## Fluids

#### value of gravitational acceleration.

• pcsingh
Subscriber

Good evening!

In my case, fluid flows from top to bottom through a vertical pipe. Because it is an axis-symmetric problem, I have chosen to solve it horizontally, as illustrated in the figure. The left side of the geometry is designated as the inlet boundary condition, while the right side is designated as the outlet boundary condition. I used 0 for the y component of gravitational acceleration. I'm not sure about the value of gravitational acceleration. What should I enter for the x component of gravitational acceleration?

• pcsingh
Subscriber

Origin is taken on the left side of the above figure (bottom point of the inlet).

• SRP
Subscriber

Hi,

If you want the motion to go from top to bottom, or from +x to -x, you can use -9.81 in the x direction for gravitational acceleration.

Thank you

• pcsingh
Subscriber

Thank you @SRP sir.

I have chosen the bottom point of the inlet as the origin and flow are happening from left (inlet) to the right (outlet), as shown in the figure. Then, in this case, the value of g will be 9.81 in the x direction. Please correct me if I am wrong.

Regards

Prakash Singh