Question

Question 1. Explain briefly () Factors affecting head losses in water pipe networks Question 2 Water is fully flowing into a 120 m long and 50 mm diameter horizontal Circular pipe at 42°C and an average flow velocity of 3.6 m/sec. ps 1008 kg/m' and Ruestion 4 Given that Waste Water is flowing uniformly and Half Fully into a 24 m diameter channel made from smoothly finished concrete. What is the minimum required channel bed slope in mm) to reach a minimum flow rate of 9800 l/sec? كلية الهندسة College of Engineering (10 Marks) (a) Different water demand/consumption types. (b) Factors affecting water demand/consumption (10Marks) (10Marks) SIO * 103-10-'N sec./m. Determine the "IES DISPLAY (a) Type of flow, and why? (10Marks) (b) Total had loss throughout the flow pipe. (10 Marks) (c) Minimum pump power to overcome the head losses. (10Marks) In 3. Solve the pipe network flow shown below using only two iterations of Williams Method Take C = 100. (30 Marks) Flow 60 sec MOO MTUPON Rate b 18 Usec. Pipe Diameter Length Name im) (u/sec) 210 420 log ab 640 19 bc 150 62 Usec. 43 420 210 20 Used zlog In DO! sin costan + 1 W C hyp cd 23 640 150 ad SebM+ INS 9 DEL AC 1.07-10 N.sec/m? (30 Marks) 6 х Page 3 of 18 CIVL 317 p=001, p = 1036km) a = 10 m/sec and we

Answer 1

1. a) water demand/ consumption types

the water demand is the rate of water used in cities for day to day activities. there are different ways of water demand for the public utilities. there are many factors effecting water demand based on the water consumption. the water demanda are listed below.

1. domestic water demand
2. industrial water demand
3. institutional and commertial water demand
4. water demand for public use
5. fire water demand
6. loses and wastes

domestic water demand

thses water demand include the water required in houses for bathing, cooking, washing and gardening etc. the rate of water used is depends upon habits, social status and climatic conditions.

details for domestic consumption are given below:

• drinking -5 L
• cooking - 5L
• bathing - 75 L
• cloth washing - 25 L
• utensils washing - 15 L
• house washing - 15L
• flushing of water closets - 45 L
• for gardening - 15 L

So, total as per IS 1172- 1963 under normal condition, the domestic consuption of water in India is 135 to 200 liters/ day/ capita.

industrial water demand

these include water used for the working of indusrial purpose like paper mills, sugar cane induustries etc. these water demand varying with the type of industry. per capita consmption of industry is generally taken as 50 liter/ hour/ day. soem times in cities this may high as 450 liter/ capita/ day. the quantity of water demand is 20 to 25% of the total water demand.

institutional and commertial water demand

the rate of water used for colleges, schools, offices, hotels, hospitals, shopping centers and railway stations etc. are inclued in institutional and commertial water demand. average of institutional and commertial water demand is 20 liter/ hour/ day. and the maximum range is 50 liters/ capita/ day.

water demand for public use

the water used for cleaning of road and swers and garening of public park etc are included in water demand for public use. the rate of water used for water demand for public use is 5% of the total consuption. maximum 10liters/ capita/ day is used.

fire water demand

during fire brakedown large quantity of water is required. so more qantity of water is stored for this purpose. the water required in fire water demand is 100 P^1/2 , where P is the population in thousand.

loses and wastes

it include the breaking of pipe systems and losses due to continous wastage of water etc. the rate of loses and wastes is generally taken as 15% of the total water demand.

b) factors effecting water demand / consmption types

1. size of city / town : per capita water demand is large as compair to smoller towns.
2. industries and commercial activity : based on the numbers and type of industry and commercial building the water demend changes.
3. climatic condition : if the temperature increases water demand increases.
4. pressure in distribution system.
5. quality of water : if the water has good quality the water deamand increases.
6. system of supply.
7. cost of water : if cost increases water demand decteases
8. habit of people
9. public fecilities
10. method of charging

c) factors effecting head loss in water pipe systems

when water flowing through a pipe there may be some head loss in water. they may be classified as major head loss and minor loss. they are :

major loss

• frictional resistance loss : resistabce due to sher force between the particle and the pipe boundary resistance due to cohesion. and viscosity
• laminar flow and turbulant flow

minor loss

• due to sudden enlargement and contraction of pipe.
• at the entrance and exit of pipe.
• due to any obstuction to the flow.
• due to bend in pipe
• due to various pipe fitting

2. a) the type of flow is desied by knowing the renold's number R_e of a fluid.

for laminar flow .... R_e < 2000

unstable flow ......  2000 < R_e < 4000

turbulant flow ........... R_e > 4000

R_e is find out by using the formula

R_e = $\delta VD/\nu$

R_e - renold's number

$\delta$ -density of fluid

V - velocity

D - diameter of pipe

R_{e = 1008x3.6xx 0,05 / 103x10^-3}  = 1762.

R_e  < 2000

so the flow is laminar

b) head loss = f L V² / $\delta$ g

f - frictional loss

L - length

v - velocity

$\delta$ -density of fluid

g= 9.8 m/s²

head loss = 103 x10 ^-3 x 120 x 36 x36 /1008 x 9.8 = 1.62 m

total head loss = 1.62 m