Some systems in fluid dynamics involve a fluid being subject to conservative body forces. Since a conservative body force is the gradient of some potential function, it has the same effect as a gradient in fluid pressure.1 It is often convenient to define a modified pressure equal to the true fluid pressure plus the potential.
Examples of conservative body forces include gravity and the centrifugal force in a rotating reference frame.
References
References
- Bansal, R. K. (February 2005). A Textbook of Fluid Mechanics. Firewall Media. ISBN 978-81-318-0294-6.