FSAE FLOW TESTING DEVICE
ME493 Final Report
Spring 2012
Group Members
Adam Barka
Jasper Wong
Keith Lundquist
Long Dang
Vu Nguyen
Portland State University Advisor
Dr. Chien Wern
Industry Advisor
Evan Waymire
Executive Summary
Viking Motorsports (VMS) is a student organization at Portland State University that
participates in the Formula SAE student competition. To be more competitive, VMS
commissioned the PSU capstone team to design and manufacture a device to determine the flow
coefficients of their custom powertrain components by June 2012. Viking Motorsports has
defined a series of product design specifications outlining the device’s capacity, reliability, and
cost; the device will be able to test components up to 160 cfm at a test pressure of 28 inches of
water column, will be able to archive 95% repeatability, and will cost less than $1,500.
This team has designed, built, and tested a prototype device that meets all of the PDS
requirements except for the maximum capacity requirement. The device will meet this
requirement after a comprehensive leak test and fine-tuning.
VMS has approved the final product, which is currently available to for their use in the
VMS team lab. All future testing and modifications will be performed by both VMS and FSAE
Flow Testing Device team members.
Table of Contents
Executive Summary
Introduction and Background ............................................................................................................................................ 1
Mission Statement ................................................................................................................................................................... 2
Product Design Specifications ............................................................................................................................................ 2
Top-Level Design Alternatives ........................................................................................................................................... 3
Final Design Overview........................................................................................................................................................... 4
1.
2.
3.
Main Box ............................................................................................................................................................................ 5
1.1.
DUT Mount .............................................................................................................................................................. 5
1.2.
Metering Element ................................................................................................................................................. 6
1.3.
Ductwork ................................................................................................................................................................. 7
Air Box ................................................................................................................................................................................ 8
2.1.
Pump.......................................................................................................................................................................... 8
2.2.
Flow control ........................................................................................................................................................... 9
2.3.
Ductwork ............................................................................................................................................................... 10
Electrical system .......................................................................................................................................................... 11
3.1.
Measurement system........................................................................................................................................ 11
3.2.
Electrical circuit and Controls system ....................................................................................................... 12
3.3.
User Interface ...................................................................................................................................................... 14
Conclusion ................................................................................................................................................................................ 19
Appendix A: 2011 VMS Powertrain Components ........................................................................................................ i
Appendix B: Detailed Product Design Specifications............................................................................................... iv
Appendix C: Details on Alternative Designs ............................................................................................................... vii
Appendix D: Concept Selection Methodology ............................................................................................................. ix
Appendix E: Orifice Size Analysis..................................................................................................................................... xi
Appendix F: Main Chamber Sizing Analysis .............................................................................................................. xiv
Appendix G: Pump Size Analysis ................................................................................................................................... xvii
Appendix K: Bill of Materials .................................................................................................................................................
Appendix L: Project Plan .........................................................................................................................................................
Appendix M: User Manual .......................................................................................................................................................
Appendix N: Part Drawings ....................................................................................................................................................
Introduction and Background
Each year, the Society of Automotive Engineers (SAE) invites colleges from around the
world to participate in their Formula SAE series competition. This competition challenges
students from each school to design, build, and race an open-wheeled formula style race car.
Portland State is represented in this series by the Viking Motorsports (VMS) student group.
In order to encourage teams to focus on design and optimization rather than on generating
raw power, the SAE has imposed a series of regulations on the powertrain subsystem of the race
car. The most notable regulation is that all of the air supplied to the car’s engine must go through
a 20 mm restrictor, which severely limits the output power of the engine. In order to achieve
maximum power output, VMS must be able to accurately measure the mass flow of any
customized component (see Appendix A) at a standard pressure in order to reduce parasitic
losses to the engine. In addition, the team must measure the discharge or flow coefficient of the
cylinder intake and exhaust valves, as well as of the butterfly valve on the throttle. These values
are necessary for the team to utilize 1-D simulation software to improve their design. Currently,
VMS has no method to test for these values.
In order to flow test their components, the powertrain group could purchase a device
known as a flow bench. A typical flow bench uses a pump to move air through a device under
test (DUT) and then through a calibrated obstruction flow meter at a standard test pressure,
which is measured upstream of the flow meter. The pressure drop across the obstruction is a
known function of the volume flow rate through the meter. The mass flow rate through the DUT,
which is also known as the flow coefficient of the DUT, is calculated from the volume flow
across the meter and from temperature and pressure measurements at the DUT. Figure 1 shows a
typical flow bench operating under a pressure differential that is negative, relative to atmospheric
pressure. A flow bench would reverse the flow by creating a positive pressure differential
relative to atmospheric.
