Operating Conditions (( Gravity ))
 

Hello All.

I just ask to Seattle the issue of Operating Conditions ( Gravity ).
I was working on 2D horizontal Geometries . In this case was selection Gravity from the Operating Conditions by put a tech there then type -9.81 in y-axis as we learned b4.


So for 2D inclined and vertical (Assisted and opposing) geometries how to control the issue of gravity .

Same question with 3D (Horizontal and different inclinations angles)
I was using the next:

g(x)= -9.81 cos(theta)
g(y)= -9.81 sin (theta)


So how about Z-axis in 3D and wht are the rules of setting gravity.



One more question?

In Operating Conditions panel there is a reference pressure location
when and where do I apply this ???

For gravity, you define the direction in which gravity is directed.
If gravity is directed into the negative z-direction, you use (0,0,-9.81).
If it is into the positive x-direction, you use (9.81,0,0).

I am not sure if this answers your question, because I don't really understand what your question is. I don't know what you mean by "the rules of setting gravity". Just set gravity in the way that you need it...

Hellllo Pakk

Thanks for your reply. Actually I know how to set the gravity as a number and direction but I wanna to know the general rule of gravity in multi directions and multi geometries


Is there a rule or formula to follow if the geometry was horizontal or vertical and so on.


tq

Still not sure what you mean by "general rule of gravity".

What you should do is:
1. Find the components of the gravity vector.
2. Put them in Fluent.

For number 1, you have to know stuff about angles. You know, with the sines and the cosines you learned about in school. Is that the problem?

Dear.

Who does NOT know the equations of Gravity Components of X and Y in Inclined Plan

but In 3D Geometries how to set my Gravity Acceleration of X-Y and Z

In Horizontal or Inclined Orientations ( Fluent )

TQ


tQ

You still do not make clear what your question is...

If in 2D, gravity is directed in the negative y-direction, you put the gravity as:
gx = 0 m/s, gy = -9.81 m/s.
If in 2D, gravity is directed in the negative x-direction, you put the gravity as:
gx = -9.81 m/s, gy = 0 m/s.

In 3D, it is EXACTLY THE SAME, only you have one more component.
If in 3D, gravity is directed in the negative y-direction, you put the gravity as:
gx = 0 m/s, gy = -9.81 m/s, gz = 0 m/s.
If in 3D, gravity is directed in the negative x-direction, you put the gravity as:
gx = -9.81 m/s, gy = 0 m/s, gz = 0 m/s.
If in 3D, gravity is directed in the negative z-direction, you put the gravity as:
gx = 0 m/s, gy = 0 m/s, gz = -9.81 m/s.

And if it is at an inclined angle, you need to calculate the components of gravity using the sine and cosine equations.

If this does not answer your question, please rephrase your question, make it clear which step is giving you problems. I have tried my best to help you so far, but you need to be clear about what you want to know, otherwise I give up.