F1-17 Issue 8 Orifice Free Jet Instruction Manual

Orifice Orific e & Free Free Jet Jet Flow

Instruction Manual F1-17 ISSUE 8 November 20 2013 13

Table Table of Contents Copyright and Trademarks............................ Trademarks ............................ .............................. ............................ 1 General Overview ............................. ............................. .............................. ............... 2 Equipment Diagrams........................................ ............................. .............................. 3 Important Safety Information..................... .............................. ............................. ....... 4 Introduction............................. ............................. .............................. ...................... 4 Electrical Safety............. ............................. .............................. ............................. .. 4 Description ............................ ............................. .............................. ........................... 5 Overview....................................... .............................. ............................. ................ 5 Installation................................ Installation.. .............................. ............................. .............................. ........................ 6 Advisory.................................................. Advisory..................... ............................. .............................. ............................. ...... 6 Installing the Equipment and Commissioning..................... Commissioning..................... ............................. ........ 6 Operation ........................... .............................. ............................. .............................. 7 Operating the Equipment............................................... ............................. ............. 7 Equipment Specifications. Specifications.............................. ............................. .............................. ............................. ... 8 Environmental Environmental Conditions............................................. .............................. ............. 8 Routine Maintenance ........................... .............................. ............................. ............ 9 Responsibility Responsibility ........................... .............................. ............................. .................... 9 General................................................... General...................... ............................. .............................. ............................. ...... 9 Laboratory Teaching Exercises........................................... ............................. ......... 10 Index to Exercises .......................... ............................. .............................. ............ 10 Nomenclature Exercise A .......................... .............................. ............................. . 10 Nomenclature Exercise B .......................... .............................. ............................. . 11 Nomenclature Exercise C .......................... .............................. ............................. . 11 Technical Data.................................. ............................ ............................ ............. 12 Exercise A - Determination of Coefficient Of Velocity From Jet Trajectory............... 13 Exercise B - Determination Determination of Coefficient of Discharge Under Constant Constant Head ........ 16 Exercise C - Determination Determination of Coefficient Of Discharge Discharge Under Varying Varying Head.......... 19 Operating the Optional Software (F1-301).......................... (F1-301) .......................... ............................. ......... 21 Contact Details for Further Information.......................... Information .......................... .............................. ............. 28 ii

Table Table of Contents Copyright and Trademarks............................ Trademarks ............................ .............................. ............................ 1 General Overview ............................. ............................. .............................. ............... 2 Equipment Diagrams........................................ ............................. .............................. 3 Important Safety Information..................... .............................. ............................. ....... 4 Introduction............................. ............................. .............................. ...................... 4 Electrical Safety............. ............................. .............................. ............................. .. 4 Description ............................ ............................. .............................. ........................... 5 Overview....................................... .............................. ............................. ................ 5 Installation................................ Installation.. .............................. ............................. .............................. ........................ 6 Advisory.................................................. Advisory..................... ............................. .............................. ............................. ...... 6 Installing the Equipment and Commissioning..................... Commissioning..................... ............................. ........ 6 Operation ........................... .............................. ............................. .............................. 7 Operating the Equipment............................................... ............................. ............. 7 Equipment Specifications. Specifications.............................. ............................. .............................. ............................. ... 8 Environmental Environmental Conditions............................................. .............................. ............. 8 Routine Maintenance ........................... .............................. ............................. ............ 9 Responsibility Responsibility ........................... .............................. ............................. .................... 9 General................................................... General...................... ............................. .............................. ............................. ...... 9 Laboratory Teaching Exercises........................................... ............................. ......... 10 Index to Exercises .......................... ............................. .............................. ............ 10 Nomenclature Exercise A .......................... .............................. ............................. . 10 Nomenclature Exercise B .......................... .............................. ............................. . 11 Nomenclature Exercise C .......................... .............................. ............................. . 11 Technical Data.................................. ............................ ............................ ............. 12 Exercise A - Determination of Coefficient Of Velocity From Jet Trajectory............... 13 Exercise B - Determination Determination of Coefficient of Discharge Under Constant Constant Head ........ 16 Exercise C - Determination Determination of Coefficient Of Discharge Discharge Under Varying Varying Head.......... 19 Operating the Optional Software (F1-301).......................... (F1-301) .......................... ............................. ......... 21 Contact Details for Further Information.......................... Information .......................... .............................. ............. 28 ii