Figure 1. Simple flow bench. P1 is the test pressure; the difference P2-P1 is measured to produce mass flow rate.
Page | 1
There are many flow benches available for purchase, but all share similar limitations.
Foremost is cost. Commercial flow benches with enough air flow capacity to accurately test
VMS powertrain components cost anywhere from $5,000 to $15,000. In addition, commercial
devices would require VMS to build customized mounts to accommodate the restrictor, intake
manifold, and exhaust. Finally, commercial flow benches do not easily allow for future
improvements or modifications. VMS has constantly changing needs, and so must be able to
modify the testing device.
Mission Statement
This team is challenged to design and build a device capable of measuring the flow
coefficients for the engine head’s valves, and throttle valves of a formula SAE racecar at various
open positions, and to measure the mass flow through the racecar’s intake manifold and exhaust
ductwork. The device will measure these values at a standard test pressure of 28 inH20 with 95%
measurement repeatability. The completed project, consisting of a working prototype, testing
results, detailed drawings, a bill of material, and detailed reports, will be presented in June 2012.
If successful, the project will help the VMS team to validate and improve their designs.
Product Design Specifications
Product design specifications (PDS) define the customer’s needs in terms of engineering
metrics and criteria. The team has verified its progress throughout the design process using the
PDS provided by VMS. As the design evolved, some targets and metrics were re-evaluated to
provide the best representation of the customer’s needs. Appendix B includes a detailed list of
these requirements. VMS highlighted the following criteria as the most significant:
 Performance: The device must be able to pull and push 10 to 160 cfm of air with a
test pressure of 0 to 28 inH20.
 Repeatability: Experimental results must be repeatable within 95%.
 Geometry: The device must be compact enough to be stored in the capstone lab. The
device’s footprint must be no larger than 6 ft x 4 ft.
 Safety: The noise made by the device must be less than 95 dB, and there must be no
risk of electric shock.
 Maintenence: All parts must be easy to inspect and replace.
 Cost: The total cost of the device must be less than $1,500.
Page | 2
Top-Level Design Alternatives
To determine the best top-level design, the team brainstormed several top level concepts.
These were quickly narrowed down to three reasonable alternatives, which are summarized in
Appendix C. The first design, called the Basic design, focuses on meeting the most important
design criteria as inexpensively as possible by using an analog measurement system and simple
PVC pipe ductwork. The second design features large plenums instead of PVC in order to create
more stable measurements. It also moves to a digital data acquisition (DAQ) system. The third
design uses a hot wire manometer and an automatically controlled flow diverter to allow for fast
measurements and quicker turnaround between experiments. The team used a weighted scoring
matrix (Appendix D) to make an unbiased selection of the best option. The Balanced Design,
shown in figure 2, was selected as the final, top level design concept.
Figure 2. Balanced design, which was chosen by the weighted scoring matrix method as the best design.
In addition, it was determined that a majority of the points for Design 3 came from the
automated function. The team decided to include this function in their final design, since the
flow diverter can cheaply and easily be converted to an automated system. In addition, the team
decided to include the analog measurement devices from Design 1 to provide a check for the
digital devices and allow use of the device even if the software is not functioning.
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Final Design Overview
The Balanced Design was the design used for the production of the VMS flow bench. To
the initial Balanced Design, the team added an automatic bleed valve to control the test pressure,
as well as analog pressure and temperature meters to supplement the digital meters. The final
design breaks the top level design into three modules: the main box, the air box, and the
electrical system (which includes the DAQ devices) (Figure 3). All three systems fit on a single
table structure, with the air box on the lower section and the main box on the upper section, as
seen in figure 4. The air box and the main box are connected with ABS tubing and plastic
coupling.
Figure 3. Schematic of the final design
Figure 4. Detail 3D model of final design
Page | 4
1. Main Box
The main box, shown in figure 5, consists of all the physical components necessary to
test flow rate. The main box will be maintained at either a high or low pressure relative to the
atmosphere. When the pressure difference is negative, air will flow through the DUT and
DUT mount, through the metering element, and exit through the bottom of the main box.
Fluid elements in the form of baffles and flow straighteners are used to ensure that the
velocity upwind of the metering element is uniform and stable. When the pressure is high
relative to the atmosphere, the direction of air flow will be reversed.
Figure 5. Main box module
1.1. DUT Mount
The mount for the DUT (Figure 6) was designed specifically for the engine head
of the Honda CBR 600 F4i engine. The mount is manufactured from a solid block of
aluminum, with a height of 1 in, so that the bore adapter is not inset into the main box.
The mount has an aluminum engine bore adapter which is the same bore dimensions as
the cylinder of the CBR 600. Adapters with different internal dimensions can be used,
so any engine head with a maximum bore of up to 2.755 in (70mm) can be tested using
the same mount, provided that the adapter’s external dimensions remain the same. The
bolts that connect the mount to the main box screw into insert nuts, so the mount can be
removed without damage to the main box.
Page | 5
Figure 6. DUT mount and engine bore adapter
1.2. Metering Element
The metering element is a typical, sharp edged orifice plate (Figure 7). The plate
is machined aluminum with three orifices, each having a 41 degrees chamfer to a sharp
edge. The two unused orifices are blocked by a plug. Two plates were manufactured,
with orifices sized according to the analysis presented in Appendix E. The orifices are
positioned so there will be little interaction between the flow of the open orifice and the
neighboring plugs, and little interaction between the flow of the open orifice and the
nearby ledge. The plug consists of layers of plastic foam sandwiched between acrylic
plates. The plug is tightened by rotating the lower plate until an airtight seal is
achieved. The plate is secured to the main box using eight bolts, with wing nuts for
easy removal.
Figure 7. Orifice plate with foam plugs
Page | 6
1.3. Ductwork
The main box ductwork in figure 8 is constructed from 1/2 in Birch plywood
fastened together with 18GA crown staples, and sealed using wood glue and silicone.
The team selected hardwood plywood because it has relative high bending stiffness,
and allows for onsite manufacturing. The drawback of plywood is the tolerance in
manufacturing can only be  1/4 in, although this tolerance is acceptable for the
selected ductwork. The size of the material was proved to be strong enough to
withstand the loads under maximum operating condition (Appendix F). Rubber gasket
material or silicone sealant is used at all fastened locations to prevent leakage. Flow
straighteners, are inserted upwind of the metering element to ensure a smooth and even
flow profile entering the meter, and also serves to stabilize the pressure measurements.
Taps are located 2.5 in on either side of the orifice plate, and 3 in below the
main box inlet. The door on the front of the main box is made from clear acrylic, which
is stiffened by two angle-iron pieces to prevent deflection in positive pressure mode,
which would create leakage. The door is sealed by two toggle clamps, which provide
the clamping force necessary to prevent leakage during positive displacement mode.
Foam weather strip is used to seal the top of the main box, the metering element, and
the door.
Figure 8. Main box ductwork
Page | 7
2. Air Box
The air box is made up of three main modules: the pump, the flow control, and the
