Finite difference method in fortran

[alexser]

1. I have problem numerical solving of PDE with finite difference method in fortran. it is about optical fibers. At the beginning of the fiber the delta impuls is inserted, and I need function at the end of the fiber.



2. The equation is given in attachement as the code in fortran



3. The problem is that I know that the function at the end of the fiber should drift towards 0 (on X axis) for lenghts of fiber over 30m, but it does not. The problem is in the code but I cannot find where.

If someone could help me I would appreciate it

 

[Jhero]

.Hello,

I would be happy to assist you with your problem in solving the PDE with finite difference method in Fortran. From your description, it seems like you are trying to model the behavior of optical fibers using a numerical approach. This is a common technique used in many fields of science and engineering, and it can be quite challenging to get accurate results.

First, I would recommend checking your code for any errors or typos. Even a small mistake can greatly affect the accuracy of your results. You can also try debugging your code by printing out intermediate values to see where the problem might be occurring.

Additionally, I would suggest checking the boundary conditions of your problem. These conditions play a crucial role in the behavior of the function at the end of the fiber. If they are not properly defined or implemented in your code, it can lead to incorrect results.

Another important factor to consider is the numerical stability of your method. Some PDEs can be very sensitive to small changes in initial conditions or parameters, and this can cause the function to behave differently than expected. You may need to adjust your parameters or try a different numerical method to improve the stability of your solution.

Lastly, I would recommend consulting with a colleague or a mentor who has experience in solving PDEs with finite difference methods in Fortran. They might be able to provide valuable insights and help you identify the source of the problem.

I hope this helps. Good luck with your research!