Computational Aerodynamics Questions & Answers  




We can set $\Gamma$ to any value as long as it respects the dependency we originally specified. That is, $\Gamma=\partial\tau/\partial t$ should be such that $\tau=\tau(t)$. Thus, we can choose $\Gamma$ to be $1$ or $t$ or $t^2$ but not $x$ or $tx$, etc. Here, it is perfectly fine to choose $\Gamma=1$. One advantage of choosing $\Gamma=1$ is that $$ \frac{\partial}{\partial\tau}\left(\frac{\partial\tau}{\partial t}\right) = \frac{\partial}{\partial\tau}\left(\Gamma\right) = \frac{\partial}{\partial\tau}\left(1\right) = 0 $$ If $\Gamma$ would have been chosen as $t$ or $t^2$, then the latter wouldn't be 0, and this would lead to $\Phi_1\ne 0$, and this would prevent us to write the Euler equations in generalized coordinates in conservative form. I'll give you 2 points bonus boost.




Warp is a binary file (executable), so it can not be opened in pluma. With pluma you can open text files like .wrp or .txt or .c etc. Please don't do assignment #4 now: the tgz package is not complete yet. I'll explain what to do in assignment 4 tomorrow.




Hmm, I am not sure what your first question is.. As for the second, 'NO' does not make the mesh equally 1, it simply needs to be used when the block is 1D (when there are no segments along a certain dimension). I'll give you 1 point bonus boost.




First, the command is Join(), not Joint(), and is case sensitive. So, if you use JOIN or join it will not work: it has to be spelled Join. For the third mesh, you can not use Join(is,js,ie,je,j,GG..) because the GG segment grabs the spacing from the mesh along the j coordinate. So in this case, he will set the first grid spacing (between j=js and j=js+1) to the distance between the point (i,js1) and the point (i,js). However, there is no point (i,js1) because it is outside of the domain. Good question: 2 points bonus boost.




You are not wrong.. Rather, I forgot to include some term. It should have been written: $$ \rm js1=round(0.5 * (jejs))+js; $$ and $$ \rm is1=round(0.3*(ieis)/2)+is; $$ Good observation: 2 points bonus boost.




That's right: I fixed it. I'll give you 1 point bonus boost because your typesetting was hard to read.




Yes, absolutely, you don't need to calculate $\Omega$ in this case. But if you choose not to calculate it, you have to explain clearly how $\Omega$ cancels out. Once $\Omega$ disappears from the terms, then there is of course no need to calculate it. Good observation: 2 points bonus.




Well, the file name should end with .vtk in order to be read in paraview.. I'll give you 1 point bonus boost.




The first two zeros in the Corners() command are for the $x$ and $y$ positions of the lowerleft corner. The next two values are for the $x$ and $y$ positions of the upperright corner. For the second question, yes, if is2 depends on is3, then you should initialize is3 before initializing is2. Two points bonus boost.




Hm, I don't understand what could be wrong.. You need to explain this more carefully.




An easy way around this is by moving the window so you can see the buttons at the bottom. You can move the window by pressing the key “alt”, the left mouse button, and moving the mouse around. Alternately, you can increase the resolution of your screen, but this is more involved..




Hmm, I didn't mention about the shock today and there is no reason to at this stage.. But I'll give you 0.5 point bonus for the effort.



$\pi$ 