Hydraulics II Report 2 S1 2023 Final :

Examiner | Marks out of | Weighting (%) | Due date |

Kamrun Nahar | 250 | 25 | 8^{th} May 2023 |

Objectives | Evaluate and apply the equations available for the description and design of open channel flowsolve 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 routing of a stream hydrograph; design erodible and vegetative lined channels;Solve simple pipe networks using an appropriate methodapply rigid column theory to unsteady pipeline flow to analyse mass oscillations in pipelines and calculate maximum allowable rates for valve opening and closureDesign a range of hydraulic structures including: fixed and movable crest weirs; gated control structures; pipe conveyance structures; spillways and energy dissipation structure; critical flow measuring flumes; gulley control structures; weir and culvert type structures using the minimum specific energy concept. |

Rationale | This report is based on the material covered in this course. As such you will be directed to attempt tutorial questions from modules 8,10,15 before starting this assessment. |

Important Information | At UniSQ, Policy and Procedure guides our approach to assessment, and it is important that all students are familiar with the relevant Policy and Procedure documents and complete the Academic Integrity Mandatory Training every 12 months. 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. |

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 report will be checked using Turnitin and your spreadsheets (if you have chosen to use Excel or equivalent) will be checked for plagiarism |

Instructions for Submission | Submission for this assignment is in two parts: Report introducing the problem, providing background in all relevant theory, descriptions of methods and equations used, discussion of results and your reflection.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 preferred 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 report is comprised of three questions with the marks allocated as follows Question 1 – Pipe Network 100 marks Question 2 – Vegetative Lined Channels 60 marks Question 3 –Control Structure 70 marks |

#### Question 1 – Pipe Network (100 Marks)

A pipe network as shown in Figure 1 has been constructed in order to convey water from a reservoir A to a number of delivery points.

The details of each pipe are given in the table below. You may also neglect all minor losses that may occur in the system.

Pipe | AB | BC | CD | ED | EA | EF | FB | FC |

Length (m) | 300 | 400 | 200 | 320 | 325 | 120 | 150 | 160 |

Diameter (mm) | 250 | 200 | 150 | 150 | 250 | 180 | 180 | 150 |

Roughness (mm) | 0.05 | 0.07 | 0.09 | 0.15 | 0.05 | 0.2 | 0.2 | 0.25 |

**Figure 1 – Pipe network for Q1**

The head added by the pump (P) is a constant 20m. The pressure head elevation at point A is 78 m.

The elevation of each node of the pipe network is given below.

Node | A | B | C | D | E | F |

Elevation (m) | 30 | 30 | 35 | 30 | 30 | 30 |

#### Tasks:

- Use the
**linearisation method**to solve for the unknown discharges in each pipe of the network.

- Accounting for the elevation of each node, estimate the pressure head in metres at each pipe junction (A, B, C, D, E, F)

*HINT: **The pump has the opposite effect (opposite direction) to the friction loss in pipe BC*

**Marking Scheme: Question 1 – Pipe Network**

Items | Requirements | Marks |

Formulation of Equations | Diagram with assumed flow directionsContinuity (node) equationsenergy loop equationsCorrectly accounted for pump | 30 |

Method | Model uses the linearization methodModel is correctCalculates friction properlyAccounts for pump | 20 |

Solution for Q | Correct solution for the flows | 20 |

Calculation of Heads | Correct solution for the heads | 20 |

Discussion & Presentation | Solution processResults (including impact of pump)Following report format | 10 |

Total | 100 |

#### Question 2 – Vegetative Lined Channels (60 Marks)

Design the broad shallow grassed waterway for the transmission of flood flows in a compound channel illustrated below:

Design Data:

- The soil type is erosion resistant
- The channel is currently planted with Rhodes grass
- The Bed slope is 3%

The channel consists of:

- a narrow concrete lined section (n = 0.014) designed to carry the normal low streamflow; and
- a broad shallow grassed waterway for the transmission of flood flows. Your design must satisfy two main criteria:

The velocity of flow does not exceed the permissible velocity nominated for the particular

grass and soil in the waterway, that is, the channel must be stable.

The depth of flow does not exceed the height of the channel banks, that is, the channel must have sufficient capacity.

#### Marking Scheme: Question 2

Sections | Marks |

Preliminary Check | 15 |

Stability Check | 15 |

Capacity Check | 15 |

Report with all relevant information | 15 |

Total | 60 |

**Question 3 – Control Structure (70 marks)**

An irrigation scheme is fed from a river via a diversion channel. The irrigation channel is 2 m wide and is constructed of rough concrete with an estimated value of 0.025 for the Manning

n. The bed slope is 0.0025.

The discharge into the channel is controlled by a vertical sluice gate (Cc = 0.61). The depth upstream of the gate is a constant 3.0 m, and the maximum discharge is 7 m^{3} /s.

The designer of the gate has prepared a rating curve for the sluice gate (yg vs Q) for free- flowing conditions as shown below in the table.

The issue is that the designer has not considered those cases where the gate may be drowned by the hydraulic jump downstream of the gate. The depth on the downstream side of the gate is equal to the normal flow depth.

Independently you have determined the normal flow depths over the operating range of discharges, which is also included in the table below.

Q (m^{3}/s) | yg (Assuming free lowing (m) | yn or y3 (Normal flow downstream of hydraulics jump) (m) |

1 | 0.1080 | 0.5138 |

2 | 0.2181 | 0.8424 |

3 | 0.3309 | 1.1410 |

4 | 0.4463 | 1.4253 |

5 | 0.5638 | 1.7013 |

6 | 0.6839 | 1.9718 |

7 | 0.8067 | 2.2385 |

**Figure 2 – Gate rating curve assuming free flowing conditions**

#### Your Task:

- Determine at what discharge the gate changes from freely flowing to submerged conditions (to the nearest m
^{3}/s)? - Calculate the new gate opening (yg) for those discharges for where the gate is submerged by the depth downstream of the gate.
- Plot the new rating curve (alter the part where gate is submerged)

#### Marking Scheme Question 3 – Control Gate

Items | Requirements | Marks |

Equations and Diagram | Labelled diagramEquations are introduced | 10 |

Determining when gate is submerged | Apply the hydraulic jump equationValues at appropriate intervals of QPlot of h or y vs QSample hand calc | 30 |

New yg for submerged | Method is correctsample hand calc or explanation | 20 |

Rating Curve | Plotted the new curve with given yg | 10 |

Total | 70 |

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