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Next: 2D corner flow Up: 3.7 - Simple Potential Previous: Solution: radius of the

Stream + Dipole: circles and spheres


\begin{figure}
\centering\epsfig{file=lfig1019.eps,height=1in,clip=}\end{figure}

2D:


\begin{align}\phi = & Ux + \frac{\mu x}{2\pi r^2}, \mbox{\ where \ } x = r\cos \...
...al r} = \cos \theta \left( {U-\frac{\mu }{2\pi r^2}}
\right) \notag
\end{align}

So $V_r = 0$ on $ r = a = \left. {\sqrt {\frac{\mu
}{2\pi U}} } \right\} $ (which is the K.B.C. for a stationary circle radius a) or choose $\mu = 2\pi Ua^{2}$.

Steady flow past a circle (U,a):


\begin{figure}
\centering\epsfig{file=lfig1020.eps,height=1.8in,clip=}\end{figure}


\begin{displaymath}\begin{array}{l}
\phi = U\cos \theta \left( {r + \frac{a^2}{...
...ial velocity } \\
\end{array}} \right. \\ \end{array} \notag
\end{displaymath}  


\begin{figure}
\centering\epsfig{file=lfig1021.eps,height=1in,clip=}\notag
\end{figure}

Illustration of the points where the flow reaches maximum speed around the circle.

3D:


\begin{figure}
\centering\epsfig{file=lfig1022.eps,height=1.6in,clip=}\notag
\end{figure}


\begin{displaymath}\begin{array}{l}
\phi = Ux + \frac{\mu }{4\pi }\frac{\cos \t...
...{\mu }{2\pi U}} \mbox{\ or \ } \mu = 2\pi Ua^3
\\
\end{array}\end{displaymath}

Steady flow past a sphere (U, a):


\begin{displaymath}\begin{array}{l}
\phi = \mbox{U}\cos \theta \left( {r + \fra...
...eta = \frac{\pi }{2} \\
\end{array}} \right. \\
\end{array}\end{displaymath}


\begin{figure}
\centering\epsfig{file=lfig1023.eps,height=2in,clip=}\notag
\end{figure}



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