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Next: Helmholtz Equation. Steady with Up: Radial-spherical coordinates. Steady 1-D Previous: Solid sphere,steady 1-D.

Hollow Sphere, steady 1-D.

RS11 Hollow sphere, a $ \leq$ r $ \leq$ b, with G = 0 (Dirichlet) at r = a and at r = b.

4$\displaystyle \pi$GRS11(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
(b-r^{\prime })(1-a/r)/[r^...
...-r)(1-a/r^{\prime })/[r(b-a)] & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
(b-r^{\prime })(1-a/r)/[r^{\prime }(b-a)] & \t...
...
& \\
(b-r)(1-a/r^{\prime })/[r(b-a)] & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
(b-r^{\prime })(1-a/r)/[r^{...
...-r)(1-a/r^{\prime })/[r(b-a)] & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS12 Hollow sphere, a $ \leq$ r $ \leq$ b, with G = 0 (Dirichlet) at r = a and $ \partial$G/$ \partial$r = 0 (Neumann) at r = b.

4$\displaystyle \pi$GRS12(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
1/a-1/r & \text{for }r<r^{\prime } \\
1/a-1/r^{\prime } & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
1/a-1/r & \text{for }r<r^{\prime } \\
1/a-1/r^{\prime } & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
1/a-1/r & \text{for }r<r^{\prime } \\
1/a-1/r^{\prime } & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS13 Hollow sphere, a $ \leq$ r $ \leq$ b, with G = 0 (Dirichlet) at r = 0 and k$ \partial$G/$ \partial$r + h2G = 0 (convection) at r = b. Note B2 = h2b/k.

4$\displaystyle \pi$GRS13(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{c}
\lbrack B_{2}(\frac{a}{r}-\...
...] \\
\div (B_{2}a-B_{2}b-a);\;\text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{c}
\lbrack B_{2}(\frac{a}{r}-\frac{ba}{rr^{\prime ...
...prime }}+1] \\
\div (B_{2}a-B_{2}b-a);\;\text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{c}
\lbrack B_{2}(\frac{a}{r}-\f...
...] \\
\div (B_{2}a-B_{2}b-a);\;\text{for }r>r^{\prime }
\end{array}
}\right.$

RS21 Hollow sphere, a $ \leq$ r $ \leq$ b, with $ \partial$G/$ \partial$r = 0 (Neumann) at r = a and G = 0 (Dirichlet) at r = b.

4$\displaystyle \pi$GRS21(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
1/r^{\prime }-1/b & \text{for }r<r^{\prime } \\
1/r-1/b & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
1/r^{\prime }-1/b & \text{for }r<r^{\prime } \\
1/r-1/b & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
1/r^{\prime }-1/b & \text{for }r<r^{\prime } \\
1/r-1/b & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS22 Hollow sphere, a $ \leq$ r $ \leq$ b, with $ \partial$G/$ \partial$r = 0 (Neumann) at both boundaries. Note that this geometry requires a pseudo GF, denoted H. The temperature solution found from a pseudo GF requires that the total volumetric heat flow is equal to the boundary heat flow, and the spatial average temperature in the body must be supplied as a known condition.

4$\displaystyle \pi$HRS22(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
\lbrack r^{2}/2+\left( r^{...
...ime
}+b^{3}/r]/(b^{3}-a^{3}) & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
\lbrack r^{2}/2+\left( r^{\prime }\right) ^{2}...
...{3}/r^{\prime
}+b^{3}/r]/(b^{3}-a^{3}) & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
\lbrack r^{2}/2+\left( r^{\...
...ime
}+b^{3}/r]/(b^{3}-a^{3}) & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS23 Hollow sphere, a $ \leq$ r $ \leq$ b, with $ \partial$G/$ \partial$r = 0 (Neumann) at r = a and k$ \partial$G/$ \partial$r + h2G = 0 (convection) at r = b. Note B2 = h2b/k.

4$\displaystyle \pi$GRS23(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
1/r^{\prime }+(1/B_{2}-1)/...
...rime } \\
1/r+(1/B_{2}-1)/b & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
1/r^{\prime }+(1/B_{2}-1)/b & \text{for }r<r^{\prime } \\
1/r+(1/B_{2}-1)/b & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
1/r^{\prime }+(1/B_{2}-1)/b...
...rime } \\
1/r+(1/B_{2}-1)/b & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS31 Hollow sphere, a $ \leq$ r $ \leq$ b, with - k$ \partial$G/$ \partial$r + h2G = 0 (convection) at r = a and G = 0 (Dirichlet) at r = b. Note B1 = h1a/k.

4$\displaystyle \pi$GRS31(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{c}
\lbrack B_{1}\frac{ba}{rr^{...
...] \\
\div (B_{1}b-B_{1}a+b);\;\text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{c}
\lbrack B_{1}\frac{ba}{rr^{\prime }}-B_{1}\frac...
...r}+B_{1}+1] \\
\div (B_{1}b-B_{1}a+b);\;\text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{c}
\lbrack B_{1}\frac{ba}{rr^{\...
...] \\
\div (B_{1}b-B_{1}a+b);\;\text{for }r>r^{\prime }
\end{array}
}\right.$

RS32 Hollow sphere, a $ \leq$ r $ \leq$ b, with - k$ \partial$G/$ \partial$r + h2G = 0 (convection) at r = a and $ \partial$G/$ \partial$r = 0 (Neumann) at r = b. Note B1 = h1a/k.

4$\displaystyle \pi$GRS32(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{cc}
-1/r-(1/B_{1}+1)/a & \text...
...
-1/r^{\prime }-(1/B_{1}+1)/a & \text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{cc}
-1/r-(1/B_{1}+1)/a & \text{for }r<r^{\prime } \\
-1/r^{\prime }-(1/B_{1}+1)/a & \text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{cc}
-1/r-(1/B_{1}+1)/a & \text{...
...
-1/r^{\prime }-(1/B_{1}+1)/a & \text{for }r>r^{\prime }
\end{array}
}\right.$

RS33 Hollow sphere, a $ \leq$ r $ \leq$ b, with - k$ \partial$G/$ \partial$r + h1G = 0 (convection) at r = a and k$ \partial$G/$ \partial$r + h2G = 0 (convection) at r = b. Note B1 = h1a/k and B2 = h2b/k.

4$\displaystyle \pi$GRS33(r $\displaystyle \left\vert\vphantom{ \,r^{\prime }}\right.$ r$\scriptstyle \prime$$\displaystyle \left.\vphantom{ \,r^{\prime }}\right.$) = $\displaystyle \left\{\vphantom{
\begin{array}{c}
\lbrack B_{1}(\frac{a}{r}+1...
..._{2}b+B_{1}a+B_{1}B_{2}(b-a)];\;\text{for }r>r^{\prime }
\end{array}
}\right.$$\displaystyle \begin{array}{c}
\lbrack B_{1}(\frac{a}{r}+1)+B_{1}B_{2}(1-\frac...
... \lbrack B_{2}b+B_{1}a+B_{1}B_{2}(b-a)];\;\text{for }r>r^{\prime }
\end{array}$ $\displaystyle \left.\vphantom{
\begin{array}{c}
\lbrack B_{1}(\frac{a}{r}+1)...
..._{2}b+B_{1}a+B_{1}B_{2}(b-a)];\;\text{for }r>r^{\prime }
\end{array}
}\right.$


next up previous
Next: Helmholtz Equation. Steady with Up: Radial-spherical coordinates. Steady 1-D Previous: Solid sphere,steady 1-D.
Kevin D. Cole
2002-12-31