Numerical Beach

Omran · March 10, 2015, 10:05

Hi,

"The waves generated by the flapper will reflect back into the domain from the outlet. A numerical beach that dampens or removes waves once they have passed the region of interest should be added if this reflection is not desired."

How can I create a numerical beach in cfx?

Thansks.

ghorrocks · March 10, 2015, 17:52

It can either be a real beach, where you gradually make the water shallower so the waves break and dissipate; or a numerical beach where you dissipate the energy numerically - transitioning to a very coarse mesh near the outlet can do this nicely. You can also use source terms to damp the flow, that can work too.

Omran · March 10, 2015, 18:29

Thanks ghorrocks

"You can also use source terms to damp the flow, that can work too."

How can I do it?

Thanks.

ghorrocks · March 11, 2015, 00:45

By using resistance terms, for example the linear or quadratic terms used in porous flow models. You can either use a porous model to do this or use a source term.

Omran · March 15, 2015, 13:39

Thanks ghorrocks
Coarse mesh did't work and then I tried porous flow models but I don't how I have to do it.

March 10, 2015, 10:05	Numerical Beach	#1
Omran New Member Omran Join Date: Feb 2015 Posts: 16 Rep Power: 11	Hi, "The waves generated by the flapper will reflect back into the domain from the outlet. A numerical beach that dampens or removes waves once they have passed the region of interest should be added if this reflection is not desired." How can I create a numerical beach in cfx? Thansks.

March 10, 2015, 17:52		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	It can either be a real beach, where you gradually make the water shallower so the waves break and dissipate; or a numerical beach where you dissipate the energy numerically - transitioning to a very coarse mesh near the outlet can do this nicely. You can also use source terms to damp the flow, that can work too. Omran likes this.

March 11, 2015, 00:45		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	By using resistance terms, for example the linear or quadratic terms used in porous flow models. You can either use a porous model to do this or use a source term. fumiya and Omran like this.

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March 10, 2015, 18:29		#3
Omran New Member Omran Join Date: Feb 2015 Posts: 16 Rep Power: 11	Thanks ghorrocks "You can also use source terms to damp the flow, that can work too." How can I do it? Thanks.

March 15, 2015, 13:39		#5
Omran New Member Omran Join Date: Feb 2015 Posts: 16 Rep Power: 11	Thanks ghorrocks Coarse mesh did't work and then I tried porous flow models but I don't how I have to do it.