Acusolve Reference Frame for Cartesian Velocity at Inlet

Jasvinder Sandhu_20853

Using Hypermesh (Acusolve Preference), i would like to specify a non-normal velocity at the inlet.

i've defined a coordinate system (global system, blue colour below), but when i reference this system & try run, i get an error:

acuPrep: Processing SIMPLE_BOUNDARY_CONDITION( "Inflow" )
acuPrep: *** ERROR: reference_frame not defined

why is it not seeing the reference frame?

any ideas please?

running with 'reference frame <unspecified>', the analysis runs fine.

thanks.

Community-Pasted-Attachment-1604656040740.png

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Bill Calver_22424

Hello Jasvinder,

The Reference Frame input field of the Simple Boundary Condition should point to a Reference Frame definition as seen here:

From your image above you could transform the (4.04, 0, 0) local vector to the global coordinate system with the same cartesian inflow velocity as you currently have defined. Alternatively, you could specify a Normal inflow velocity type and simply specify the average normal velocity magnitude. This approach will produce a parabolic inlet profile while the Cartesian type will produce a constant (slug flow) inlet profile:

-Bill

Jasvinder Sandhu_20853

Thanks for the reply.

so if i want to change the velocity (or flow rate) from being normal to the inlet & to be in a different direction, such as the X-direction below, how can i do this?

i created a rectangular system & organised it to the 'LM-blkd' reference frame.

Green below is the rectangular system, black is the inlet & red is the velocity direction i want at the inlet, so it is aligned to the local X-direction.

is this possible? i could'nt get it to work.

2nd image below is what i tried.

thanks

Community-Pasted-Attachment-1604831030766.png

Jasvinder Sandhu_20853

Thanks for the reply.

so if i want to change the velocity (or flow rate) from being normal to the inlet & to be in a different direction, such as the X-direction below, how can i do this?

i created a rectangular system & organised it to the 'LM-blkd' reference frame.

Green below is the rectangular system, black is the inlet & red is the velocity direction i want at the inlet, so it is aligned to the local X-direction.

is this possible? i could'nt get it to work.

2nd image below is what i tried.

thanks

basically i want to change the velocity direction from being normal to the inlet, to be in a direction aligned to a local rectangular coordinate system.

Bill Calver_22424

The best way to do this would be to specify the inlet velocity components relative to the global coordinate system.

-Bill