Repeat Problem 8.111 if the pipes are galvanized iron and the friction factors are not known a priori.

Problem 8.111

Air, assumed incompressible, flows through the two pipes shown in Fig. P8.111. Determine the flowrate if minor losses are neglected and the friction factor in each pipe is 0.015. Determine the flowrate if the 0.5-in.-diameter pipe were replaced by a 1 -in.diameter pipe. Comment on the assumption of incompressibility.

Figure P8.111

p = 0.5 psi T= 150F 1 in. 0.50 in. T 20 ft 20 ft