ductwork as in figure 9.
Figure 9. Air box assembly
2.1. Pump
The pump used is an Ametek Lamb 119892-00 tangential vacuum pump (Figure
10). The minimum capacity for the pump is at least 160 cfm at a pressure of 34 inH2O
as determined by the pump sizing analysis presented in Appendix G. This pump is rated
for up to 210 cfm at this test pressure, so the pump is oversized by a factor of 1.3.
Additionally, it is the most powerful pump option available to the team that stays under
the power restrictions of the VMS team lab, which are set at 16 A. The pump housing is
vented to prevent overheating. The pump is connected to the air box by aluminum
flanges, which are sealed using rubber gasket material.
Page | 8
Figure 10. Ametek Lamb 119892-00 vacuum pump.
(Images courtesy of Ametek, http://ametekfsm.com)
2.2. Flow control
The air box has two inlets and two outlets, so the box can be rotated to switch
the direction of flow (Figure 11). The pipes connecting the air box to the main box are
made from 4 in ABS tubing and connected together with flexible coupling, which
allows for easy removal of the main box. The other inlet is connected to a swing-gate
style bleed valve, which is controlled by a damper actuator (Figure 12). The actuator is
mounted on a custom aluminum bracket and attached to the valve with steel spacers. A
plastic sleeve connects the bleed valve shaft to the connecting shaft, which is rotated by
the actuator. When the valve is opened in negative pressure mode, a portion of the air to
the pump is atmospheric, rather than having come from the main box. While in positive
pressure mode, the opened valve allows some of the flow to exhaust to atmospheric
instead on into the main box. Either case will result in a lowered test pressure.
Figure 11. Direction of air flow through the air box
Page | 9
Figure 12. Bleed valve assembly
2.3. Ductwork
The ductwork of the air box (Figure 13) is designed to fit within the size
restrictions of the PDS, and is designed so that the exhaust will at no point face the
user. The air box was fabricated under the same method and material as the main box.
Figure 13. Air box ductwork
Page | 10
3. Electrical system
The three parts of the electrical subsystem are: the measurement system, the electrical
circuit and control system, and the user interface. The physical components reside within a
wood electrical box placed beside the main box as shown in figure 14.
Figure 14. Physical electrical component in the electrical box.
3.1. Measurement system
The DAQ system must measure the pressure differential between the
atmosphere and the test plenum, the pressure differential across the metering element,
and the temperature in the test plenum. The flow testing device utilizes both digital and
analog methods for measuring these values. Specifications for the digital manometers
used are outlined in Appendix H. The analog devices will ideally be used only as a
reference for the digital readings. However, they also ensure that the device is
functional without a computer. The analog pressure sensors are Magnehelic dial
pressure gauges, which are compact and easy to read. Pressure measurements are made
digitally from pressure transducers, which can measure positive and negative pressure
differentials. The pressure meters that measure the differential from atmospheric to the
Page | 11
test plenum have a range of +/- 30 inH2O and the differential meters across the orifice
have a range of +/- 10 inH2O. Temperature is measured digitally by a thermistor
attached as one leg in a voltage divider. Analog temperature measurements are made
with a standard household thermometer. The output is read by a National Instruments
(NI) USB 6008 DAQ device and converted into pressure and temperature values using
NI’s software, Labview. The circuitry for the sensors, as well as the sensors themselves,
are mounted atop through-style prototyping board, with wire wrap connecting the pins
on the underside of board. This allows for easy maintenance without the possibility of a
user accidentally interfering with the circuitry. The proto board and the NI USB 6008
are attached to the electrical box using acrylic mounts. The pressure meters are
connected to the main box ductwork by 1/4 in flexible tubing using galvanized steel
flanges with brass fitting barbs.
3.2. Electrical circuit and Controls system
The flow testing device requires two low and two high voltage sources: a 16V
DC source, a 24V AC source, and two 110V AC sources. The 16V DC source is used as
excitation voltage for the two pressure transducers and the thermistor. A 12V DC
voltage regulator is used to provide a steady voltage to the pressure sensors. Similarly,
a 5V DC voltage regulator is needed to reduce voltage across the thermistor voltage
divider.
The 24V DC is used to power the bleed valve actuator. Transformers for both
the 16V DC and 24V AC sources are connected to the same 110V AC plug via a
standard wall outlet located in the electrical box. The 16V DC and the 24V AC circuits
operate on individual, toggle style switches on the front of the electrical box. These
switches have embedded LED lights to indicate when the circuit is plugged in and
when it is switched on. A separate 110V AC supply is necessary to power the pump.
The supply is operated by a separate switch located on the front of the electrical box.
Figure 15 is the schematic of the electrical system.
Page | 12
Figure 15. Schematic of the electrical system
Figure 16. Test pressure controls schematic. The VI uses the difference between the measured pressure and the
desired pressure to increase or decrease the NI USB 2008’s output voltage.
Page | 13
The bleed valve attached to the air box is opened or closed automatically using
the Dweyer DDC damper actuator described in Appendix I. The actuator takes a 0 to 5
V modulating floating point voltage signal and converts it to an open position, where 0
V relates to a fully closed valve and 5 V relates to a fully open valve. The voltage signal
is provided by the NI USB 6008 and regulated by the Labview software as in the
control schematic in figure 16. The desired test pressure and tolerance is input by the
user via the user interface.
3.3. User Interface
The operator interacts with the DAQ and controls system through the Labview
User Interface shown in figure 17. The upper left box (1) contains the real time
numerical outputs of most interest to the user: the volume flow rate, the test pressure,
the meter pressure, and the temperature. To the right are dial gauges (2) that provide a
quick indicator to the user that the digital readings match the analog readings. To the
right of that are graphs (3) that indicate the raw voltage output of the sensors. The raw
voltage output is used to determine whether the system has reached a steady state. The
collect button (4) records a number of data points, specified by the user, to a text file.
The collect button records all values mentioned before as well as the mass flow rate, air
density, and atmospheric pressure. When the flow rate exceeds the specified range for a
particular orifice meter, a warning indicator activates above the voltage graphs.
1
4
2
3
Figure 17. User interface with: 1) real time data output, 2) visual pressure indicators, 3) steady state
indicators, and 4) controller pressure input.
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Final Product Evaluation
During Final Product Evaluation, the team showed that the device meets the requirements
set by the customer in the PDS document. The team used the specific verification methods listed
in that document, as well as additional methods which would provide additional evidence that
the device has met its targets. The PDS targets, the method used, and the result achieved for the
most important PDS requirements, previously listed in the “Product Design Specifications”
section, are presented as evidence that the device (Figure 18) performs as required by the
customer.
Figure 17. The prototype of the flow testing device, located in the VMS team lab
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1. Performance
The performance of the device was evaluated on its volume flow rate capacity, pressure
diffential capabilities, and automation by the performance of full scale tests on the final
prototype, which involved running the device though the entire range of its capabilities. The
following results were found.

