Question

Cicciarelli Farms (est. 2013) has 40 blueberry bushes that each require 5 gal of water every day. Water at 60? is pumped through 300 ft of 1” NPS, schedule 40 steel pipe by a pump with a 49.6 ft head from a pond that is 20 ft below the blueberry bushes. There is a pressure regulator before the drip tubing that keeps the pressure to the soaker hose from exceeding 25 psia. - The pump is set on a daily timer to water the blueberry bushes. Approximately how long should Dr. Cicciarelli set the timer for?

Answer 1

water properties at 60 ^oC

density = 983.3 Kg/m³

viscosity = 0.467*10^-3 Pa.sec

head provided by the pump = (49.6 ft) 15.118 m

height of bushes = (20 ft) 6.096 m

lenght of the pipe = (300 ft) 91.44 m

let the flow of water in the pipe be laminar

by applying bernaulli equation

15.118 = 6.096 + (32VL)/() + V²/2g

solving the quadratic equation for the value of V

V = 11.317 m/sec

volumetric flow rate of water = 5.73 liters/sec

water required per day in liters 757.082 liters/day

timer should be set for 2.202 minutes

this answer is for laminar flow for turbulent flow darcy's friction factor is required