Disclaimer This document and all the information contained contained within it is proprietary to Armfield Limited. This document must not be used for any purpose other than that for which it is supplied and its contents must not be reproduced, modified, adapted, published, translated or disclosed to any third party, in whole or in part, without the prior written permission of Armfield Limited. Should you have any queries or comments, please contact the Armfield Customer Support helpdesk (Monday to Thursday: 0830 – 1730 and Friday: 0830 - 1300 UK time). Contact details are as follows: United Kingdom

International

(0) 1425 478781 (calls charged at local rate)

+44 (0) 1425 478781 (international rates apply)

Email: [email protected] [email protected] Fax: +44 (0) 1425 470916

Copyrigh t and Trademarks Trademarks Copyright © 2013 Armfield Armfield Limited. Limited. All rights reserved. reserved. Any technical documentation documentation made made available available by Armfield Limited Limited is the copyright copyright work of Armfield Limited and wholly owned by Armfield Limited. Brands and product names mentioned in this manual may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.

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General Overview Fluid mechanics has developed as an analytical discipline from the application of the classical laws of statics, dynamics and thermodynamics, to situations in which fluids can be treated as continuous media. The particular laws involved are those of the conservation of mass, energy and momentum and, in each application, these laws may be simplified in an attempt to describe quantitatively the behaviour of the fluid. The hydraulics bench service module, F1-10, provides the necessary facilities to support a comprehensive range of hydraulic models each of which is designed to demonstrate a particular aspect of hydraulic theory. The specific hydraulic model that we are concerned with for this experiment is the Orifice and Jet Apparatus, F1-17. This consists of a reservoir of water with an orifice plate set into it. A jet of water issues from this hole and its trajectory may be measured using a set of needles. A full description of the apparatus is given later in these texts.

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Equipment Diagrams

Figure 1: F1-17 Orific e and Free Jet Flow Ap paratus

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Important Safety Inform ation Introduction Before proceeding to operate the equipment described in this text we wish to alert you to potential hazards so that they may be avoided. Although designed for safe operation, any laboratory equipment may involve processes or procedures which are potentially hazardous. The major potential hazards associated with this particular equipment are listed below. 

Injury through misuse



Injury from electric shock



Damage to clothing



Risk of infection due to lack of cleanliness

Ac ci dents can be avoi ded provided that equipment is regularly maint ained and staff and students are made aware of potential hazards list of general safety rules is included in the F1 Product Manual to assist staff and students in this regard. The list is not intended to be fully comprehensive but for guidance only. Please refer to the notes in the F1 Product Manual regarding the Control of Substances Hazardous to Health Regulations.

Electrical Safety The F1-10 Service Bench operates from a mains voltage electrical supply. The equipment is designed and manufactured in accordance with appropriate regulations relating to the use of electricity. Similarly, it is assumed that regulations applying to the operation of electrical equipment are observed by the end user. However, to give increased operator protection, Armfield Ltd have incorporated a Residual Current Device (RCD, alternatively called an Earth Leakage Circuit Breaker or ELCB) as an integral part of the service bench. If through misuse or accident the equipment becomes electrically dangerous, an RCD will switch off the electrical supply and reduce the severity of any electric shock received by an operator to a level which, under normal circumstances, will not cause injury to that person. Check that the RCD is operating correctly by pressing the TEST button. The circuit breaker MUST trip when the button is pressed. Failure to trip means that the operator is not protected and the equipment must be checked and repaired by a competent electrician before it is used.

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Description Where necessary, refer to the drawings in the Equipment Diagrams section.