The prototype was set up to run both ways—to both pull and push the air—and it was
able to perform from 0 to 145 cfm of flow at a test pressure of 5 to 40 inH20 with a max
capacity of 140 cfm at 22.5 inH2O. This is less than the target of 160 cfm at 28 inH2O,
perhaps because time constraints prohibited the device from having a comprehensive leak
test. By eliminating leaks and performing additional fine tuning, the device should move
air at a higher capacity. Further optimization of the air box would improve the capacity,
because sacrifices in the efficiency of the airbox were made in order to improve the
packaging and ease of maintinence.

The bleed valve is able to fully open and close to adjust the range of volume flow rates
from 0 to 145 cfm. The controller is able to adjust the test pressure specified by the user
in the Labview UI from 5 to 40 inH2O within a minimum user defined tolerance of 0.3
inH2O.

The pressure gauges and the pressure sensors give values within 1 inH2O of each other,
for both the 10 inH2O and for the 30 inH2O range meters. This was confirmed by running
the flow bench through a sweep that covered both the positive and negative ranges of all
pressure meters. The thermistor is able to measure the temperature of the main plenum,
and corelates within 2 °F of the thermometer. These values are easily read from both the
user interface of the Labview software and the guage dials.
2. Repeatability
The team performed an experiment as described in Appendix J, wherein a system curve was
created for a 1.414 in diameter orifice plate DUT. The pressure was controlled automatically
from 10 inH2O to 24 inH2O, with pressure and flow rate recordings taken by Labview.
Results show a repeatability of measurements is within 95%. Representative results are
shown in figure 19.
Page | 16
Differential Pressure, inH2O
4
3.5
3
Trial 1
Trial 2
2.5
Trial 3
2
1.5
80
90
100
110
120
Volume Flow Rate, cfm
130
140
Figure 18. Results for three trials measuring the flow rate using the largest orifice meter. Results are
repeatable to 95%.
3. Geometry and Size
The device fits on a steel table structure, which was measured to have a footprint of 3 ft by 2
ft. This is within the maximum footprint specified in the PDS of 4 ft by 6 ft. The height of the
device from the floor to the top of the main box is 46.5 in, which allows for people of
average height of 5 ft 10 in to easily manipulate a DUT attached to the mount. The final
device fits in the space provided by the VMS team.
4. Ease of Maintenance
The PDS requires that users be able to inspect and replace the parts of the device with ease.
This is achieved through three means:

