Armfield C4-MKII User manual

An ISO 9001 Company
INSTRUCTION MANUAL
C4-MKII
ISSUE 7
SEPTEMBER 2006
MULTI-PURPOSE TEACHING FLUME

IMPORTANT SAFETY INFORMATION
All practical work areas and laboratories should be covered by local safety regulations which
must be followed at all times.
It is the responsibility of the owner to ensure that all users are made aware of relevant local
regulations, and that the apparatus is operated in accordance with those regulations. If requested
then Armfield can supply a typical set of standard laboratory safety rules, but these are guidelines
only and should be modified as required. Supervision of users should be provided whenever
appropriate.
Your Multi-Purpose Teaching Flume has been designed to be safe in use when installed,
operated and maintained in accordance with the instructions in this manual and with the
instructions in the product manual supplied with the F1-10 Hydraulics Bench. As with any piece
of sophisticated equipment, dangers may exist if the equipment is misused, mishandled or badly
maintained.
Electrical Safety
The equipment described in this Instruction Manual operates using a service unit (the F1-10
Hydraulics Bench) that is powered by a mains voltage electrical supply.
•The flume involves the use of water so any supply must be properly protected to
minimise the possibility of electric shock.
•The F1-10 Hydraulics Bench must be operated as described in the F1-10 product manual,
and must be tested regularly to ensure that the integral electrical protection is working
correctly.
Wet Environment
Use of the flume requires the presence of fast-moving water. During use it is probable that there
will be some spillage and splashing.
•All users should be made aware that they may be splashed while operating the equipment,
and should wear appropriate clothing and non-slip footwear.
•‘Wet Floor’ warnings should be displayed where appropriate.
•Electrical devices in the vicinity of the flume must be suitable for use in wet
environments or be properly protected from wetting.

Moving or Rotating Components
The C4-MKII Multi Purpose Teaching Flume has moving components.
•Before operating the jacking system ensure that no person or object can become trapped
by the movement of the flume or the jacking mechanism.
The C4-67 Wave Generator has moving and rotating components.
•Ensure that the Wave Generator has been securely fixed to the top of the inlet tank on the
flume before connecting the electrical supply.
•Do not remove any protective guards while the Wave Generator is in operation or
connected to the electrical supply.
•When operating the apparatus ensure that long hair is tied back out of the way, and that
clothing and jewellery cannot come into contact with any moving parts. Dangling items
such as necklaces or neckties must be removed or secured so that they cannot become
entangled in the equipment.
•Do not touch any moving components while the Wave Generator is in use, or insert any
item into any moving or rotating section of the equipment.
•Ensure that the apparatus is switched off and disconnected from the electrical supply
before handling the equipment or making adjustments to the stroke adjuster.
Heavy Equipment
This apparatus is heavy.
•The apparatus should be placed in a location that is sufficiently strong to support its
weight, as described in the Installation section of the manual.
•The support pedestals may be bolted to the floor for additional stability.
•The flume should be assembled in place whenever possible. Where manual lifting is
necessary, two or more people will be required for safety. All should be made aware of
safe lifting techniques to avoid injury.
•Safety shoes and/or gloves should be worn when appropriate when moving the
equipment.
•If the apparatus is to be repositioned after installation, the apparatus must be drained
before it is moved and should be disassembled if possible.

Water Borne Hazards
The equipment described in this instruction manual involves the use of water, which under
certain conditions can create a health hazard due to infection by harmful micro-organisms.
For example, the microscopic bacterium called Legionella pneumophila will feed on any scale,
rust, algae or sludge in water and will breed rapidly if the temperature of water is between 20 and
45°C. Any water containing this bacterium which is sprayed or splashed creating air-borne
droplets can produce a form of pneumonia called Legionnaires Disease which is potentially fatal.
Legionella is not the only harmful micro-organism which can infect water, but it serves as a
useful example of the need for cleanliness.
Under the COSHH regulations, the following precautions must be observed:-
•Any water contained within the product must not be allowed to stagnate, i.e. the water
must be changed regularly.
•Any rust, sludge, scale or algae on which micro-organisms can feed must be removed
regularly, i.e. the equipment must be cleaned regularly.
•Where practicable the water should be maintained at a temperature below 20°C. If this is
not practicable then the water should be disinfected if it is safe and appropriate to do so.
Note that other hazards may exist in the handling of biocides used to disinfect the water.
•A scheme should be prepared for preventing or controlling the risk incorporating all of
the actions listed above.
Further details on preventing infection are contained in the publication “The Control of
Legionellosis including Legionnaires Disease” - Health and Safety Series booklet HS (G) 70.

