[pyxbird]

Dear all,
Hi, I am simulating flow in a flume, the inlet boundary is velocity boundary, however every time I begin the simulation, the water level will increase and extend to the outlet boundary and never descend. For example, the fluid elevation I define at the inlet and outlet boundary is 50cm, but after the flow becoming steady the water level keeps 55cm and never change. How can I solve this problem?
1.At the outlet boundary, I have tried continuative, pressure and outflow boundary.
2.I have tried to increase the velocity slowly at the inlet boundary but it doesn't work.
3.I have put an obstacle at the top of the flume to avoid water rising but the simulation will exit anormally.
So who can figure out why?

[gdtiaozi]

Model Setup->General->Interface tracking->Free surface or sharp interface

Model Setup->General->Number of fluids->One fluid

Model Setup->Meshing & Geometry->Initial->Void initial state->Pressure:101325Pa

[pyxbird]

Originally Posted by gdtiaozi

Model Setup->General->Interface tracking->Free surface or sharp interface

Model Setup->General->Number of fluids->One fluid

Model Setup->Meshing & Geometry->Initial->Void initial state->Pressure:101325Pa

Thank you, maybe I should give the pressure of air, I will try it soon.

[pyxbird]

Originally Posted by gdtiaozi

Model Setup->General->Interface tracking->Free surface or sharp interface

Model Setup->General->Number of fluids->One fluid

Model Setup->Meshing & Geometry->Initial->Void initial state->Pressure:101325Pa

It doesn't work, the level of the water still rises and doesn't dscend.
I will show two pitures below.

[Jing_min]

Originally Posted by pyxbird

Dear all,
Hi, I am simulating flow in a flume, the inlet boundary is velocity boundary, however every time I begin the simulation, the water level will increase and extend to the outlet boundary and never descend. For example, the fluid elevation I define at the inlet and outlet boundary is 50cm, but after the flow becoming steady the water level keeps 55cm and never change. How can I solve this problem?
1.At the outlet boundary, I have tried continuative, pressure and outflow boundary.
2.I have tried to increase the velocity slowly at the inlet boundary but it doesn't work.
3.I have put an obstacle at the top of the flume to avoid water rising but the simulation will exit anormally.
So who can figure out why?

Hi
Please send me the file : "prepin"

[pyxbird]

Originally Posted by Jing_min

Hi
Please send me the file : "prepin"

Title
This is a sample input file
$xput
remark='!! Remarks beginning with "!! " are automatically added and removed by FLOW-3D.',
remark='!! Do not begin any user added remarks with with "!! ". They will be removed',
twfin=250,
itb=1,
ifin=4,
ifvisc=1,
ifvis=4,
ifdynconv=1,
gz=-980,
ipdis=1,
idpth=1,
ifmu=1,
tpltd(1)=0.5,
$end
$limits
$end
$props
units='cgs',
tunits='c',
mu1=0.01,
fluid1='Water at 293 K',
thexf1=0.00018,
cv1=41820000,
tstar=100,
tl1=-0.149999999999977,
ts1=-0.149999999999977,
clht1=3350000000,
cvs1=21000000,
thcs1=221500,
rhofs=0.917,
teut=-273.15,
tmelt=-273.15,
ceut=0,
pcoef=0,
rhof=1.0,
sigma=73,
thc1=59700,
$end
$scalar
$end
&PCAP
/
&BCDATA
remark='!! Boundary condition X Min',
ibct(1)=6,
ubct(1, 1)=44.1,
fbct(1, 1)=1,
flhtbct(1, 1)=50,
remark='!! Boundary condition X Max',
ibct(2)=8,
flhtbct(1, 2)=50,
remark='!! Boundary condition Z Min',
ibct(5)=2,
/
&MESH
ntotal=1000,
nxcelt=2500,
px(1)=0,
px(2)=5000,
nycelt=1,
py(1)=0,
py(2)=1,
nzcelt=70,
pz(1)=0,
pz(2)=70,
/
$obs
remark='!! Component common parameters',
avrck=-3.1,
$end
$fl
nfls=1,
remark='!! Fluid Region 1',
fluidRegionName(1)='Water at 293 K',
fzh(1)=50,
pvoid=1.01325e+05,
iflinittyp=0,
$end
$bf
$end
$temp
$end
$motn
$end
$grafic
anmtyp(1)='dpth',
anmtyp(2)='f',
anmtyp(3)='vel',
$end
&HEADER
project='pre out',
/
$parts
$end
Documentation: general comments, background, expectations, etc.

#start tables:
#fluid1:
#blkmodts
#end blkmodts
#cv1
#end cv1
#cvnc
#end cvnc
#elastmodts
#end elastmodts
#emod1
#end emod1
#fs
#end fs
#mu1sr
#end mu1sr
#mu1t
#end mu1t
#poissonrts
#end poissonrts
#rhof
#end rhof
#shrmodts
#end shrmodts
#sigma
#end sigma
#thc1
#end thc1
#yield1
#end yield1
#end fluid1
#fluid2:
#cv2
#end cv2
#emod2
#end emod2
#mu2sr
#end mu2sr
#mu2t
#end mu2t
#rhof2
#end rhof2
#thc2
#end thc2
#yield2
#end yield2
#end fluid2
#end start tables

[pyxbird]

Originally Posted by Jing_min

Hi
Please send me the file : "prepin"

sorry, some errors emerge when I am uploading the prepin file, can you see it in my reply?

[flow_CH]

Originally Posted by pyxbird

sorry, some errors emerge when I am uploading the prepin file, can you see it in my reply?

send me zip file of prepin.