Pressure in Ansys

[4WillyWonka]

When you introduce a load of pressure on one area in ansys, in what units is it indicated?. I have read that the units are [lb/in^2] and to pass it to [kpa] it is necessary to multiply by 6.89. Is it true?

 

[Stringmaker]

Pressure is defined as force per unit area. That being the case pressures applied in the model must be calculated using proper units or converted to the proper units. It sounds like you're on the right track.

Remember that things really don't have units in Ansys. If the distance between two nodes is 1.00 this could be in inches, meters, etc. You just need to make sure temperatures, material properties, loadings, and so forth are consistent.

It's a good idea to use the /units command to declare units for the model. These units can later be referenced by you or another use using the /stat command.

-Brian

 

[4WillyWonka]

Hi Brian

I don't understand completely how Ansys works without units. I mean: when I draw any object, it is not the same thing that WP Settings are configured in cm or in m, no?

Therefore it isn't the same thing that the applied pressure is in N/m^2(Pa) or in lb/in^2.

If I use the /units command to declare units for the model, would I have to express the pressure in Pa or in lb/in^2?

I'm sorry for my poor english. Thank you.

Regards. Jorge.

 

[pja]

The governing equations of equilibrium, which all numerical software attempt to solve, are the same regardless of units used. It is up to the user to make sure the units are consistent.

 

[Stringmaker]

Jorge,
The /units command actually doesn't do anything to the geometry to scale it in any way. It can merely be used for reference. You need to make sure that if you are using inches for length and lbs for force that you apply pressure values in psi. If you were using newtons as a unit for force and meters then your pressure value would need to be in Pa. Hopefully you get the gist.

-Brian

 

[4WillyWonka]

Brian,

I think I have already understood it with the last explanation. I expect to have success.

Jorge