Learning Forum

[soloviev]

Hello,

I am trying to create a report for momentum at a surface in my model. I created report definitions for mass and velocity and am now trying to use the monitor expression to do mass*velocity for momentum.

When I do this I get the error that the expression is not single valued.

Thanks,

Alex

[YasserSelima]

This expression calculates the values at all cells. To have it on a surface ... select reduction ... average ... n

[soloviev]

Thank you! I did this and the attached expression came up (sorry I have not used expressions before). Where it says location I tried to type a location saved in Fluent but it did not come up. I'm also not sure where to add in the mass* velocity into what is now there.n

[YasserSelima]

Average(your_expression, ['surface_name'],Weight='Mass')n

[soloviev]

Thank you! I see why my location is invalid. It is a plane I created at a specified height. Is this possible or do I have to use a location at a boundary?n

[YasserSelima]

I never did this before, so I don't know. But if your location is not available when you select the location button, probably it is not possible.nBut you can still do it with the report definition. Define a custom field function ... (mass*velocity) and get its mass average on your surface through report definitionn

[soloviev]

Thank you! I didn't know I could create custom field variables.n

[YasserSelima]

You are welcome!n