Computational Aerodynamics Questions & Answers  




I'm glad to hear that. Because your post may help others, I'll give you 2 points bonus boost.




I corrected it.




Both the integral form and the differential form can be used in CFD. But we can derive the integral form by integrating the differential form over a volume.. We'll get to this at one point. Interesting question: I'll give 2 points bonus boost.




The following is always correct: $$ \frac { \partial ( {\frac {1} {2}} {\phi^2} ) } { \partial \xi} = {\phi} {\frac {\partial \phi} {\partial \xi}} $$ where $\phi$ is any property and $\xi$ can be $x$, $y$, $t$, or any coordinate. It doesn't matter if $\phi$ is $v_x$ or $t$, the above is a mathematical transformation, not a physical one. Not a bad question, I'll give you 1.5 points bonus.




This is a good question. First note that $\Gamma$ must be chosen such that it respects the dependencies we specified during the derivation. By definition, $$ \Gamma\equiv\frac{\partial \tau}{\partial t} $$ Thus, because $\tau=\tau(t)$, $\Gamma$ can not depend on $x$ or $y$. $\Gamma$ could depend on $t$ thus. We here choose it to be simply $\Gamma=1$ because that is the simplest expression that satisfies the above dependency.. I'll give you 2 points bonus boost.



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