Overview The rig is designed to be positioned on the side channels of the hydraulics bench top channel. The inlet pipe should be connected to the bench supply. An adjustable overflow pipe is provided adjacent to the header tank to allow changes in the head. A flexible hose attached to the overflow pipe returns excess water to t he sump tank. A scale indicates the water level. Finally a baffle at the base of the tank promotes smooth conditions prior to the orifice plates. Two orifice plates of differing diameters are provided and may be interchanged by slackening the two thumb nuts. The orifice plate is sealed against an ‘O’-ring by means of a special fitting which gives a flush inside surface. The trajectory of the jet may be plotted using the vertical needles. In operation, a piece of paper is attached to the backboard, and the needles are adjusted to follow the profile of the water jet. The needles may be locked using a screw on the mounting bar. The profile may be plotted by marking the position of the needle top. A drain plug in the base of the header tank allows water to be drained from the equipment after use into the channel of the F1-10.

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Installation Adv is or y Before operating the equipment, it must be unpacked, assembled and installed as described in the steps that follow. Safe use of the equipment depends on following the correct installation procedure.

Installing the Equipment and Commissioning The Orifice and Free Jet Flow apparatus is supplied ready for use and only requires setting up and connection to the F1-10 Hydraulics Bench as follows: Carefully remove the components from the cardboard packaging. Retain the packaging for future use. Wash each of the orifices and the inside of the t ransparent acrylic tank with warm water to which a few drops of wetting agent have been added. Locate the apparatus over the moulded channel in the top of the bench. Using the spirit level attached to the base, level the apparatus by adjusting the feet. Connect the flexible inlet tube on the side of the transparent header tank to the quick release fitting in the bed of the channel. Place the free end of the flexible tube from the adjustable overflow on the side of the header tank in to the volumetric tank (the volumetric tank will not be used for flow measurements). Make sure that this tube will not interfere with the trajectory of the jet flowing from the orifice Position the adjustable overflow tube at mid height and tighten the locknut. Secure each needle in the raised position by tightening the knurled screw. Attach the large spring clamp supplied to the top of the back plate. This clamp is used to secure a sheet of paper when plotting the trajectory of a jet using the needles. Install one of the two orifices in the fitting at the right hand side of t he header tank using the two securing screws supplied. Ensure that the 'O' ring seal is fitted between the orifice and the tank. Close the bench flow control valve, switch on the service pump then gradually open the bench flow control valve. When the water level in the header tank reaches the top of the overflow tube, adjust the bench flow control valve to give a water level of 2 to 3mm above the overflow level. This will ensure a constant head and produce a steady flow through the orifice. If necessary adjust the frame so that the row of needles are parallel with the jet but located just behind it by 1 or 2mm. This will avoid disturbing the jet but minimise errors due to parallax. The volume flowrate through the orifice can be determined by intercepting the jet using the measuring cylinder supplied in conjunction with a stopwatch (not supplied). The F1-17 Orifice and Free Jet Flow apparatus is ready for use. 6

Operation Where necessary, refer to the drawings in the Equipment Diagrams section.

Operating the Equipment See Laboratory Teaching Exercises for details on operating the equipment.

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Equipment Specifi cations Environmental Conditions This equipment has been designed for operation in the following environmental conditions. Operation outside of these conditions may result reduced performance, damage to the equipment or hazard to the operator. a. Indoor use; b. Altitude up to 2000m; c. Temperature 5°C to 40°C; d. Maximum relative humidity 80% for temperatures up to 31°C, decreasing linearly to 50% relative humidity at 40°C; e. Mains supply voltage fluctuations up to ±10% of the nominal voltage; f.

Transient over-voltages typically present on the MAINS supply; Note: The normal level of transient over-voltages is impulse withstand (overvoltage) category II of IEC 60364-4-443;

g. Pollution degree 2. Normally only nonconductive pollution occurs. Temporary conductivity caused by condensation is to be expected. Typical of an office or laboratory environment.

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Routine Maint enance Responsibility To preserve the life and efficient operation of the equipment it is important that the equipment is properly maintained. Regular maintenance of the equipment is the responsibility of the end user and must be performed by qualified personnel who understand the operation of the equipment.

General Little maintenance is required but it is important to drain all water from the header tank and associated pipework when not in use. A drain plug in the base of the reservoir allows water to be drained into the channel of the F1-10. The orifice plates should be dried before being stored. The apparatus should be stored where protected from damage. Following storage, wash each of the orifices and the inside surface of the clear acrylic tank with warm water to which a few drops of wetting agent have been added, before using the apparatus. This will remove any dirt or grease adhering to the surfaces and improve the accuracy of readings obtained using the apparatus.

