Figure shows a water tank and a pipe line consists of entrance, valve and bends.

Question

Figure shows a water tank and a pipe line consists of entrance, valve and bends. Water exits the pipe as free jet. The cross-sectional area of the pipe is 0.lm2. The friction factor of the pipe line is 0.002. The loss coefficient of the entrance, bends, and valve (at full open) are shown in Figure. You can assume properties of water as mu = 1.1 times 10-3 N middot s/m2, rho = 1000kg/m3 and g= 10m/s2. With the given dimensions and water properties, please find: The exit velocity and volume flow rate of water if both major and minor losses are neglected? (Can Bernoulli equation be used? Why) The exit velocity of water if both major and minor losses are considered? Based on answer of (b). find the pressure drop due to major and minor loss, respectively? Based on answer (b). find the major head loss of pipe line from entrance to exit? Note: You don't need to finish (e) and (f) bus should think about how to solve these two questions. The pressure of water at point (3) when both major and minor losses are considered? The pressure at point (3) when valve is closed (flow rate is "0". It is then a static case)

Explanation / Answer

height= 20+5+5=30m pipe length =10+5+5+10=30m a. mgh=0.5*m*V^2 9.81*30=0.5V^2 V=24.261m/s Volumetric flow rate= 24.261*0.1 =2.4261 m^3/s b. hl=((0.002*30/(2*(0.1/3.142)^0.5)+0.2+0.3+1.5+1)*V^2)/(2*9.81) hl=0.161476077*V^2 30=V^2/2*9.81+0.161476077*V^2 V=11.8833 m/s c. total head loss =24.261-11.8833=12.3777 (Mistake used V not head loss sorry) head loss due to major losses=((0.002*30/(2*(0.1/3.142)^0.5))/(0.002*30/(2*(0.1/3.142)^0.5)+0.2+0.3+1.5+1))*total head loss =(0.16816/3.16816)*11.8833 =0.630745575m head loss due to minor losses= (3/3.16816)*11.8833 =11.25255442m pressure drop P=p*hl*g 110.3875589kpa d.hl=11.25255442m e.this can be solved in a similar manner just by substituting the respective K values of each bend where you substituted the total K of 3 and also the major friction factors where you use the L of the length of pipe till that bend . headloss= (Kl+f*L/D)/3.16816*11.8833 =((0.2+0.3+(0.002*15/(2*(0.1/3.142)^0.5))/3.16816)*11.8833 =2.19079m I made a mistake in the beginning of C i don't feel like correcting it so hope this sort of help

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