Because of the modular design of the three subsystems (main box, air box, and
electrical), only one subsystem must be dissasembled to fix most problems.

The main box and air box are accessible by opening the top, which takes a single
person less than three minutes. All parts that could require maintinence are acessible
from the top when the lid is open.

Maintenance of the DAQ circuitry is simplified due to the use of wire wrap instead of
solder.
The verification method that these means are adequate to meet PDS requirements is based on
the capstone team and customers’ analyses of the design, as well as how well the team
adhered to the design.
Page | 17
5. Safety
The main safety concerns outlines in the PDS are the high volume of noise from the pump
and the risk of electrical shock. The first was evaluated by a simple test and the second by the
final design of the product, with the following results.

Noise levels were tested at head level for a person of average height, both standing in
front of the device and sitting at a computer next to the device. The highest noise level
recorded is 92 dB, which is just below the 95 dB required by VMS.

Electric shock is prevented by separating the high and low voltage wires and using a
regulation switch for controling the pump. In addition, the three power supplies all are
regulated with their own indepent switches. The user is not exposed to any open wires
during operation.
6. Cost
The total cost of all the parts and manufacturing of the device was $1,339, which is less than
the requirement of $1,500 set by the Maseeh College of Engineering and Computer Science.
The complete bill of materials can be found in Appendix K.
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Conclusion
The FSAE Flow Testing Device capstone team set out to develop a prototype device that
is capable of measuring the volume flow rate of air through components of the Viking
Motorsports’ engine components at a test pressure of 28 inH2O. Through the design process, the
team developed a final, top-level design that evolved into a final detailed design through the use
of various engineering analysis techniques.
The final working prototype of the device was manufactured by the capstone team
according to the detailed design and has been evaluated with respect to the PDS set at the
beginning of the process. Physical testing for performance of the device shows that the prototype
meets all design specifications, except for the maximum capacity requirement. Future
modifications to the air box and a comprehensive leak test will bring the maximum capacity up
to the required value. Other tests and evaluations confirm that the device meets all other PDS
requirements.
The prototype device has been approved by the Powertrain Design Group component of
Viking Motorsports, and resides in the VMS team lab, where it is currently available for engine
component testing. Future modifications and testing to increase the capacity of the prototype will
be performed by both the FSAE Flow Testing Device group members and by VMS team
members.
Page | 19
Appendix A: 2011 VMS Powertrain Components
This section describes the components that VMS requires to test for mass flow rate or flow
coefficient. The kind of information needed and the specific mounting requirements of each
component are detailed.
A1. Intake Manifold
This is a device that disperses the air that comes through the restrictor to the
individual cylinders. In order to determine if all four cylinders are receiving the same
amount of air, the mass flow rate through each runner must be calculated. A custom test
fixture needs to include a bracket with all four 25 mm openings, with three plugs. Flow only
needs to be measured at a negative pressure differential.
Figure A1. Intake manifold.
A2. Throttle/Restrictor
This piece contains the throttle butterfly valve; VMS needs flow coeficients for the
valve and mass flow at wide open throttle. The custom test fixture would need a 25 mm
adapter with properly placed holes for the bolts, as well as a mechanism for controlling the
degree of opening in the throttle valve. Flow only needs to be measured at a negative
pressure differential.
Page | i
Figure A2. Throttle body.
A3. Exhaust
After combustion, the air in the engine is expelled to the atmosphere through the
exhaust. VMS needs to know the pressure loss in this ductwork. The exaust will be mounted
in a similar fashion to the intake manafold. This part needs a positive pressure differential.
Figure A3. Exhaust system.
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A4. Cylinder Head
The cylinder head contains the valves that regulate the intake and exhaust flow
through each cylinder. Reliable flow confinements are needed for each valve for 1-D engine
simulation software. The head needs a custom 67 mm bore adapter and a device for
controlling the valve lift. The cylinder head needs to be measured under both negative and
positive pressure differentials.
Figure A4. Engine head (Honda CBR 600cc F4i).
Page | iii
Appendix B: Detailed Product Design Specifications
This section contains the product design specifications in their full and updated forms. Most
importantly, the capacity, size, and verification methods have been updated to better reflect the
customer’s priorities.
Table B1. Main requirements from the Product Design Specifications.
Priority
Requirement
Customer
Metric
Target
Target
Verification
Basis
Performance

