Difference between revisions of "Conservation Laws and Boundary Conditions"

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The Ocean Environment
 
The Ocean Environment
  
NON LINEAR FREE-SURFACE CONDITION
+
Non Linear Free-surface Condition
  
(X,Y,Z): EARTH FIXED COORDINATE SYSTEM
+
(X,Y,Z): Earth Fixed Coordinate System
X: FIXED EULERIAN VECTOR
+
X: Fixed Eulerian Vector
v: FLOW VELOCITY VECTOR AT X
+
v: Flow Velocity Vector At X
: FREE SURFACE ELEVATION
+
: Free Surface Elevation
  
 
Assume ideal fluid (No shear stresses) and irrotational flow:
 
Assume ideal fluid (No shear stresses) and irrotational flow:
  
<center><math>\Delta \times V = 0</math></center>
+
<center><math>\nabla \times \overrightarrow{V} = 0</math></center>
  
 
Let:
 
Let:
  
<center><math>V = \Delta \Phi \to \Delta \times \Delta \Phi = 0 </math></center>
+
<center><math> \overrightarrow{V} = \nabla \Phi \to \nabla \times \nabla \Phi = 0 </math></center>
  
 
Where <math>\Phi(X,t) is the velocity potential assumed sufficiently continuously differentiable.
 
Where <math>\Phi(X,t) is the velocity potential assumed sufficiently continuously differentiable.

Revision as of 11:16, 16 January 2007

The Ocean Environment

Non Linear Free-surface Condition

(X,Y,Z): Earth Fixed Coordinate System X: Fixed Eulerian Vector v: Flow Velocity Vector At X

Free Surface Elevation

Assume ideal fluid (No shear stresses) and irrotational flow:

[math]\displaystyle{ \nabla \times \overrightarrow{V} = 0 }[/math]

Let:

[math]\displaystyle{ \overrightarrow{V} = \nabla \Phi \to \nabla \times \nabla \Phi = 0 }[/math]

Where [math]\displaystyle{ \Phi(X,t) is the velocity potential assumed sufficiently continuously differentiable. Potential flow model of surface wave propagation and wave-body interactions very accurate. Few important exceptions will be noted. Conservation of mass: \lt center\gt \lt math\gt \Delta \dot V = 0 }[/math]