Ce f312 first sem 13-14_pipe networks_evaluated assignment_ii

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Transcript of Ce f312 first sem 13-14_pipe networks_evaluated assignment_ii

Page 1: Ce f312 first sem 13-14_pipe networks_evaluated assignment_ii

Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE, Pilani

Pilani Campus

ASSIGNMENT SUBMISSION FORM

FIRST SEMESTER 2013-2014

COURSE NO.: CE F312 & COURSE TITLE: HYDRAULIC ENGINEERING

This form must be filled in and completed by the student submitting an assignment

of the above course. Assignments submitted without the completed form will not be

accepted.

Name:

ID No. :

Assignment No. and Title:

Submission Date:

I declare that this assignment, which I now submit for assessment, is entirely my own

work and has not been taken from the work of others. I understand that plagiarism,

collusion, and copying are grave and serious offences in our Institute and accept the

penalties that would be imposed should I engage in plagiarism, collusion or copying. This

assignment, or any part of it, has not been previously copied from any other person for

assessment on this or any other course of study.

Signature of student:_______________________________ Date: _________________

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE, PILANI

FIRST SEMESTER 2013-2014:

Course No.: CE F312 Hydraulic Engineering

Assignment II on Flow Analysis in Pipes

Last date of Submission: 10 October 2013 ---------------------------------------------------------------------------------------------------------------------

Note: (i) Attempt all questions.

(ii) Make necessary assumptions, if required.

(iii) Take ‘XXX’ = last 3 digits of your ID. No. in general if it is not

specified.

(iv) Assignment submission form must be filled in and completed by

the student submitting an assignment. (v) This assignment is to be submitted by each individual student registered

in this course. Please note that academic honesty and integrity are integral

part of your learning process which must be maintained by you

throughout the Semester. No type of academic malpractice is acceptable.

Copying or plagiarism of any form or extent is not allowed at all. You

must not copy your assignment from another student’s assignment. Any

such act will be considered to be a violation of the academic policy of

BITS Pilani and will invite disciplinary action. ---------------------------------------------------------------------------------------------------------------------

Q.1 For the pipe network given in Fig. Q.1, (a) determine the flow distribution in each

pipe with direction and (b) piezometric heads at the junctions using the Hardy

Cross method of solution. Assume that losses are proportional to Q2. If last three

numbers of your ID No. is between 0 and 100, take ‘XXX’ = last 3 numbers of

your ID. No. However if last three numbers of your ID No. lie between 340 and

570, assume ‘XXX’ = 0.20 times of last 3 numbers of your ID No. (c) Explain

under what circumstances is it required to provide a pump for this pipe network.

Also explain what kind of data is required if you need to install a pump in this

network. How would you analyze it if a pump is included in this network?

Please state any additional assumptions if required, and explain the solution

of the problem in your own words.

Figure Q.1

Q.2 A 60.0m long pipe with a diameter of 0.03m is used to circulate water at 25 °C

from a large tank through a filter and back to the tank as shown in Figure Q.2.

The power added to the water by the pump is 270 N. m/sec. Determine the flow

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

rate through the filter. Take ɛ/D = 0.01 for the pipe and dynamic viscosity of fluid

= 1.12 x 10-3

N.Sec/m2

where ɛ = average height of protrusions in the pipe. In

your solution, use all possibilities to determine the Darcy friction factor (f). What

type of fluid flow problem is it? Use the most suitable relation, and compare

the results from each method. What is the most accurate method and why?

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer. (You may consider power added to the water

by the pump pp ρgQhW =& ).

Figure Q.2

Q.3 Pipes 1 and 2 connect reservoir 1 [water level (W.L.) = 90.00 m which is working

like a sump], and reservoir 2 (W.L. = 100.00 m), respectively, to a junction point

J as shown in Fig. below. A third pipe, pipe 3, starts from the junction point J and

discharges into the atmosphere at point 3. A pump is also fitted in pipe 1 as shown

in the figure, characteristics curve of which may be obtained by considering

typical discharge-head data-0.0 m3/s: 18.0m, 0.1 m

3/s: 16.5 m, 0.2 m

3/s: 14.7 m,

0.3 m3/s: 11.9 m, and 0.4 m

3/s: 8.0 m (You may develop the corresponding head-

discharge curve or the corresponding discharge-head curve MS Excel). It is seen

that both curves are concave. The length, diameter and CH-W coefficient values of

the pipes are: Pipe 1 – 300 m, 300 mm, 100; pipe 2 – 250 m, 200 mm, 130; and

pipe 3 – 120 m, 300 mm, 100. Determine the discharges in pipes 1 and 2 and the

hydraulic gradient level (HGL) values at points J and 3, when the outflow at point

3 is 0.XXX m3/s where XXX is last 3 numerical digits of your ID. No. For the

pipe diameter in millimeters (D), pipe length in meters (L) and discharge in m3/s,

the resistance constant for a pipe may calculated using 4.871.852

WH

15

pipeDC

L104.351 R

×

××=

and

1.852f RQh = .

