changes.mady.by.user Arthur Aslanyan (Nafta College)
Saved on Mar 09, 2019
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\frac{\partial p}{\partial t} = \chi \, \left[ \frac{\partial^2 p}{\partial t^2} + \frac{1}{r} \frac{\partial p}{\partial r} \right]
p(t=0,r) = p_i
p(t, r=\infty) = p_i
\left[ r \frac{\partial p}{\partial r} \right]_{r=0} = - \frac{q_t}{2 \pi \sigma}
p(t,r) = p_i -+ \frac{q_t}{4 \pi \sigma} {\rm Ei} \left(-\frac{r^2}{4 \chi t} \right)