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Laboratory Teaching Exercises Index to Exercises Exercise A - Determination of Coefficient Of Velocity From Jet Trajectory Exercise B - Determination of Coefficient of Discharge Under Constant Head Exercise C - Determination of Coefficient Of Discharge Under Varying Head

Nomenclature Exercis e A

Name

Unit Symbol Type

Definition

Orifice Diameter m

d

Orifice diameter. The diameter is Measured measured in mm. Convert to metres for the calculation.

Head

m

h

Measured

Horizontal Distance

m

x

Measured

Vertical Distance m

y

Measured

(yh)0.5

m

Calculated

Head in reservoir for which trajectory data has been taken. The head is entered in mm. Convert to metres for the calculation. Distance from the orifice of the measuring needle. The value is entered in mm. Convert to metres for the calculation. Distance the jet has fallen from the level of the orifice. The value is entered in mm. Convert to metres for the calculation. Allows the plotting of a straight line relationship between coefficient of velocity Cv and the horizontal distance for the jet. A graph of x plotted against will have a slope of 2C v

Slope Velocity Coefficient Cv

S

Calculated Slope of x vs

for each point.

Calculated

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Laboratory Teaching Exercises

Nomenclature Exercis e B

Name

Unit Symbol Type

Definition

Orifice diameter. The diameter is Measured measured in mm. Convert to metres for the calculation.

Orifice Diameter

m

d

Head

m

h

Measured Head in reservoir for which trajectory data has been taken. The head is entered in mm. Convert to metres for the calculation.

Volume

m3

V

Measured

Time

s

t

Measured

Flowrate

m3/s Qt

Taken from scale on hydraulics bench. The volume collected is measured in litres. Convert to cubic metres for the calculations (divide reading by 1000) Time taken to collect the known volume of water

Calculated Allows the plotting of a straight line Calculated relationship between coeffecient of velocity, Cv, and the flowrate for the jet, Q t

0.5

(h)

Slope

S

Calculated Slope of flow rate vs.

Discharge Coefficient Cd

Cd

Calculated

for each point.

Nomenclature Exercise C

Name

Unit Symbol Type

Definition

Orifice Diameter m

d

Measured Orifice diameter. The diameter is measured in mm. Convert to metres for the calculation.

Area of Orifice

Ao

Calculated

m²

Orifice area, calculated from the orifice diameter

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Armfield Instruction Manual

Area of Reservoir

m2

Ar

Given

Surface area of the reservoir including area of constant head tank. Ar = 1.832x10-2 m2

Head

m

h

Measured Head in reservoir at time t. The head is entered in mm. Convert to metres for the calculation

Head at Start

m

h1

Measured Head in reservoir at time t = 0. The head is entered in mm. Convert to metres for the calculation

Time

s

t

Measured Time since start of run Allows the plotting of a straight line Calculated relationship between coefficient of discharge, Cd, and the head loss.

0.5

h

Slope

S

Calculated Slope of t vs

Discharge Coefficient Cd

Cd

Calculated

for each point

Technic al Data The following dimensions from the equipment are used in the appropriate calculations. If required these values may be checked as part of the experimental procedure and replaced with your own measurements. Diameter of small orifice: 0.003m (3mm) Diameter of large orifice: 0.006m (6mm) Surface Area of Reservoir: A R = 1.832 x 10-2m2 Pitch of needles: 0.05m (50mm)

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Exercise A - Determin ation o f Coefficient Of Velocity From Jet Trajectory Objective To determine the coefficient of velocity of two small orifices.

Method By measurement of the trajectory of a jet issuing from an orifice in the side of a reservoir under steady flow conditions (constant reservoir head).

Equipment In order to complete the demonstration we need a number of pieces of equipment. 





The F1-10 Hydraulics Bench which allows us to measure flow by timed volume collection. The F1-17 Orifice and Jet Apparatus. A stopwatch to allow us to determine the flow rate of water (not supplied).