MULTI-PURPOSE TEACHING FLUME
C4-MKII
Contents
1Introduction to the Equipment ......................................................................................................................... 7
1.1 Diagram 1: Inlet End of Flume .................................................................................................................. 8
1.2 Diagram 2: Discharge End of Flume......................................................................................................... 9
2Description........................................................................................................................................................ 10
2.1 Overview .................................................................................................................................................. 10
2.2 Working Section ....................................................................................................................................... 10
2.3 Inlet Tank ................................................................................................................................................. 10
2.4 Overshot Weir .......................................................................................................................................... 10
2.5 Optional Flowmeter ................................................................................................................................. 10
2.6 Hook and Point Gauges ........................................................................................................................... 11
2.7 Pedestals and Jack ................................................................................................................................... 11
2.8 The F1-10 Hydraulics Bench ................................................................................................................... 11
3Operation.......................................................................................................................................................... 13
3.1 Positioning the F1-10 Hydraulics Bench ................................................................................................. 13
3.2 Connecting the F1-10 Hydraulics Bench................................................................................................. 13
3.3 Filling the F1-10 Hydraulics Bench with water....................................................................................... 14
3.4 Assembling and Installing Models ...........................................................................................................14
3.5 Assembling and Installing the Venturi Flume .......................................................................................... 15
3.6 Installing the Optional False Floor Sections ........................................................................................... 15
3.7 Installing the Optional Roughened Bed Sections..................................................................................... 16
3.8 Sealing models into the flume................................................................................................................... 16
3.9 Use of Stop Logs to Vary Flume Flow Depth........................................................................................... 16
3.10 Installing the Optional Pitot Tube and Manometer Board (C4-61) ......................................................... 17
3.11 Operating the Optional Pitot Tube and Manometer (C4-61)................................................................... 18
3.12 Installing the Optional Wave Generator (C4-67)..................................................................................... 20
3.13 Operating the Optional Wave Generator (C4-67) ................................................................................... 20

4Specifications....................................................................................................................................................22
4.1 Overall Dimensions..................................................................................................................................22
4.2 Working Section Dimensions....................................................................................................................22
4.3 Flume Slope.............................................................................................................................................. 22
4.4 Flow Rate ................................................................................................................................................. 22
4.5 Electrical Supply ......................................................................................................................................23
4.6 Water Supply and Drain...........................................................................................................................23
4.7 Hook and Point Gauges (2 supplied) .......................................................................................................23
4.8 Models Available for Use in the C4-MkII Flume .....................................................................................23
5Routine Maintenance.......................................................................................................................................25
5.1 General..................................................................................................................................................... 25
5.2 RCD test for F1-10 Hydraulics Bench ..................................................................................................... 25
5.3 Test condition of water in F1-10 Hydraulics Bench.................................................................................25
5.4 Check C4-MkII for leaks ..........................................................................................................................25
5.5 Check condition of channel bed ............................................................................................................... 26
5.6 Full annual service...................................................................................................................................26
6Laboratory Teaching Exercises ......................................................................................................................29
6.1 Index to Exercises.....................................................................................................................................29
6.2 General Nomenclature .............................................................................................................................30
6.3 Nomenclature for Free Surface Flow.......................................................................................................31
6.4 Exercise A: Sharp Crested Overshot Weir ............................................................................................... 32
6.5 Exercise B: Broad Crested Weir ..............................................................................................................36
6.6 Exercise C: Crump Weir...........................................................................................................................40
6.7 Exercise D: Discharge Beneath a Sluice Gate.........................................................................................44
6.8 Exercise E: Force on a Sluice Gate .........................................................................................................48
6.9 Exercise F: The Specific Energy Equation...............................................................................................52
6.10 Exercise G: The Hydraulic Jump .............................................................................................................57
6.11 Exercise H: Flow Through a Venturi Flume ............................................................................................ 61
6.12 Exercise J: Flow Through a Culvert ........................................................................................................ 65
6.13 Exercise K: Flow Around Flow Splitters.................................................................................................. 68
6.14 Exercise L: Flow Over a Dam Spillway ...................................................................................................71
6.15 Exercise M: Flow Through a Siphon Spillway.........................................................................................74
6.16 Exercise N: Flow Through an Air Regulated Siphon ...............................................................................78
6.17 Exercise P: Flow Under a Radial Gate....................................................................................................84
6.18 Exercise Q: Flow Over False Floor Sections...........................................................................................87
6.19 Exercise R: Flow Over a Gravel Bed .......................................................................................................90
7Installation Guide................................................................................................................................................i

7
1 Introduction to the Equipment
When studying Hydraulics, the fundamental concepts of energy and momentum are sometimes
difficult to grasp, particularly where free surface flow is concerned. The Armfield Multi-Purpose
Teaching Flume has been developed to assist the student to overcome this difficulty. It provides a
basic but nonetheless comprehensive facility for student experiments in open channel flow.
Although small in comparison with the majority of flumes, the dimensions of the working
section have been sized so that the various phenomena may be clearly seen and reasonably
accurate results may be obtained from measurements taken.
The C4-MkII flume is supplied with either a 2.5 metre long working section or a 5.0 metre long
working section. Both versions of the flume can be fitted with an optional direct reading
flowmeter for convenience in operation. A set of basic models is included with all versions of the
flume. A range of optional models is also available to extend the experimental capabilities.
This manual covers all versions of the C4-MkII flume.
The flume requires the use of a standard Armfield Hydraulics Bench F1-10 (ordered
separately) which stores water for recirculation making the unit self contained, except for the
provision of an electrical supply. The construction of the flume allows for easy disassembly if at
a later date it is required to move the unit to a different location.
This manual includes experimental sheets detailing some of the demonstrations and exercises
which can be performed using the flume and models. We wish to emphasise that these
experiments do not exhaust the potential of the flume or the models. There are many further
investigations that an imaginative user can devise and the user can construct alternative models
for installation in the flume.
C4-MkII Multi-Purpose Teaching Flume
Shown with F1-10 Hydraulics Bench and optional flowmeter

8
1.1 Diagram 1: Inlet End of Flume
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