ENV3104 Hydraulics II XXXXXXXXXXAssignment 1
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Assignment 1
Gradually Varied Flow Profiles and Numerical Solution of
the Kinematic Equations
Examiner Marks out of Weighting (%) Due date
Kamrun Nahar XXXXXXXXXX14th April 2022
Objectives ✓ Evaluate and apply the equations available for the description of open
channel flow
✓ Solve the equations governing both steady and unsteady gradually
varied channel flow and apply them to the solution of practical flow
problems including: backwater profiles; runoff on a plane surface and
outing of a stream hydrograph; design erodible and vegetative lined
channels.
Rationale This assignment is based on the material covered in this course. As such
you will be directed to attempt tutorial questions from modules 1-5 before
starting the second question of this assignment.
Important
Information
Before starting please review the USQ’s Academic Integrity Policy and
Procedure:
“All assessable work in a course is to be the individual student’s own
work, unless advised otherwise in the Course Specification. It is
unacceptable for students to share solutions to assessable work on this
Study Desk site, or in any other manner. Violations of this principle are
egarded as Academic Misconduct and will be dealt with under the USQ
Academic Regulations."
For guidance on what constitutes Academic Misconduct and its various
categories, at USQ refer to the USQ Student Academic Misconduct Policy
available at: http:
policy.usq.edu.au/documents/13752PL
By submitting this assignment you hereby certify that:
The submission is entirely my own work except where due
acknowledgement is made in the text and that no part has been copied
from any other person’s work.
http:
policy.usq.edu.au/documents/13752PL
ENV3104 Hydraulics II XXXXXXXXXXAssignment 1
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Special
Instructions
✓ Spreadsheets or computer programs must be the work of the individual
student.
✓ Assignments submitted without adequate proof of program validation
will not be eligible for greater than a C grading.
✓ A proportion of the marks is allocated to the communication aspects of
the assignment. Marks will be deducted for untidy and poorly
presented work, poor English expression, and failure to cite sources of
information.
✓ Plagiarism is taken seriously in this course, as such your assignment
eport will be checked using Turnitin and your spreadsheets will be
checked thoroughly.
Instructions
for
Submission
Submission for this assignment is in two parts:
✓ Report introducing the problem, providing background in all
elevant theory, descriptions of methods and equations used and
discussion of results.
✓ Electronic copy of all computer code or spreadsheets used so the
examiner can validate the models.
The report should be compiled in such a manner that assessment can be
completed without access to the electronic copies of the code/spreadsheet
files. It is normal practice to include technical details (e.g. computer code)
as an appendix.
The assignment is to be submitted electronically via study desk. The link is
available on the course study desk.
Please note that hand written equations within the body of the report are
permitted. In many cases they are prefe
ed as they are simpler to produce
and easier to read than poorly set out computer produced equations.
Late
Submissions
If students submit assignments after the due date without (prior) approval
of the examiner then a penalty of 5% of the total marks gained by the
student for the assignment may apply for each working day late up to ten
working days at which time a mark of zero may be recorded. No
assignments will be accepted after feedback files have been posted
Assessment
Task
This assignment is comprised of two questions with the marks allocated as
follows
Question 1 – Gradually Varied Flow Profile 70 marks
Question 2 – Kinematic Wave Model 180 marks
ENV3104 Hydraulics II 2022 XXXXXXXXXXAssignment 1
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Question 1 – Gradually Varied Flow Profiles
The water flows in a triangular channel shown in Figure 1 with a side slope 1 (Hor.): 2.5 (Ver.)
and manning roughness coefficient of 0.04. The downstream end of this channel is a channel
of same cross section but of much higher slope. The sudden change in slope means that the
depth at the downstream end of the channel of interest can be approximated as critical depth.
Take alpha as being 1.1 (α=1.1).
The channel is conveying a steady flow rate of ? = (
1
0.2
+ 1.5 × ?1) m
3/s
The bed slope of the channel is ?? = (
1
1000
XXXXXXXXXX × ?2)
Where, ??is the second last digit and ?? is the last digit in your student number.
For example, if your student number is XXXXXXXXXXthen
? = (
1
0.2
+ 1.5 × 7) = 15.5 m3/s
?? = (
1
1000
XXXXXXXXXX × 5) = 0.0015
Figure 1: Long prismatic channel of triangular cross section
ENV3104 Hydraulics II 2022 XXXXXXXXXXAssignment 1
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Your task:
a) Use the direct step method, and the equation below to compute the water surface profile
upstream of the change in slope.
XXXXXXXXXXwhere
) Plot the water depth against distance.
c) Plot the longitudinal bed, normal depth, critical depth, water surface and energy line over
the length of this profile. (All on the same set of axis e.g. Fig 5.22 Chadwick, scanned copy of
this page in provided on study desk)
d) Include sample hand calculation in the report
Hints:
✓ The size of the step is up to you.
✓ Use of computers for this task (Excel, Matlab, etc is encouraged)
Marking Scheme for Question 1
Marks
✓ Initial Calculations
Initial calculations to classify the gradually varied
profile and help set up the direct step method
20
✓ Direct step Method The method implemented co
ectly 20
✓ Plots of profile Plots are shown co
ectly 20
✓ Sample Calculations
Showing sample calculation for at least one row
of the table
10
Total 70
0
2
1
f
R
S Sy
x F
−
=
−
R
V
F
g y
=
ENV3104 Hydraulics II 2022 XXXXXXXXXXAssignment 1
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Question 2 – Kinematic Wave Model
Background
You have been contracted to investigate the behaviour of a large car park when subjected to
a short duration high intensity storm rainfall event. As a first step you have decided to develop
a computer simulation of the water depths and flow rates when subjected to a specified
ainfall pattern. After making some reasonable assumptions you have decided that the
kinematic wave approximation is sufficient for this task
The Car Park
For study purposes it has been deemed sufficient to represent the behaviour of the car park
with a one-dimensional hydraulic model, in effect reducing the two-dimensional car park to
a unit flow width running down the predominant slope direction.
The specifications are as follows:
The length of the carpark area is determined by the last digit of your student number:
? = XXXXXXXXXX × ?????)
For example, if your student number was XXXXXXXXXX
? = XXXXXXXXXX × 5) = 145 m
Manning’s n = based on your research (assume a constant value of Manning’s roughness n
across the carpark. You should justify your choice)
Field Slope = Drop of 0.12 m over length L
Freely draining at downstream end.
ENV3104 Hydraulics II 2022 XXXXXXXXXXAssignment 1
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The design inflow
The model will be used to investigate the behaviour of the field when subjected to an
extreme rainfall event. An example of such event is given below in Figure 2.
Figure 2 – Example of Rainfall Hyetograph
Note: For simplicity it will be assumed that the car