Equipm ent Set Up Position the reservoir across the channel on the top of the hydraulic bench and level the reservoir by the adjustable feet using a spirit level on the base. Remove the orifice plate by releasing the two knurled nuts and check the orifice diameter; take care not to lose the O-ring seal. Replace the orifice and connect the reservoir inflow tube to the bench flow connector. For accurate results measure the actual distance from the orifice plate to the first needle (nominal distance X 1 = 50mm). Position the overflow connecting tube so that it will discharge into the volumetric tank; make sure that this tube will not interfere with the trajectory of the jet flowing from the orifice. Turn on the pump and open the bench valve gradually. As the water level rises in the reservoir towards the top of the overflow tube, adjust the bench valve to give a water level of 2 to 3mm above the overflow level. This will ensure a constant head and produce a steady flow through the orifice.

Theory From the application of Bernoulli's Equation (conservation of mechanical energy for a steady, incompressible, frictionless flow): the ideal orifice outflow velocity at the jet vena contracta (narrowest diameter) is

where h is the height of fluid above the orifice.

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The actual velocity is

…. (1) Cv is the coefficient of velocity, which allows for the effects of viscosity and, therefore Cv < 1 Cv can be determined from the trajectory of the jet using the following argument: Neglecting the effect of air resistance, the horizontal component of the jet velocity can be assumed to remain constant so that in time, t, the horizontal distance travelled, X = vt

…. (2)

Because of the action of gravity, the fluid also acquires a downward vertical (ydirection) component of velocity. Hence, after the same time, t, (ie. after travelling a distance x) the jet will have a y displacement given by

which can be rearranged to give:

…. (3) Substitution for t from (3) into (2) and for v from (1) into (2) yields the result:

Hence, for steady flow conditions, ie. constant h, C v can be determined from the x, y co-ordinates of the jet. A graph of x plotted against

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will have a slope of 2C v

Exercise A

Procedure Position the overflow tube to give a high head. Note the value of the head. The jet trajectory is obtained by using the needles mounted on the vertical backboard to follow the profile of the jet. Release the securing screw for each needle in turn and move the needle until its point is just immediately above the jet and re-tighten the screw. Attach a sheet of paper to the back-board between the needle and board and secure it in place with the clamp provided so that its upper edge is horizontal. Mark the location of the top of each needle on the paper. Note the horizontal distance from the plane of the orifice (taken as x = 0) to the co-ordinate point marking the position of the first needle. This first co-ordinate point should be close enough to the orifice to treat it as having the value y = 0. Thus y displacements are measured relative to this position. Estimate the likely experimental errors in each of the quantities measured. Repeat this test for a low reservoir head. Then repeat the above procedure for the second orifice. Orifice Diameter d (m)

Head h (m)

Horizontal Distance

Vertical Distance

x

y

(m)

(m)

1

0.05

2

0.10

3

0.15

4

0.20

5

0.25

6

0.30

7

0.35

8

0.40

yh 0.5 (m)

9 10 11

Plot x vs

and determine the slope of the graph.

The velocity coefficient C v is equal to the average slope/2.

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Exercise B - Determin ation of Coeffi cient of Disc harge Under Const ant Head Objective To determine the coefficient of velocity of two small orifices.








Equipm ent Set Up Position the reservoir across the channel on the top of the hydraulic bench and level the reservoir by the adjustable feet using a spirit level on the base. Remove the orifice plate by releasing the two knurled nuts and check the orifice diameter; take care not to lose the O-ring seal. Replace the orifice and connect the reservoir inflow tube to the bench flow connector. Position the overflow connecting tube so that it will discharge into the volumetric tank; make sure that this tube will not interfere with the trajectory of the jet flowing from the orifice. Turn on the pump and open the bench valve gradually. As the water level rises in the reservoir towards the top of the overflow tube, adjust the bench valve to give a water level of 2 to 3mm above the overflow level. This will ensure a constant head and produce a steady flow through the orifice.

Theory From the application of Bernoulli's Equation (conservation of mechanical energy for a steady, incompressible, frictionless flow): the ideal orifice outflow velocity at the jet vena contracta (narrowest diameter) is

where h is the height of fluid above the orifice.

