trying to identify the propagation

I have the following code. I am graphing a wave as z distance away from the origin in time. As time goes on the wave propegates forward. Im trying to identify the factor that propegates the wave forward. My goal is to make the wave approach origin as time goes on

for t=1:length(step)

upsilon=sqrt(3*((1-nu)/(1+nu))*(B/row));

expansion=exp(-z/zeta).*(1-.5.*exp(-upsilon.*step(t)/zeta))-.5.*exp(-abs(z-upsilon.*step(t))/zeta).*sign(z-upsilon.*step(t));

eta=(1-R)*((Q*Beta)/(A*zeta*C))*((1+nu)/(1-nu))*expansion;

Answer 1

[Divit]

Hi Bruce,

The code snippet you've provided is a MATLAB script that calculates the propagation of a wave as a function of time and distance from the origin. The wave's behavior is determined by several physical parameters and the expression used to calculate the variable expansion.

The factor that seems to be responsible for the propagation of the wave is "upsilon", which is multiplied by the time step "step(t)" within the "expansion" expression.

The term "exp(-abs(z-upsilon.*step(t))/zeta)" suggests that as"t" increases, the location where the wave has significant amplitude moves with velocity "upsilon". If you want the wave to approach the origin as time goes on, you would need to modify the expression so that the position of the wave's peak amplitude decreases with time.

If "upsilon" is positive and you want the wave to move towards the origin, you might need to adjust the terms involving "z-upsilon.*step(t)" to reflect the opposite direction of movement. This could involve negating "upsilon" or changing the way it interacts "z" and "step(t)". However, this change would need to be consistent with the physical model you are using.

Please ensure that any modifications you make to the code align with the physics of the problem you're trying to solve.

Hope it helps!