Fan characteristic curve input to interface in cfx
 

I wanted to define performance curve at interface of 2 domains (imitating as if a fan operates suction@upstream & discharge@dwnstream). But if I define interface model to massflow and call the expression, following error i get,

"The parameter Mass flow rate' is single valued but depends on field valued-pressure"

I created expression fan curve(Pressure )

UF I created table for pressure vs massflow. Everything looked good, but solver is not accepting accepting massflow w.rt to pressure, when i call this expression in massflow interface model

I remember fluent can handle fan curve like a charm, piecewise linear method or polynomial eitherway.

I dont prefer using momentum source and calling this expression.
It would be helpful if someone can throw some light on using fan curve in massflow interface model.