Question

EXAMPLE 1-1 Apply the energy equation to the situation sketched in Fig. 1-10 Solution. T upper reservoir to the free surface at position 2 of the lower reservoir. The results, wit!h cach loss term identified, are he energy equation will be applied from the free surface at position I of the 4 K, Y 2g (entrance) (pipe (eibow) friction)

to solve one design problem. You can use a programming language you are comfortable with (python, C++, Java etc.)

Question -1 specify the nominal size of clean commercial pipes required for a flow rate of 0.2 ft3/sec if the following are given

Da=Db=Dc

La=200ft

Lb=40ft

Lc=160ft

H=75 ft

Answer 1

Ans:

For this system we use the equation :

H = v2/2g[ ka + f/D(La + Lb + Lc) + 2Kb + Kv + Ke ]

For the loss coefficients,

Ka = 0.78

Kb = 30 fT

Kv = 55 fT

Ke = 1

The final equation : 75 = V²/2g[ 400f/D + 115 fT + 1.78 ]

Where fT = the turbulent friction factor

Here We use the diameter as the iteration variable and compute the head

D (ft)	ϵ/D	V (ft/s)	ReD (*105)	F	fT	[ 400f/D + 115 fT + 1.78 ]	H (ft)
0.1	0.00150	25.46	1.819	0.0228	0.023	95.625	963.65
0.2	0.00075	6.37	9.095	0.0213	0.018	46.45	29.30
0.15	0.00100	11.32	1.213	0.0216	0.020	61.68	122.88
0.14	0.00107	12.99	1.299	0.0218	0.020	66.36	174.10
0.145	0.00103	12.10	1.254	0.0217	0.020	63.94	145.54
0.147	0.00102	11.78	1.237	0.0216	0.020	58.77	126.79
0.146	0.00103	11.95	1.246	0.0217	0.020	63.53	141.053