Total mass flow/flux through a plane problem

nwalters · December 15, 2010, 21:51

I'm using fluent 12.1.4 and I'm having a problem getting the mass flow through a plane. In my model I have a plane which has mass flows through it in two directions. When I set up the surface integral on the plane it will give me the net mass flow as very close to zero because of continuity but I cannot determine the total flow or flux that is occuring. What is the best way to approach this problem.

A picture of the problem:

The plane i need for the mass flow (bulk) or flux is in red. (There is no pressure outlet at the bottom of the hopper so flow is forced to come back up through the plane).

skris2009 · December 18, 2010, 13:23

You can try this:
- Write out the velocity values on the plane (through export option in fluent)
- Open the file in Excel and perform a surface integral yourself. (separately for the positive and negative values)
- Use the average velocity values (both +ve and -ve) to compute two mass fluxes.

Or if you just want to know which direction flow is occurring, then just the net positive or negative velocity should suffice (if your flow is incompressible).

Hope this helps.

December 15, 2010, 21:51	Total mass flow/flux through a plane problem	#1
nwalters New Member Nick Walters Join Date: Dec 2010 Posts: 1 Rep Power: 0	I'm using fluent 12.1.4 and I'm having a problem getting the mass flow through a plane. In my model I have a plane which has mass flows through it in two directions. When I set up the surface integral on the plane it will give me the net mass flow as very close to zero because of continuity but I cannot determine the total flow or flux that is occuring. What is the best way to approach this problem. A picture of the problem: The plane i need for the mass flow (bulk) or flux is in red. (There is no pressure outlet at the bottom of the hopper so flow is forced to come back up through the plane).

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
DPM mass problem	Henrik Ström	FLUENT	9	May 20, 2016 12:00
how to get total mass of air through a surface	yubaibai88	FLUENT	0	June 2, 2010 09:14
concentration, total mass??	yee wan	FLUENT	0	February 24, 2003 22:34
Residual Problem -Mass Imbalance	Jie	FLUENT	0	February 19, 2002 11:49
total mass flux correction for compressible fluid?	Francesco Di Maio	Main CFD Forum	0	August 21, 2000 05:23

December 18, 2010, 13:23		#2
skris2009 New Member Sowmya K Join Date: Nov 2009 Posts: 22 Rep Power: 17	You can try this: - Write out the velocity values on the plane (through export option in fluent) - Open the file in Excel and perform a surface integral yourself. (separately for the positive and negative values) - Use the average velocity values (both +ve and -ve) to compute two mass fluxes. Or if you just want to know which direction flow is occurring, then just the net positive or negative velocity should suffice (if your flow is incompressible). Hope this helps.