaps closing the GUI and reopening it or switching tabs and going back will fix it.

The following is the input file, I try to edit it and reopen, but seems no use...

Title This is a sample input file

&xput

remark='units are ...',

twfin=5.,

itb=1,

ifin=2, gz=0.,

iedt=2, pltafrc=0.01,

ivort=1,

gy=10., /

&limits /

&props

rhof=1000.,

rhofs=917., thexf1=0.00018, cv1=4182., cvs1=2100.,

pofl1=0., thc1=0.597, thcs1=2.215, clht1=3.35e+05,

ts1=273., tl1=273., tniyam=-1., tsdrg=1.,

mu1=0.001, muc00=0., muc0=1., muc1=0.,

muc2=0., muc3=0., mutmp1=0., mutmp2=0.,

mutmp3=1., muthk=0., muthn0=0., muthn1=0.,

cangle=90., sigma=0.073, csigma=0., rf2=2.87e+06,

tmelt=0., teut=0., ceut=0., cexf1=0.,

cstar=0., dratio=0., pcoef=0., fluid1='Water at 20 C',

units='SI', /

&scalar /

&bcdata

ubct(1,2)=-2.,

wbk=6,

vbct(1,4)=-2., /

&mesh

nxcelt=40, px(1)=700., px(2)=710.,

nycelt=20, py(1)=695., py(2)=705.,

nzcelt=8, pz(1)=0.0, pz(2)=4.,

/

&obs /

&fl /

&bf /

&temp /

&motn /

&grafic

anmtyp(1)='f',

anmtyp(2)='vel', anmtyp(3)='part',

anmtyp(4)='vort', /

&renderspace

ifrs=0,

ifcomp=0,

ifcompf=1,

rsxmin=700, rsxmax=704, rsymin=690, rsymax=700,

rszmin=0, rszmax=4, rscsize=1, / &HEADER

PROJECT='SHBn', /

&parts /

Documentation: general comments, background, expectations, etc.

&bcdata ubct(1,2)=-2., wbk=6, vbct(1,4)=-2., /

This defines the back boundary, Y max, as a velocity boundary. Perhaps you do not have proper write permissions for the prepin file. Close Flow-3D gui and try editing the prepin file with a text editor like notepad, and insert wl=6, to make X min a velocity boundary. If you cannot save the change, then you probably do not have write privileges and should contact your computer support department. You could also try editing the file in a different directory. Just a guess.

&bcdata ubct(1,2)=-2., wbk=6,wl=6, vbct(1,4)=-2., /

May I send the input file to you ?

ShFlow, I brought in and then typed in the same mesh information you are using, and duplicated the problem. It appears to only be a display/GUI problem. If the text in the editor is correct, then the simulation should run fine.

&bcdata

wr=6, wbk=6, ubct(1,2)=-2, vbct(1,4)=-2, /

&mesh

nxcelt=40, px(1)=700.,px(2)=710.,

nycelt=20, py(1)=695., py(2)=705.,

nzcelt=8, pz(1)=0.0, pz(2)=4., /

Jim