Explore BrainMass

Explore BrainMass

    Dirichlet Problems

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    See the attached file.

    1. Consider the Dirichlet Problem where the temperature within a rectangular plate R is steady-state and does not change with respect to time. Find the temperature u(x,y) within the plate for the boundary conditions below and where (see attached).

    2. Solve the Dirichlet problem for steady-state (constant with respect to time) temperature within the wedge shown below. Find the temperature (see attached) within the wedge. The temperature along the arc is (see attached).

    Hint: For the solution in ρ, which is the radius, the coefficient for one of the two independent solutions must be zero, since the solution must be finite (can't go to infinity) when ρ=0.

    © BrainMass Inc. brainmass.com March 5, 2021, 12:44 am ad1c9bdddf


    Solution Preview

    The solution is attached below in two files. the files are identical in content, only differ in format. The first is in MS Word format, while the other is in Adobe pdf format. Therefore you can choose the format that is most suitable to you.

    The two-dimensional heat equation is:
    Under steady state conditions and the problem turns into Laplace equation:
    In the case of the rectangle the boundary conditions are:
    Note that (1.4) are periodic boundary conditions that tells us w should find the eigenfunctions in the form of .
    We start with separation of variables. We write the temperature function as a product of two single-variable independent functions:

    Plugging it back into the equation we obtain:

    So each side of equation (1.7) is completely independent of the other, and since it is true for any both sides must equal the same constant:
    The conditions for are given in (1.4):
    Now we need to solve equation (1.8) for :

    Case 1:
    The equation becomes:
    Its solution is:
    Applying boundary ...

    Solution Summary

    The solution finds the temperature within the plate for the boundary conditions. Dirichlet problems are analyzed.