hi!! I'm working on a fan optimisation with the cfx571 cfd software. The fan i am studing is a part of an machine. So to optimize the fan and so the airflow throught the machine, i have to consider the pressure looses. How can i simply represent the pressure looses without represent all the geometry of the machine?

Hi,

Use a momentum source. Look under general sources in the documentation. Create a CEL function which calculates the pressure increase across the fan, and set the flow rate with the momentum source according to the fan curve. You can use a interpolation function to have the entire fan curve if you like.

Glenn Horrocks

thank u Glenn!! I did not be clear to explain my issue. I try to explain the problem again

hi!! I'm working on a fan optimisation with the cfx571 cfd software. The fan i am studing is a part of an machine. So to optimize the fan and so the airflow throught the machine, i have to consider the pressure looses. How can i simply represent the pressure looses without represent all the geometry of the machine?

-----------------------! machine with pressure ! looses due to the ! complexity of the ! connected to geometry. !

!--------------> the fan

!

!

!

! -----------------------!

I would want to create thhe fan geometry into a pipe and i would want to simulate the pressure looses (that exist in the machine) at the beginning of the pipe.

How can i represent these pressures looses? I know that i could impose a pressure in the inlet of the pipe. Is it the best solution?

Hi,

You can use a momentum source to model the pressure loss in the machine then. You might want to use a flow loss source (pressure loss proportional to velocity squared) in this case - as long as the Reynolds number is high enough.

Glenn Horrocks