variable composition mixture

ranjith · October 14, 2010, 02:18

Hi,
I am simulating mixing of two fluids of different viscosity and different density. For this I have defined a variable composition mixture. The domain is initially filled with fluid A( by defining mass fraction of A as 1 in the mixture initially). The fluid entering the domain is entirely composed of fluid B( by defining mass fraction of B as 1 at the inlet). Bouyancy is switched on to capture the hydrostatic effects. A transient simulation was done with total time equal to the time taken to travese the domain(at a fixed flow rate)
The problem is that there is no flow at all. Instead a small portion of the fluid at the outlet comes in. I dont know why this happens. Would greatly appreciate any help

Ranjith

michael_owen · October 14, 2010, 22:10

Did you initialize the hydrostatic pressure?

ranjith · October 15, 2010, 00:30

No, where can I do it

michael_owen · October 15, 2010, 10:50

Domain Initialization. Read the tutorials on free surface flows to see how to initialize a hydrostatic pressure.

October 14, 2010, 02:18	variable composition mixture	#1
ranjith New Member ranjith Join Date: Dec 2009 Posts: 19 Rep Power: 16	Hi, I am simulating mixing of two fluids of different viscosity and different density. For this I have defined a variable composition mixture. The domain is initially filled with fluid A( by defining mass fraction of A as 1 in the mixture initially). The fluid entering the domain is entirely composed of fluid B( by defining mass fraction of B as 1 at the inlet). Bouyancy is switched on to capture the hydrostatic effects. A transient simulation was done with total time equal to the time taken to travese the domain(at a fixed flow rate) The problem is that there is no flow at all. Instead a small portion of the fluid at the outlet comes in. I dont know why this happens. Would greatly appreciate any help Ranjith

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
variable composition mixture properties	Neser25	CFX	6	August 17, 2020 15:19
Variable Composition Mixture vs. Fluid Pair	Abby	CFX	0	February 18, 2009 12:00
error in COMSOL:'ERROR:6164 Duplicate Variable'	bhushas	COMSOL	1	May 30, 2008 05:35
Variable composition mixture .vs. reacting mixture	Ting Wen	CFX	0	January 7, 2008 07:04
Replace periodic by inlet-outlet pair	lego	CFX	3	November 5, 2002 21:09

October 14, 2010, 22:10		#2
michael_owen Senior Member Michael P. Owen Join Date: Mar 2009 Posts: 196 Rep Power: 17	Did you initialize the hydrostatic pressure?

October 15, 2010, 00:30		#3
ranjith New Member ranjith Join Date: Dec 2009 Posts: 19 Rep Power: 16	No, where can I do it

October 15, 2010, 10:50		#4
michael_owen Senior Member Michael P. Owen Join Date: Mar 2009 Posts: 196 Rep Power: 17	Domain Initialization. Read the tutorials on free surface flows to see how to initialize a hydrostatic pressure.