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Old   September 29, 2016, 02:41
Default Please HELP!!! How to calculate average mass flow rate?
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Hi, I am a degree student. I was wondering how to calculate the average mass flow rate over the total time step at outlet.

Last edited by michellemay1993; September 29, 2016 at 09:02.
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Old   September 29, 2016, 12:02
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1.) Make An Expression for MyOutFlow = "massFlow()@outlet"
2.) Make a chart where you plot the transient results for this expression
3.) export it as .csv and average it in excel or some other program.

There may be another way using transient statistics, but I have not done it that way, so I can't tell you how.
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Old   September 30, 2016, 01:15
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Is this how it normally be calculated?
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Old   September 30, 2016, 11:54
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A modified version of Evcelica instructions:

If you are using CFD-Post :
1.) Make An Expression for MyOutFlow = "massFlow()@outlet"
2.) Make a chart where you plot the transient results for this expression
3.) In the Data Series tab, there is an info (i) icon (just below the (x) for delete). Click the info icon, and it will display the max/min/mean over the rang of the chart. There is just "time averaged value"

If you are using a recent version of ANSYS CFX, you can use the ANSYS CFX Solver Manager,

1.- Create a plot for the Boundary Flow for the continuity equation at the Outlet (effectively massFlow()@outlet).
2.- Create a Derived Variable for such plot (right click on the plot area), and look at the Derived Variables tab. Select the type of statistics you want to evaluate, say Time Average. Select the range of time for the averaging.
3 - Go to the Plot Variables tab, and activate on which individual plot you want the statistics to be computed; otherwise, it will compute on all the variables being plotted.

If you want for the quantities to be computed in the solver, and output to the ANSYS CFX Solver Manager,

1.- Create a monitor point
2.- Select Option = Expression, write the expression of interest
3.- Activate Transient Statistics for that expression and select the statistics of interest..

As you see, there are several ways to obtain what you need.

Hope the above helps,
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