MATLAB Surface Plot in Matlab (Cylindrical Coordinates)

AI Thread Summary
To plot the steady state temperature solution u(r,z) in MATLAB for a circular cylinder, the equation u(r,z) = u_0 * sinh(λz) * J_0(λr) is used, where r and z are defined within specific ranges. The solution is independent of the angular coordinate θ, simplifying the plotting process. A one-dimensional linspace vector is created for both r and z, which are then evaluated using the sinh and J0 functions. To visualize u as a surface, it is suggested to convert r to Cartesian coordinates (x, y) and create a fine grid for smooth surface representation. Implementing these steps will allow for an effective 3D surface plot in MATLAB.
phioder
Messages
25
Reaction score
0
Hello

Trying to plot in MATLAB the final solution equation u(r,z) of the steady state temperatures in the circular cylinder

u(r,z) is defined in cylindrical coordinates and I'm confused trying to understand also how MATLAB plots a mesh.

After some simplification The final solution looks like:

u(r,z) = u_0 \cdot sinh(\lambda z) \cdot J_0(\lambda r)

and it is defined in

0<r<2

0<z<4

\lambda = constant

The solution of the problem is not defined in \theta and most of 3d plot examples I have found yet on the web define a theta vector.

In MATLAB a one dimensional linspace vector for r, one for z is defined and later evaluated with sinh() and J0(). The resulting vector are multiplied as sinh().*J0(), to get again a one dimensional vector, all vectors are of the same size, so I suppose the vectors are right.

Now the question is, is it possible to display u(x,t) as a surface with Matlab? If yes, could anyone give me some kind of tip, hint on how to implement and understand the plot?

Best Regards and Thank you
 
Last edited:
Physics news on Phys.org
The solution is indepeendent of \theta, so it doesn't matter, I'd set r = \sqrt{x^2+y^2} and plot in 3-d on that grid. Make x and y on a fine enough grid that you can get a bunch of points for a smooth surface.
 

Similar threads

Replies
1
Views
2K
Replies
2
Views
2K
Replies
2
Views
3K
Replies
5
Views
5K
Replies
7
Views
3K
Replies
3
Views
8K
Back
Top