Repeatability of
VMS
% error
(+/-) 5
measure flow

Capacity
Test intake, throttle,
Testing
feedback
VMS
cfm at
≥160 at 28
inH2O

Customer
VMS
Yes/No
Group
Testing
decision
Yes
muffler, valves
Customer
Design
feedback
Safety

Emergency stop
VMS
Yes/No
Yes
Customer
Testing
feedback

Warning labels
VMS
Yes/No
Yes
Customer
Design
feedback

Egonomics safety
VMS
Yes/No
Yes
Customer
Testing
feedback
Environment

Low noise
VMS
dBA
95
Customer
Design
feedback
Page | iv
Ergonomics

Number of operators
VMS
people
1
Customer
Testing
feedback

Training time
VMS
hours
5
Group
Testing
decision
Size and Weight

Footprint
VMS
feet
6x4
Customer
Design
feedback
Maintenance

Easy to inspect and
VMS
Yes/No
Yes
replace parts

Frequency of required
Customer
Design
feedback
VMS
months
6
maintenance
Customer
Design
feedback
Installation

Time to set up
VMS
min
20
Customer
Testing
feedback

Required specialized
VMS
Yes/No
No
power source
Customer
Design
feedback
Cost

Total cost
PSU
USD
1,500
Customer
Bill of
feedback
materials
Documentation

PDS
PSU
Deadline
01/30/2012 Course
Receipt
requirement
Page | v

Progress report
PSU
Deadline
03/05/2012 Course
Receipt
requirement

Final report
PSU
Deadline
06/11/2012 Course
Receipt
requirement

Instruction
VMS
Yes/No
Yes
Customer
Hard copy
feedback
Applicable codes and standards

Meets industry
VMS
Yes/No
Yes
standards
Customer
Study of
feedback
regulations
Customer
Bill of
feedback
material
Customer
Design
Material

Reasonable price
Team
Yes/No
Yes
Life in service

Continued operation
VMS
years
5
with approriate
feedback
maintenace
Manufacturing facility

Design parts for
manufacturability
Team
Yes/No
Yes
Group
Design
decision
Page | vi
Appendix C: Details on Alternative Designs
Design 1: The basic design (figure C1) meets the
PDS cost and functionality requirements as simply
and inexpensively as possible.

Single orifice plate meter

Analog pressure and temperature
measurement devices

PVC ductwork

Inexpensive shop vacuum and a manual
restriction valve

No flow alternator
Figure C1. Schematic of Design 1 executing intake testing.
Design 2: The balanced design (figure C2) meets the PDS cost and functionality requirements
with the addition of fast measurement turnover.

Multiple orifices plate meters

Large settling chambers before/after flow meter with laminar grid

Digital temperature and pressure measurement devices

High pressure centrifugal air pump (single or multiple in parallel/series)

Manually controlled flow diverter

Flow alternator (not shown in figure C2).
Figure C2. Schematic of Design 2 executing intake testing.
Page | vii
Design 3: The ideal design (Figure C3) meets the cost and functionality requirements with the
addition of fast measurement turnover and high accuracy.

Hot wire anemometer

Digital temperature and pressure measurement devices

High pressure centrifugal air pump (single or multiple in parallel/series)

Fully automated flow control

Flow alternator (not shown in figure C3)
Figure C3. Schematic of Design 3 executing intake testing.
Table C1. Advantages and disadvantages of the alternative design ideas
Design
Design 1
Advantages
Disadvantages
Inexpensive
Low repeatability
Simple set-up
Slow measurement turnover time
Easy to manufacture and maintain
Narrow operating range
Small footprint
Manual data analysis
High repeatability
Medium operating range
Design 2 Easy to maintain
Large system losses
Automatic data analysis
Design 3
High repeatability
Expensive
Large operating range
Longer set-up time between experiments
Fast measurement turnover
Hard to maintain
Automatic data analysis
Page | viii
Appendix D: Concept Selection Methodology
The goal of the concept evaluation is to determine the best possible design in an unbiased
and technical way. The team achieved this by using a weighted concept scoring matrix. The team
first took the key PDS requirements selected by VMS and assigned them importance scores from
1 to 3. These scores indicate the extent to which VMS desires the design to exceed the minimum
requirements.
The following list describes the importance scores of the requirements and the basis
factors that impact them.
Cost

Importance: 1.5
A cost lower than PDS requirements would be beneficial to VMS, but is not essential.
Therefore, cost is of medium low importance.

Basis: Initial cost of the flow element, DAQ, flow system, and also maintenance
costs.
Repeatability

Importance: 3
Because the flow testing device is a measurement device, repeatability is very
important.

Basis: Relative uncertainty of the metering element, resolution of the DAQ, and level
of control over the air flow.
Maintenance

Importance: 1
VMS would like the least amount of required maintenance possible. However, this is
not as important as the functionality of the device.

