<< Click to Display Table of Contents >> Navigation:  Sample Problems > Usage > Implicit_Curves > sine_boundary

{ SINE_BOUNDARY.PDE

 

 This example creates a sinusoidal boundary segment using

 the implicit CURVE descriptor. FlexPDE follows the given

 equation exactly, so the current point and the ending point

 must satisfy the equation or an error is issued. It starts

 tracking the4 curve in the direction specified (-X).

}

title 'Sine Boundary'

coordinates cartesian2

variables u

 

definitions

 k = 1

 bottom = -1

 

initial values u=1

 

equations

 U: div(K*grad(u)) + 4 = 0

 

boundaries

Region 1

  start(-1,bottom)

    value(u)=0  

  line to (10,bottom)

    natural(u)=0

  line to (10,2)

    value(u)=1

  { create a boundary segment that follows the equation

     y = cos(pi*x)+1, and start moving in the -X direction. }

  curve (y = cos(pi*x)+1) by (-x) to (-1,0)  

    natural(u)=0  

  line to close

 

plots

contour(u)

elevation(u) from(-1,0) to (1,0)

 

end