changes.mady.by.user Arthur Aslanyan (Nafta College)
Saved on Mar 23, 2019
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r_{wf} < r \leq r_e
p(t, r ) = p(r) \Leftrightarrow \frac{\partial p}{\partial t} = 0
\frac{\partial^2 p}{\partial r^2} + \frac{1}{r} \frac{\partial p}{\partial r} =0
p(r_e ) = p_i
\left[ r\frac{\partial p(r)}{\partial r} \right]_{r \rightarrow r_w} = \frac{q_t}{2 \pi \sigma}
p_{wf}= p(r_w ) - S \cdot r_w \, \frac{\partial p}{\partial r} \Bigg|_{r=r_w}
