Formulating Ripple Equation for 2D Symmetry

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The discussion focuses on formulating a 2D ripple equation, μ(x,y), that is symmetric about the y-axis, has maximum amplitude at x=0, and fades symmetrically to zero without negative values. Participants suggest using polar coordinates to satisfy the symmetry and propose solving the wave equation under these conditions. Clarification is sought on whether a one-dimensional or two-dimensional solution is desired, with a preference for a one-dimensional function. The equation y(x) = Ae^{-bx}cos(x) is mentioned as a potential solution, emphasizing the need for a proper mathematical model rather than arbitrary function selection. The conversation highlights the importance of defining source functions and initial displacements in the modeling process.
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I want to formulate an approx 2D ripple equation μ(x,y). It should satisfy following:

1) it should have highest amplitude on y-axis at x=0. It should be symmetrical about y axis. It should fade away at some x on both positive and negetive x-axis symmetrically. Fading in a way of decreasing amplitude. It should not give negetive value of y.

2) most important. The square of norm of μ should be normalized in infinity.

I am not good at math but this is integral part of my project. It can be visualized as : consider x-axis as still surface of water and you drop a pebble on it. But it should be shifted upwards such that it should not fall in negetive y axis. Also it should be preferably in cartesian co ordinates
 
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Do you mean a "ripple" like function on a plane surface that models a water wave?
Your conditions are:
1.symmetric across the y-axis (simply solve in polar coordinates, with the condition that the function obeys ψ(r,θ)=ψ(r,θ+pi)
2.Falls off at infinity, that's fine we'll just pick a solution that does this

And then simply solve the wave equation in polar coordinates with these conditions.
Ta-da.

However, could you specify how you want it?
There are a few things you have to consider.
1.Source function?
2.Initial displacement?

Also, you cannot limit the function to be positive, that would be non-physical. Real water ripples go both ways.Edit: Now I'm a bit confused, do you want a plane solution or a one dimensional solution? I thought you meant the former, seeing as you referred to the function as a "ripple equation" and specified two arguments for it (mu(x,y)), but then I read your conditions again and you also imply you want a one dimensional one. (i.e. y(x))
 
Last edited:
HomogenousCow said:
Do you mean a "ripple" like function on a plane surface that models a water wave?
Your conditions are:
1.symmetric across the y-axis (simply solve in polar coordinates, with the condition that the function obeys ψ(r,θ)=ψ(r,θ+pi)
2.Falls off at infinity, that's fine we'll just pick a solution that does this

And then simply solve the wave equation in polar coordinates with these conditions.
Ta-da.

However, could you specify how you want it?
There are a few things you have to consider.
1.Source function?
2.Initial displacement?

Also, you cannot limit the function to be positive, that would be non-physical. Real water ripples go both ways.


Edit: Now I'm a bit confused, do you want a plane solution or a one dimensional solution? I thought you meant the former, seeing as you referred to the function as a "ripple equation" and specified two arguments for it (mu(x,y)), but then I read your conditions again and you also imply you want a one dimensional one. (i.e. y(x))

I did a silly mistake there, I want 1D solution of it. :-P
 
I want it in form y(x)
 
y(x) = Ae^{-bx}\cos{x} fits the bill. What exactly are you trying to model? You're better off deriving a differential equation and trying to solve it than just picking out a function from random that meets certain requirements.
 
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