|
[Sponsors] |
March 30, 2013, 06:56 |
l Inf in wave transmissive bc
|
#1 |
Member
VS
Join Date: Nov 2012
Posts: 86
Rep Power: 13 |
Hey guys,
does anybody know how l inf works in wave transmissive boundary condition? In Wiki it says it's a measure of how far the farfield should be, but i don't know which exact value to give.How we difine it on each problem? Thanks |
|
March 30, 2013, 07:28 |
|
#2 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
it indicates how much of wave is reflected and how much is transferred out of the domain.you could try some values.it depends of the dimensions of your problem.if its too low it will be like totalPressure or fixedValue.set it .1 or 1 to test which is more appropriate.
|
|
April 1, 2013, 04:37 |
|
#3 |
Member
VS
Join Date: Nov 2012
Posts: 86
Rep Power: 13 |
Hey,
thanks for the reply. Is there anyway to precisely set the value? I mean, why to set 0.1 and not 0.3 or something else? Also, does it corresponds on a characteristic length, let's say, a diameter or a mean chord? Regards |
|
April 1, 2013, 05:48 |
|
#4 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
i think it is more a triel and error work if someone correct me.whats your problem?if you want to the waves reach the patches transfer very close to completely (maybe some numerical waves reflect) choose a large number.there are some papers i have seen about this bc in the net.
Are you certain to use this bc?why? |
|
April 1, 2013, 06:02 |
|
#5 |
Member
VS
Join Date: Nov 2012
Posts: 86
Rep Power: 13 |
Well, i have compressible flow around a sphere in a spherical far field. I tried inletOutlet/outletInlet BCs for U,T,p but i didn't get the correct solution. I read somewhere that wavetransimissive bc is better for compressible unsteady problems. I'm trying to set the correct l inf in order to have an accurate solution and no reflections.
|
|
April 1, 2013, 09:40 |
|
#6 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
did you reach the appropriate value?let me know.also see tutorials.
|
|
April 8, 2013, 15:48 |
|
#7 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
did you succeed?how?with spherical or cylindrical farfield?
|
|
April 9, 2013, 04:01 |
|
#8 |
Member
VS
Join Date: Nov 2012
Posts: 86
Rep Power: 13 |
No success yet. If waveTransmissive is p outlet/Inlet for compressible flow, then it should work. I tried also zeroGradient for temperature, but it wasn't helpful.My flow doesn't seem to spread behind the sphere, it seems like we have reflections from the outer boundary.
|
|
January 9, 2014, 21:07 |
test
|
#9 | |
New Member
Oscar Ochoa
Join Date: Nov 2013
Posts: 4
Rep Power: 12 |
Quote:
I did my own tests to understand the behaviour of lInf in the waveTransmissive BC. I took the wedge example in the rhoCentralFoam solver and used Ma=2.0. Keeping everything fixed I only modified the value of lInf (the results can be seen in the attached images. The image file name is the value given i.e. plInf10e-2 means lInf=10e-2). The way I understand for values lInf>1 the far-field condition is outside of the domain, for values lInf>1 the far-field condition is inside the domain. I did tests whit values grater than 1 (lInf=10e2 and lInf=10e3), but the results were the same that lInf=10e0. Regards |
||
January 10, 2014, 03:13 |
|
#10 |
Member
VS
Join Date: Nov 2012
Posts: 86
Rep Power: 13 |
Oscar,
I agree with your results. As they show, for different lInf<1 we have a different problem each time. Truly representative work. Regards |
|
January 10, 2014, 05:19 |
|
#11 | |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
Quote:
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
||
Tags |
wavetransmissive |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Pressure for wave height in an Water Wave Tank | Cluain | CFX | 8 | December 6, 2021 03:58 |
Linear wave force on a cylinder | Pumbam | CFX | 1 | July 16, 2017 02:01 |
Wave Transmissive and Advective | sahm | OpenFOAM Programming & Development | 8 | November 15, 2015 05:15 |
WAVE TANK star-ccm+ . wave height dampens. WHY? | muhsin | STAR-CCM+ | 3 | October 9, 2012 13:24 |
Scaling up a wave energy converter - free surface flow | mark_l | CFX | 3 | February 17, 2010 16:57 |