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Exercise B

The actual velocity is

…. (1) Cv is the coefficient of velocity, which allows for the effects of viscosity and, therefore Cv < 1 The actual flow rate of the jet is defined as: Qt = Acv where Ac is the cross-sectional area of the vena contracta, given by : Ac = Cc Ao where Ao is the orifice area and C c is the coefficient of contraction and, therefore, C c < 1 Hence

The product CcCv is called the discharge coefficient, C d , so finally

If Cd is assumed to be constant, then a graph of Q t plotted against

will be linear

and the slope,

Procedure Measure the flow rate by timed collection, using the measuring cylinder provided and note the reservoir head value. Repeat this procedure for different heads by adjusting the level of the overflow tube. The procedure should also be repeated for the second orifice.

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Orifice Diameter d (m)

Head

Volume

Time

Flowrate

h

V

t

Qt

h 0.5

(m)

(m 3)

(secs)

(m 3/sec)

(m 0.5)

1 2 3 4 5 6 7 8 9 10 11

Plot flowrate Qt vs


The coefficient of discharge C d can then be calculated from

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Exercise C - Determin ation o f Coeffici ent Of Disc harge Under Varyi ng Head Objective To determine the coefficient of velocity of two small orifices.








Equipm ent Set Up Position the reservoir across the channel on the top of the hydraulic bench and level the reservoir by the adjustable feet using a spirit level on the base. Remove the orifice plate by releasing the two knurled nuts and check the orifice diameter; take care not to lose the O-ring seal. Replace the orifice and connect the reservoir inflow tube to the bench flow connector. Position the overflow connecting tube so that it will discharge into the volumetric tank; make sure that this tube will not interfere with the trajectory of the jet flowing from the orifice. Turn on the pump and open the bench valve gradually. As the water level rises in the reservoir towards the top of the overflow tube, adjust the bench valve to give a water level of 2 to 3mm above the overflow level. This will ensure a constant head and produce a steady flow through the orifice.

Theory For unsteady flow, the time, t, for the head to drop from to is given by

where Ar is the cross-sectional area of the reservoir (including the secondary chamber). Note: This is an approximate result, which does not allow fully for the effects of flow unsteadiness.

Procedure For flow under a varying head, the overflow pipe is raised to obtain the maximum head, the header tank is filled to just below the top and the bench flow control valve closed and the pump stopped. Start a stopwatch when the level reaches the first convenient scale mark (noted as h1). You will need to take readings of the falling head (h) at 20 second intervals. You may find the easiest way of doing this is to 19

Armfield Instruction Manual attach a piece of masking tape immediately adjacent to the scale on the reservoir and at 20 second intervals mark the position of the falling level. At the end of this procedure, you can then read off the head position corresponding to the known time. The above procedure should be repeated using the second orifice. Orifice Diameter

Ar ea of Reservoir

d

A R

(m)

(m 2)

Head

Time

h

t

h 0.5

(m)

(sec)

(m 0.5)

1 2 3 4 5 6 7 8 9 10 11

Plot time t vs.


The coefficient of discharge C d can be calculated from

Conclusion Is it justifiable to assume that C d is a constant over the range of steady flows tested? Why are the Cd values significantly less than 1.0? Compare the C d values obtained for the constant and falling head tests. Which value is the more reliable result?

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Operating the Optional Software (F1-301) Note: The diagrams in this section are included as typical examples and may not relate specifically to an individual product. The Armfield Software is a powerful Educational and Data Logging tool with a wide range of features. Some of the major features are highlighted below, to assist users, but full details on the software and how to use it are provided in the presentations and Help text incorporated in the Software. Help on Using the Software or Using the Equipment is available by clicking the appropriate topic in the Help drop-down menu from the upper toolbar when operating the software as shown:

Load the software. If multiple experiments are available then a menu will be displayed listing the options. Wait for the presentation screen to open fully as shown:

Presentatio n Screen - Basics and Navig ation As stated above, the software starts with the Presentation Screen displayed. The user is met by a simple presentation which gives them an overview of the capabilities of the equipment and software and explains in simple terms how to navigate around the software and summarizes the major facilities complete with direct links to detailed context sensitive ‘help’ texts.

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Armfield Instruction Manual To view the presentations click Next or click the required topic in the left hand pane as appropriate. Click More while displaying any of the topics to display a Help index related to that topic. To return to the Presentation screen at any time click the View Presentation icon from the main tool bar or click Presentation from the dropdown menu as shown:

For more detailed information about the presentations refer to the Help available via the upper toolbar when operating the software.

