Questions on codes of Panel Method (Multi-Airfoil) #2
Description
Hello Mr. Josh, I have some question in your code, and I've send you a email that you haven't replied (attached below). Since I can't attach my codes on GitHub, maybe you can see my code on my page if you have time to do so.
Dear Engineer Josh:
My name is Bruce Mingyu Han, and I'm currently an undergraduate student of Department of Computational Mathematics in Peking Universtiy. Recently, I was required to study panel method for potential flow.
I can say that reading your website and MATLAB programs is enjoyable and really helped me a lot, but maybe there's some little mistake in programs for Multi-Airfoil VPM. After running your code <SPVP_Airfoil_N.m> and inspect the matrix K, one can find that there exists i\ne j such that K(i, j)=0. However, this is impossible since K is defined as, the contribution of unit vortex strength on panel j, to the tangential velocity on control point of panel i.
The mistakes might occur in code <COMPUTE_KL_VPM_N.m> and maybe my code <COMPUTE_KL_VPM_N1.m> could fix it. My idea is that, after adding an imaginary panel to make the two airfoils geometrically an airfoil, we could calculate it's K. And since the contribution as which K is defined is invariant to the process of adding a panel, we could get the K we required simply through slice of matrix.
Since I'm just a beginner to mechanics and computational mathematics, please don't blame me for my wrong opinion. And I would highly appreciate it if you could reply me for this issue.
Again, thank you for your well-designed website and kindness to help me.
Best regards,
Bruce Mingyu Han