Basis: Replacement frequency and accessibility of key components.
Turnaround Time

Importance: 3
Turnaround time is of high importance, because a higher turnaround time would
allow for more experimental treatments, resulting in more accurate data.
Page | ix

Basis: Quickness of measurements during a single experiment, the time the device
takes to reach a steady state value, and how long it takes to reverse the flow. Does not
include time needed to set up the experiment.
Ease of Use

Importance: 1.5
It is important that the device is easy to use and take measurements, however it is
more important that the device can make repeatable and fast measurements.

Basis: Amount of training required, ease of taking measurements, digital or analog
readout, the need to adjust the device between experiments, and the need for manual
calculations are all taken into account in this section.
The team used the SuperFlow 450 and the PDS cost requirement as baselines to compare
the three designs. The team gave each design a value from 1 to 5. A value of 1 represents a
design with significantly worse functionality than the baseline, and a value of 5 represents a
design that meets or exceeds the baseline. Table D1 is the resultant concept scoring matrix.
Table D1. Concept scoring matrix for Designs 1, 2, and 3. Designs are scored from 1 (worst) to 5 (best)
compared to the baselines. Scores are multiplied by the requirement’s importance and summed to create their
total points.
Requirement
Importance
Design 1
Design 2
Design 3
1.5
5
3
1
Reliability
3
2
5
5
Maintenance
1
5
5
2
Turnaround Time
3
1
4
5
1.5
1
3
4
Weighted score
23*
41*
39.5*
Cost
Ease of Use
*50 pts possible
Page | x
Appendix E: Orifice Size Analysis
Summary
The goal of this analysis is to determine the size and number of orifice plate flow meters to
measure a volume flow rate from 20 to 200 cfm in the flow test bench with a design stage
accuracy of 95%. The result should be a table that can be used to identify what the min and max
volume flow rates for a plate are, given its size.
Result
Orifice
Dia
Max Q
Min Q
In
cfm
cfm
2.4
215.3
131.0
2.0
149.5
91.0
1.6
95.7
58.2
1.3
63.2
38.4
1.1
45.2
27.5
0.9
30.3
18.4
These values are reasonable when compared to orifice meter diameters of similar systems. The
overlap in flow ranges will allow for repeatable measurements throughout the capacity range of
the device.
Given
The (gauge) pressure inside the plenum directly below the DUT will be held at 28 inH2O with
respect to atmospheric pressure. Due to pump size restrictions and the resolution of the pressure
gauge, the differential pressure between the first and second plenum should be between 3 and 8
inH2O +/- 0.5 inH20. The total range measureable from the max flow rate of the largest orifice
to the min flow rate through the smallest orifice should be between 20 cfm and 250 cfm. There
must be at least a 5 % overlap between the Qmin of one orifice and the Qmax of the next smallest
orifice.
Find
The total number of orifice plates required and the diameter of each orifice plate.
Page | xi
Schematic
(1)
(2)
Assumptions
Orifice size calculations use the assumption of NTP (normal temperature and pressure) for
ambient conditions outside the test plenum. The values are
Temperature, T0 = 20 °C
Pressure, P0 = 101,325 pa
Density, ρ0 = 1.204 kg/m3
A discharge coefficient of 0.60 is assumed for all orifices. Real values will be determined
experimentally.
Solution
According to ISO5167, the volume flow of a gas through an orifice plate obstruction meter is
calculated from
2𝑍𝑅𝑇1 ∆𝑃
𝑄 = 𝐶𝐴0 𝑌√
𝑀𝑃1 (1 − 𝛽 4 )
where 𝑄 is the volume flow rate, 𝐴0 is the orifice bore area, 𝑇1 is the test temperature, ∆𝑃 is the
𝐷
differential pressure across the orifice meter (𝑃1 − 𝑃2 ), 𝛽 is the diameter ratio 𝐷 𝑜𝑟𝑖𝑓𝑖𝑐𝑒 and 𝑍, 𝑅,
𝑝𝑙𝑒𝑛𝑢𝑚
and 𝑀are fluid properties of air. The compressibility factor 𝑌 is
1
𝑃1 𝑘
𝑌 = 1 − (0.351 + 0.265𝛽 4 + 0.93𝛽 8 ) (1 − ( ) )
𝑃2
where k is the gas specific heat ratio.
Page | xii
𝐷𝑜𝑟𝑖𝑓𝑖𝑐𝑒 4
For the flow test bench with the largest orifice, 𝛽 4 = 𝐷
𝑝𝑙𝑒𝑛𝑢𝑚
=
2.5 𝑖𝑛4
12 𝑖𝑛
= .0016. Therefore the
term (1 − 𝛽 4 ) ≅ 1 and can safely be neglected. The max pressure ratio across the orifice will be
0.78, and so the max compressibility factor 𝑌 will be
1
𝑌 = 1 − (0.351 + 0 + 0) (1 − (0.78)1.4 )
= 1 − .023868 = 0.98
For design applications, this too can be neglected.
Result
Orifice Dia
Max Q
Min Q
in
cfm
cfm
2.4
215.3
131.0
2.0
149.5
91.0
1.6
95.7
58.2
1.3
63.2
38.4
1.1
45.2
27.5
0.9
30.3
18.4
References
[1] International Organization of Standards - ISO 5167-1:2003 Measurement of fluid flow by
means of pressure differential devices.
Page | xiii
Appendix F: Main Chamber Sizing Analysis
Summary
The object of this analysis is to test whether the thickness of the material used to construct the
