on cavity driven flow

September 18, 2001, 22:13

hi there,

i have coded a progrom to simulate the flow in a rectangular cavity. the problem is formulated in vorticity-stream function. i employed the method of false transient and solutions were obtained for various Re numbers. to my surprise, for Re>100(upwind scheme is used for Re>100), i obtained two different solutions for each Re by using different time step. i checked for the continuity equation and it is satisfied for both solutions.

can this be true or is it a kind of bifurcations? please advise. thanks in advance.

regards, yfyap

September 19, 2001, 06:24

One of possibility is upwind method is explicit scheme, so it has CFL condition which is restricted by Re number.

September 19, 2001, 08:12

Sorry, there is only one solution for each Re nunber. Was your system truly converged in both cases?

September 19, 2001, 18:16

(1). Check out your code on a simpler check case first. (2). What is your "false transient" method?

September 18, 2001, 22:13	on cavity driven flow	#1
yfyap Guest Posts: n/a	hi there, i have coded a progrom to simulate the flow in a rectangular cavity. the problem is formulated in vorticity-stream function. i employed the method of false transient and solutions were obtained for various Re numbers. to my surprise, for Re>100(upwind scheme is used for Re>100), i obtained two different solutions for each Re by using different time step. i checked for the continuity equation and it is satisfied for both solutions. can this be true or is it a kind of bifurcations? please advise. thanks in advance. regards, yfyap

September 19, 2001, 06:24	Re: on cavity driven flow	#2
Junseok Kim Guest Posts: n/a	One of possibility is upwind method is explicit scheme, so it has CFL condition which is restricted by Re number.

September 19, 2001, 08:12	Re: on cavity driven flow	#3
Sebastien Perron Guest Posts: n/a	Sorry, there is only one solution for each Re nunber. Was your system truly converged in both cases?

September 19, 2001, 18:16	Re: on cavity driven flow	#4
John C. Chien Guest Posts: n/a	(1). Check out your code on a simpler check case first. (2). What is your "false transient" method?

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