Drinking straws are to be used to improve the air flow in a pipe-flow experiment. Packing a section of the air pipe with drinking straws to form a "laminar flow element" might allow the air flow rate to be measured directly, and simultaneously would act as a flow straightener. To evaluate this idea, determine

(a) the Reynolds number for flow in each drinking straw,

(b) the friction factor for flow in each straw, and

(c) the gage pressure at the exit from the drinking straws. For laminar flow in a tube, the entrance loss coefficient is \(K_{\text {ent }}=1.4\) and \(\alpha=2.0\). Comment on the utility of this idea.

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L 230 mm- D = 63.5 mm Q = 100 m/hr Straws (d 3 mm) P8.152