Uniform pressure along the fracture

we give a complementary solution to Example 2-5 and consider the flow of a constant density liquid into a fracture held at a constant pressure pf. 

the derivative pf (0 vanishes identically, and Equation 2-15 reduces to -H 

Note that the integral of f(x) over (-l,-l-l) equals (H - pf )/ loge2, a result consistent with Equation 2-113 when Q) = pf and C2 = Cq = 0. Next, from Equations 2-19 and 2-20, respectively, we have 

The formula for the total volume flow rate Q is given in Equation 2-114, where Cq = pf and C2 = Cq = 0. Since H is now determined, the source strength 

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