Flow-split outlet

jano5889 · June 9, 2015, 09:39

Hi,
I have three horizontal tubes forming a T, with three different diameters. I have velocity inlet but I don't know the outlet's pressures. What happens if I set the outlets as Flow-Split Outlet, setting both split ratio to 1? In what way does the fluid split itself in this case?
Thank you very much

jano5889 · June 16, 2015, 05:36

Please answer me if you can!!! It is very important

me3840 · June 29, 2015, 23:03

I don't think you can do this, the flow split outlets are formulated to conserve mass. The code will probably not allow you to specify them both as 1.

kirrer · July 9, 2015, 11:42

Maybe bringing up an old thread, but I would not use flow split outlets. I think what you mean, is that for each outlet, the flow should be 50% of the inlet flow. In this case, set one outlet to a mass flow inlet, calculate 50% of the mass flow, and apply the mass flow as a negative value (ie, 1 kg/s in means -0.5 kg/s on that mass flow inlet, so it is effectively an outlet).

Then, set the other outlet to Pressure out, and through mass conservation, you will automatically get 50% of the flow at that outlet as well.

jano5889 · July 9, 2015, 12:52

Thank you very much!!!

ggulgulia · July 16, 2015, 08:39

Hi Jano

If you are looking to get a specified fraction of mass flowing through each tube, then flow split outlet is the best option, the sum of fraction of mass flowing through each outlet being 1.0

You must also specify the guage pressure by opening the solver manager and applying target pressure at specfied boundary (here you have to input the coordinates of any one point lying on the boundary)

June 9, 2015, 09:39	Flow-split outlet	#1
jano5889 New Member Jacopo Join Date: Apr 2015 Posts: 15 Rep Power: 11	Hi, I have three horizontal tubes forming a T, with three different diameters. I have velocity inlet but I don't know the outlet's pressures. What happens if I set the outlets as Flow-Split Outlet, setting both split ratio to 1? In what way does the fluid split itself in this case? Thank you very much

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June 16, 2015, 05:36		#2
jano5889 New Member Jacopo Join Date: Apr 2015 Posts: 15 Rep Power: 11	Please answer me if you can!!! It is very important

June 29, 2015, 23:03		#3
me3840 Senior Member Join Date: Nov 2010 Location: USA Posts: 1,232 Rep Power: 24	I don't think you can do this, the flow split outlets are formulated to conserve mass. The code will probably not allow you to specify them both as 1.

July 9, 2015, 11:42		#4
kirrer New Member Kevin Join Date: Oct 2012 Posts: 29 Rep Power: 13	Maybe bringing up an old thread, but I would not use flow split outlets. I think what you mean, is that for each outlet, the flow should be 50% of the inlet flow. In this case, set one outlet to a mass flow inlet, calculate 50% of the mass flow, and apply the mass flow as a negative value (ie, 1 kg/s in means -0.5 kg/s on that mass flow inlet, so it is effectively an outlet). Then, set the other outlet to Pressure out, and through mass conservation, you will automatically get 50% of the flow at that outlet as well.

July 9, 2015, 12:52		#5
jano5889 New Member Jacopo Join Date: Apr 2015 Posts: 15 Rep Power: 11	Thank you very much!!!

July 16, 2015, 08:39		#6
ggulgulia Senior Member Gajendra Gulgulia Join Date: Apr 2013 Location: Munich Posts: 144 Rep Power: 13	Hi Jano If you are looking to get a specified fraction of mass flowing through each tube, then flow split outlet is the best option, the sum of fraction of mass flowing through each outlet being 1.0 You must also specify the guage pressure by opening the solver manager and applying target pressure at specfied boundary (here you have to input the coordinates of any one point lying on the boundary)