Question

Notre Dame University Faculty of Engineering Mechanical Engineering Dep Water flows through cast iron pipes and between the two tanks shown in Figure P4. The free sharp edge entrance. Bd by a distance of 8 m. The water leaves Tank 1 through a contains a regular 90 threaded elbow and two unknown a regular 90° threaded elbow and a fully Branch pipeline 1 contains a regular 90 valves (valve 1 and valve 2). Branch pipeline 2 contains open gate valve. The losses to the flowing fluids throgh the junctions can be ignored. The pump adds 10 kw of a) Initially, valves 1 and 2 are fully closed foreing the fnow through branch pipeline 2 exelusively? Find the head that the pump adds to the flowing water and the flowrate. b) The unknown valves are now partially open allowing a flow of water into branch pipeline 1. The flowrate through the pump is constant and equal to the value computed in a). If the flowrate in branch pipeline l is to be 25% of the flow rate in branch pipeline 2, evaluate the loss coefficient of the partially opened valves (assumed to be equal to each other). The friction factor can be assumed constant and equal to the value computed in a). Valve 2 -4 cm 11 = 36m D,-8 cm Tank 2 Valve 1 Junction "Tank 1 pump D2-8cm 2-36 m 10-20 m Figure P4

Answer 1

Fos 0) Head adabdb pump 2a D 0

25 e-ー0.26 -o.oo.325 LlO

7.9 6-178 Q D258 2. 2a 32 ' 0.s-xagSdW69_100g.GUQ2 とVo2 20 Valve k-0.2 kV32-17、C199.oway 2019.29 Q3

H= 3897m

+ 0262 02 =0.02.6 2 2 = 38.87m Fas t 0262 ms 28 Da 七(- V/2 2epam vave 0327S X36 2 o o2036)

htog = 25.37 t l、7742k 8 + 25.37 +1.7742 K 38.87 K=3.1