[luke84]

Is it somehow possible to do as the title of the thread reads, and define a multi-variable argument, locator based function?

A little more info:
My simulation involves a jet of fluid, pointing in the X positive direction. Using CFX_PRE V13
I want to find the spread angle of the jet, i.e angle between the majority of the vectors and the vector (1,0,0) (x-positive direction)

So I start with the equation for an angle between 2 vectors:


where u is the vector (1,0,0) and v is the velocity vector at the mesh locator OUTLET.

since the u vector is fully dercribed in only one direction and is the unity vector, the formula can be simplified to:

*Note; here alpha is actually defining the half spread angle.

This could be set as an expression as follows:
alpha=acos(Velocity u*1 [m s^-1]/(Velocity u^2+Velocity v^2+Velocity w^2))
*Note I multiply with 1 [m s^-1] to keep dimensions consistent.

Now if I set a monitor point as:
massFlowAve(alpha)@OUTLET
I get a error message along the lines of:

"The function 'massFlowAve' referenced in parameter 'Expression Value' in object '/FLOW:Flow Analysis 1/OUTPUT CONTROL/MONITOR OBJECTS/MONITOR POINT:ALPHA_MONITOR' has an invalid argument, 'alpha'. Only arguments that consist of a single recognised variable name are supported by the solver."

As far as I can tell, the problem above basically means that I can only define one variable (e.g Velocity u) and not 2 or 3 variables in the locator based function; massFlowAve().
Note that the exact same method DOES work for me in CFX-POST. Thas is defining the same expression, and using the function calculator.
So does anyone have an idea how to circumvent this problem in CFX-PRE??

Thanks in advance!