Toolbar A toolbar is displayed at the top of the screen at all times, so users can jump immediately to the facility they require, as shown:

The upper menu expands as a dropdown menu when the cursor is placed over a name. The lower row of icons (standard for all Armfield Software) allows a particular function to be selected. To aid recognition, pop-up text names appear when the cursor is placed over the icon.

Mimic Diagram The Mimic Diagram is the most commonly used screen and gives a pictorial representation of the equipment, with boxes to enter measurements from the equipment, display any calculated variables etc. directly in engineering units. To view the Mimic Diagram click the View Diagram icon or click Diagram from the View drop-down menu as shown:

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from the main tool bar

Operating the Software A Mimic diagram is displayed, similar to the diagram as shown:

The details in the diagram will vary depending on the equipment chosen if multiple experiments are available. Manual data input boxes with a coloured background allow measured variables, constants such as Orifice Cd and Atmospheric Pressure, as appropriate, to be changed by over-typing the default value. After typing the value press the Return key or click on a different box to enter the value. In addition to measured variables such as Volume, Time, Temperature or Pressure, calculated data such as Discharge / Volume flowrate, Headloss etc are continuously displayed in data boxes with a white background. These are automatically updated and cannot be changed by the user. After entering a complete set of data from measurements on the equipment click on the

icon to save the set of results before entering another set.

The mimic diagram associated with some products includes the facility to select different experiments or different accessories, usually on the left hand side of the screen, as shown:

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Clicking on the appropriate accessory or exercise will change the associated mimic diagram, table, graphs etc to suit the exercise being performed.

Data Loggin g Facil iti es in the Mimi c Diagram Armfield software designed for manual entry of measured variables does not include automatic data logging facilities and these options are greyed out where not appropriate. When manually entering data the icon simply saves the set of entered data into a spreadsheet as described above.

Tabular Disp lay To view the Table screen click the View Table icon click Table from the View dropdown menu as shown:

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from the main tool bar or

Operating the Software The data is displayed in a tabular format, similar to the screen as shown:

As the data is sampled, it is stored in spreadsheet format, updated each time the data is sampled. The table also contains columns for the calculated values. New sheets can be added to the spreadsheet for different data runs by clicking the icon from the main toolbar. Sheets can be renamed by double clicking on the sheet name at the bottom left corner of the screen (initially Run 1, Run 2 etc) then entering the required name. For more detailed information about Data Logging and changing the settings within the software refer to the Help available via the upper toolbar when operating the software.

Graphical Display When several samples have been recorded, they can be viewed in graphical format.

To view the data in Graphical format click the View graph icon tool bar or click Graph from the View drop-down menu as shown:

from the main

25

Armfield Instruction Manual The results are displayed in a graphical format as shown:

(The actual graph displayed will depend on the product selected and the exercise that is being conducted, the data that has been logged and the parameter(s) that has been selected). Powerful and flexible graph plotting tools are available in the software, allowing the user full choice over what is displayed, including dual y axes, points or lines, displaying data from different runs, etc. Formatting and scaling is done automatically by default, but can be changed manually if required. To change the data displayed on the Graph click Graph Data from the Format dropdown menu as shown:

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Operating the Software The available parameters (Series of data) are displayed in the left hand pane as shown:

Two axes are available for plotting, allowing series with different scaling to be presented on the same x axis. To select a series for plotting, click the appropriate series in the left pane so that it is highlighted then click the appropriate right-facing arrow to move the series into one of the windows in the right hand pane. Multiple series with the same scaling can be plotted simultaneously by moving them all into the same window in the right pane. To remove a series from the graph, click the appropriate series in the right pane so that it is highlighted then click the appropriate left-facing arrow to move the series into the left pane. The X-Axis Content is chosen by default to suit the exercise. The content can be changed if appropriate by opening the drop down menu at the top of the window. The format of the graphs, scaling of the axes etc. can be changed if required by clicking Graph in the Format drop-down menu as shown:

For more detailed information about changing these settings refer to the Help available via the upper toolbar when operating the software.

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F1-17 Issue 8 Orifice Free Jet Instruction Manual

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