A homeowner is interested in supplying water (20C, viscosity is 1.00106m2/s) to her wood shop that is about 30m from her house. However, she is concerned about the lack of water pressure. Calculate the pressure drop she can expect for a flow rate of 10 liters per minute through a 1.5-cm copper pipe (whcih has e=0.0015mm ). Assume minor losses are negligible. Solution: Determine the friction head loss and convert it to a pressure drop - To determine the frictional factor used in Darcy-Weisbach Equation: 1. Relative roughness is =e/D= 2. Flow rate Q is Q= 3. Area of the pipe is A= 4. Water velocity is v= 5. Renold's number Re = 6. From Moody diagram: f= - To determine the frictional headloss due to friction 1. hf=f(L/D)(V2/2g)= 2. Thus the pressure drop is P= kPa