Difference between revisions of "Laplace's Equation"

From WikiWaves
Jump to navigationJump to search
 
Line 1: Line 1:
The velocity potential satisfies the Laplace equation because of the assumptions that the fluid is inviscid, incompressible, and irrotational.
+
The velocity potential satisfies Laplace equation if we can assume that the fluid is inviscid, incompressible, and irrotational.
 +
 
 +
Laplace's equation is the following in two dimensions
 +
 
 +
<math>\Nabla^2\phi = \frac{\partial^2 \phi}{\partial x^2}
 +
+ \frac{\partial^2 \phi}{\partial z^2} = 0</math>
 +
 
 +
and in three dimensions
 +
 
 +
<math>\Nabla^2\phi = \frac{\partial^2 \phi}{\partial x^2}
 +
+ \frac{\partial^2 \phi}{\partial y^2}+ \frac{\partial^2 \phi}{\partial z^2} = 0</math>
 +
 
 +
The typical solution to Laplace's equation oscillates in one direction and
 +
decays in another. The linear water wave arises as a boundary wave which
 +
decays in the vertical condition and has wave properties in the horizontal
 +
direction.

Revision as of 11:13, 24 May 2006

The velocity potential satisfies Laplace equation if we can assume that the fluid is inviscid, incompressible, and irrotational.

Laplace's equation is the following in two dimensions

[math]\displaystyle{ \Nabla^2\phi = \frac{\partial^2 \phi}{\partial x^2} + \frac{\partial^2 \phi}{\partial z^2} = 0 }[/math]

and in three dimensions

[math]\displaystyle{ \Nabla^2\phi = \frac{\partial^2 \phi}{\partial x^2} + \frac{\partial^2 \phi}{\partial y^2}+ \frac{\partial^2 \phi}{\partial z^2} = 0 }[/math]

The typical solution to Laplace's equation oscillates in one direction and decays in another. The linear water wave arises as a boundary wave which decays in the vertical condition and has wave properties in the horizontal direction.