Learning Forum

[Dato]

Hi all,

I want to define a Expression in Fluent which calculate the total pressure on the inlet. But a error occurred as shown below. 

When I change the MassAve to AreaAve, the expression is valid. Does it means that the MassAve is not availble in the expression definition? Because I can get the Mass-weighted average Total Pressure on the "inlet" using the "Surface Integrals" panel. 

 

Anyone have encountered similar problem? Any suggestions is appreciated.

 

 

[Rob]

Have a look in here https://ansyshelp.ansys.com/public/account/Secured?returnurl=/Views/Secured/corp/v261/en/flu_ug/flu_ug_expressions_intro.html%23flu_ug_expressions_functions  Section 5.1.1.3 just below the tables. 

[Rob]

And also look at MassFlowAve(...)

[Dato]

Thanks Rob, I have checked the section 5.1.1.3. The document shows only shows the usage of the MassAve and it is the same with the MassFlowAve. However, the illustration of definition is not given in the user guide. I know that I should use the MassFlowAve. 

I'm wonder why  the location of my "inlet " is invalid. I have created interior surface rather than boundary surface to specify the location in the MassAve. But invalid is also shown.  Can you give out the mathematical definition of the MassAve and some instruction on the using of the MassAve. 

Best reageds

 

 

[Dato]

And I also wonder if the function of the notification of new reponse by e-mail is cancelled in the new Ansys Learning Forum. 

[Rob]

You can use the MassAve in an expression, just not  report definition. I don't know why, but it's possible there's a block to prevent a MassAve/MassFlowAve being added to a wall.

I'll flag to be checked, but won't be able to comment on that part further as it's Ansys internal.