Figure Q.3

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer. Q.4 A certain part of cast iron piping of a water distribution system involves a parallel

section. Both parallel pipes have a diameter of 30 cm, and the flow is fully

turbulent. One of the branches (pipe A) is 1000 m long while the other branch

(pipe B) is 3000 m long. If the flow rate through pipe A is 0.4 m3/s, determine the

flow rate through pipe B. Disregard minor losses and assume the water

temperature to be 150C. Show that the flow is fully turbulent, and thus the friction

factor is independent of Reynolds number. Assume that the density and dynamic

viscosity of water at 15°C are ρ = 999.1 kg/m3

and µ =1.138×10-3

kg/m·s. The

roughness of cast iron pipe is k = 0.00026 m.

Figure Q.4

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer.

Q.5 Water from a treatment plant is pumped into a distribution system at a rate of 4.38

m3/s, a pressure of 480 kPa, and a temperature of 20

0C. The diameter of the pipe

is 750 mm and is made of ductile iron with the equivalent sand roughness of

ductile iron (= 0.26 mm). Estimate the pressure xxx m downstream of the

treatment plant if the pipeline remains horizontal. After 20 years in operation,

scale buildup is expected to cause the equivalent sand roughness of the pipe to

increase by a factor of 10. Determine the effect on the water pressure ‘xxx’ m

downstream of the treatment plant.

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer. Q.6 Consider a problem where discharge is unknown. A fire protection system is

supplied from a water tower and standpipe which is 25.0 m tall. The longest pipe

in the system is ‘xxx’ m where ‘xxx’ is last 3 digits of your ID. No. and is made

of cast iron about 20 years old. The pipe contains one gate valve; other minor

losses may be neglected. The pipe diameter is 10 cm. Determine the maximum

rate of flow through this pipe. You may assume that minor loss for a fully open

gate valve hLm = D g 2

VL f 2

e ; where equivalent length parameter 8 D

L e= when gate

is fully open. To be conservative, also assume that the standpipe is having the

same diameter as the horizontal pipe. Take kinematic viscosity of water -610 x 1.124 =ν m

2/sec and use Table 14.1 if it is necessary.

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer. Q.7 Please refer a paper on “Graph-Theoretical Models for Pipe Network Analysis”

by H. K. Kesavan, and M. Chandrashekar in ASCE Journal of Hydraulics

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

Division, Vol. 98, No. Hy2, pp. 345-364, February 1972. In this paper Graph-

theoretic models were developed for the analysis of nonlinear pipe networks. Both

symbolic formulation procedures as well as illustrative examples were presented.

The topological information contained in the continuity equations together with

the component characteristics are used to derive the minimum set of independent

equations in a systematic manner. In contrast to conventional methods, the

nonlinearities associated with components in the network are treated as an integral

part of the formulation procedures and thus they do not require any special

treatment. One of the main advantages of the graph-theoretic approach is that the

formulation procedure is independent of the numerical technique used to solve the

resulting set of nonlinear equations. In other words, once the equations are

formulated, a suitable numerical method for solution can be chosen. The graph-

theoretic formulation procedures are highly computer worthy.

Analyze the pipe network given below using Graph-theoretic models as discussed

in the above paper by taking all input data same as given in the paper except Qin

and Qout. Compare the results with Hardy Cross method. What are your findings?

Discuss point wise. (This is not included in Mid-Semester Test)

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer. Q.8 Suppose a new water supply lines are to be laid in BITS campus. Fig. below

shows the various zones of the campus and the fictitious population in each zone.

The pipe-lines are to be laid in dead end type. The average requirement of the

town is 175 liters/day/capita. Design the sizes of the distribution pipes AB, BC,

CD and DE with the following data and using Nomograph for Hazen-William’s

formula for C=100:

(i) Take the population for design as given in the Figure.

(ii) The reduced level of the bottom of the service reservoir (Over Head Tank) is

185.5 m and assume that OHT is very near to Point A.

(iii)The reduced level of the pipe points on the main road are: at A 168.0m, at B

154.0 m, at C 146.0 m, at D 146 m and at E is 140.0 m.

(iv) The assumed length of pipe AB is 700 m, pipe BC is 500 m, pipe CD is 800

m, and that of DE is 1000 m.

(v) The distribution system should be designed for a maximum demand of 3 times

the average demand.

(vi) The minimum pressure head to be maintained at any point in the distribution

system should be 15.0 m.

In your submission, state your assumptions and show all analysis procedures.

Comment on your final answer.

Qin = xxx, in m3/sec Qout2 = 75% of xxx, in m

3/sec

Qout1 = 25% of xxx, in m3/sec

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering

-----End of Assignment II-----

2500

SQ

TE

OHT

500

250

250

100

200

500

250

250

200

250

250

200

200

50

150

200

250

250

100

1000

200

900

450

Gym

MC

Coop

SK

VY

BET

BBV

BSV

MB

SQ

AK

RP

UCO

PO

BG

VK

WS

FDI

Lib

GN

KR

FDII

BD

RM

FDIII

SL

ML, MLE &

SAC

A B C D E

200

200

100

50

50

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Evaluative Assignment Sheet II on Flow Analysis in Pipes CE F312: Hydraulic Engineering