Learning Forum

[mxmgr]

Hi,

I'm looking for a solution to specify an unit parameter, when I'm working with Fluent from batch in a journal file .

First, I define the parameters process:

def par ip adv ui us "ux" 5.5

def para enable yes

Here, we've got an input parameter "ux", which describes a velocity. Thus, we can see in "Parameters & Customization" --> "Parameters" --> "Input Parameters", the parameter "ux" which takes value (5.5).

It's important to observe that no unit is specified in this parameter, which is a problem for the next command. When I want to apply this parameter in a boundary condition, with these commands :

def bc zt label-1 velocity-inlet

def velocity-inlet label-1 "ux"

thus, we've got these lines on Fluent's console :

Velocity Specification Method: Magnitude and Direction [no] yes

Reference Frame: Absolute [yes] yes

Use Input Parameter for Velocity Magnitude? [no] yes

Name of parameter ["parameter-2"] "ux"

ux value (in [m/s]) [0] 5.5

and this error appears :

Error: 'ux'is predefined expression. Please change name.

Error Object: #f

Fluent commands doesn't recognize the implemented parameters.

Do you have suggestion to fix this issue ?

Best regards,

mxmgr

[Rob]

It's easier to define the parameter with the units, so "parameter-2" is 10 [m/s]
I'd also avoid using two letter labels as some are already taken by Fluent for field variables: pick a more distinctive label ie "inlet_param"
For the TUI commands it's also advisable to write them in long hand for journals as it's easier to then review what was written, and use the full syntax.
def bc zt label-1 velocity-inlet
/define/boundary-condition/zone-type label-1 velocity-inlet