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Re: About ConvectionBC

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› Forums › OpenLB › General Topics › About ConvectionBC › Re: About ConvectionBC

July 11, 2017 at 5:19 pm #2652
steed188
Participant

Dear mathias,
Sorry for so late.
Here’s a picture that I tried the convection and pressure boundary.

[img]http://photry-production-virginia.s3.amazonaws.com/1288/1538/63365/large.jpeg?AWSAccessKeyId=AKIAIFWXMUQTJZO2WGXA&Expires=1499790408&Signature=4MGbkW0NFciumBPq2%2B8lyS5QQ90%3D[/img]
[img]http://photry-production-virginia.s3.amazonaws.com/1288/1538/63366/large.jpeg?AWSAccessKeyId=AKIAIFWXMUQTJZO2WGXA&Expires=1499790409&Signature=SASQFxbQCNSruGTwEErgo9usEJA%3D[/img]
You see that when I used pressure boundary, there was velocity there that the fluid went out.
While I used convection boundary, there is no velocity to go out . So that the fluid always moved in the filed and no outlet.

That’s weird because I thought that the convection boundary should have same effect with pressure boundary in my case.

By the way, I’m working on some High Reynolds fluid that the kinetic viscosity gets 10e5. Under this kind of kinetic viscosity, the simulation is always diverged if using pressure bc. But the convection bc seems dose not work as I showed upper. Do you have some idea that how can I work with pressure bc under so high reynolds fluid?

best
steed188