Mass flow rate of each phase at outlet

Ahmed Saieed · March 31, 2016, 23:36

Hello and good day,

I am working on a piping network in which I have one inlet and two outlets. I am introducing air and water in to this system and my aim is to find the mass flow rate of each phase at both the outlets. As a beginner I am not about to figure out how I can do this. Currently my boundary condition at outlet is pressure outlet. can anyone help me with this.

Thank you

`e` · April 4, 2016, 17:28

Have a read of this thread on a UDF for measuring the mass flow rate at the outlet. As your problem is multiphase, then have a read of the "Special Considerations for Multiphase UDFs" in the UDF manual (use the phase domain index to distinguish between phases).

Ahmed Saieed · April 4, 2016, 22:22

thnx.... I am currently using monitors to generate graphs for mass flow rates at outlet and inlet.. the problem is that according to these graphs the mass flow rate at outlet is greater then inlet.... does it means the graphs generated by monitors arent accurate ?

`e` · April 4, 2016, 23:03

Is your simulation converged and is it steady or unsteady? For a converged steady state case, you should expect the inlet mass flow rates to equal the outlet mass flow rates.

Ahmed Saieed · April 4, 2016, 23:18

My flow regime at this moment is stratified. so its a steady state case.
No it havent converged. My flow rates of both the phases at outlet are kinda werid right from the start.. and thats wht worries me coz their sum should be equal to the inlet mass flow. this is wht conservation of mass states.

March 31, 2016, 23:36	Mass flow rate of each phase at outlet	#1
Ahmed Saieed New Member Join Date: Mar 2016 Posts: 4 Rep Power: 10	Hello and good day, I am working on a piping network in which I have one inlet and two outlets. I am introducing air and water in to this system and my aim is to find the mass flow rate of each phase at both the outlets. As a beginner I am not about to figure out how I can do this. Currently my boundary condition at outlet is pressure outlet. can anyone help me with this. Thank you

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April 4, 2016, 17:28		#2
`e` Senior Member Join Date: Mar 2015 Posts: 892 Rep Power: 18	Have a read of this thread on a UDF for measuring the mass flow rate at the outlet. As your problem is multiphase, then have a read of the "Special Considerations for Multiphase UDFs" in the UDF manual (use the phase domain index to distinguish between phases).

April 4, 2016, 22:22		#3
Ahmed Saieed New Member Join Date: Mar 2016 Posts: 4 Rep Power: 10	thnx.... I am currently using monitors to generate graphs for mass flow rates at outlet and inlet.. the problem is that according to these graphs the mass flow rate at outlet is greater then inlet.... does it means the graphs generated by monitors arent accurate ?

April 4, 2016, 23:03		#4
`e` Senior Member Join Date: Mar 2015 Posts: 892 Rep Power: 18	Is your simulation converged and is it steady or unsteady? For a converged steady state case, you should expect the inlet mass flow rates to equal the outlet mass flow rates.

April 4, 2016, 23:18		#5
Ahmed Saieed New Member Join Date: Mar 2016 Posts: 4 Rep Power: 10	My flow regime at this moment is stratified. so its a steady state case. No it havent converged. My flow rates of both the phases at outlet are kinda werid right from the start.. and thats wht worries me coz their sum should be equal to the inlet mass flow. this is wht conservation of mass states.