main box is sufficient against to all of the loads during the operation of the flow bench. The
material was preliminary chosen as 0.5 in plywood, which is the thinnest standard size of good
quality wood panel. Going to the thicker one will lead to more expensive and heavier to be
picked up by one person. Therefore, the main chamber must be as inexpensive, light and strong
as possible. The expected result of this analysis is the location and magnitude of the maximum
displacement on the main chamber.
Results
Maximum displacement is 0.028 in, happens at the middle point of the top plate of the main box.
Formulation
Given: A 0.5” thick cabinet is made from plywood. The cabinet has two chambers, each
chamber will support the pressure as in figure F1. A 20lb engine head is placed on top of the
cabinet.
Wengine head = 20 lbf
P1 = 28 in H2O
P2 = 35 in H2O
Figure F1. Main box structure and the applied loads
Find: The location and magnitude of the maximum displacement
Page | xiv
Assumptions:
The modulus of elasticity of wood is 30MPa and the poison ratio is 0.33
All of the joins are perfectly rigid
Solution:
A finite element analysis was performed using ABAQUS. Since the structure is symmetry, only
half of the model was used in the analysis with appropriate boundary conditions.
Analysis type: static with linear geometry deformation
A fixed boundary condition (Ux = Uy = Uz = 0) was applied to the bottom of the chamber and a
symmetry boundary condition was applied to all of the edges on the symmetry plane as shown in
figure F2
Figure F2. Boundary conditions
Three loads were applied to the model. A pressure load equivalents to the load from a 20lb
engine head was apply to a portion on the top surface of the box. A negative 28inH2O pressure
load was applied to the upper chamber. A negative 35inH2O pressure load was applied to the
lower chamber (Figure F3)
Figure F3. Applied pressure for the structure
Page | xv
4-node shell element type was used. The Von Mises stress study converges to a model of 4443
elements.
Results:
Figure F4. Total displacement of the structure with a displace scale factor of 100 (the unit in the legend is
millimeter)
The maximum displacement is 0.028 in (0.7226 mm), which is very small compared to the size
of the main chamber (16 in x 19 in x 21.5 in). The location of the maximum displacement is at
the middle point of the top plate of the main box.
Page | xvi
Appendix G: Pump Size Analysis
Summary
This analysis aims to determine the pump pressure in feet (head) required to maintain a negative
or positive pressure (relative to atmospheric) of 28 inches water column at the test plenum with a
flow rate capacity of 160 cfm. This result will be used as the maximum operating condition when
selecting the blower. The result should be in the form of a pressure value in inH2O.
Result= 34.13 inH2O
The result is reasonable, and is low enough that the team will be able to select a pump with the
required capabilities and is in budget. These conditions represent the maximum capacity
requirements the pump will see. Losses in the system are approximate, so the final pump chosen
should be oversized by at least 1.3.
Evaluation
Given
The device shown below represents the ductwork of the flow testing device. Conditions at point
1 are test conditions, with a test pressure of 28inH2O. Point 2 is atmospheric.
Schematic
(1)
(2)
Page | xvii
Assumptions
Air properties are taken relative to normal temperature and pressure (NTP) which is 20 °C and
14.7 psia, respectively. (i.e., a differential pressure of 1 psi would mean an absolute pressure of
13.7 psia.) Air velocity inside the first and second plenum, and outside the flow bench, is
assumed to be 0, due to the relatively small diameter of the orifices and pipes. Density change
within the flow bench is assumed to be 0 (for example, no density change between plenum 1 and
plenum 2). There is no leakage in the system, so the same volume air will flow through all
components.
Given
Test pressure, 𝑃𝑇 = 28 𝑖𝑛𝐻2 0
Volume flow rate at max capacity, 𝑄 = 160𝑐𝑓𝑚
Pipe diameter, 𝐷 = 3.5 𝑖𝑛
Max orifice pressure drop, ∆𝑃𝑂𝑅𝐼𝐹𝐼𝐶𝐸 = 8 𝑖𝑛𝐻2 0
Required
Suction pressure required by the pump to maintain a test pressure of 28 inH2O and a volume
flow rate of 160 cfm.
Solution
The governing equation for this system is the standard fluid energy equation
[𝑃 +
̅
̅
𝜌𝑈
𝜌𝑈
+ 𝛾𝑧] = [𝑃 +
+ 𝛾𝑧] + 𝑃𝐿 − 𝑃𝑝
2
2
1
2
̅ is the mean velocity, 𝛾 is the dynamic viscosity, and 𝑧
where 𝑃 is the pressure, 𝜌is the density, 𝑈
is the elevation above a reference height at a particular point (1, 2) in the system. 𝑃𝐿 and 𝑃𝑝 are
the total system pressure losses and the required pump pressure. The pressure losses in the
system come from the drop across the orifice plate meter (∆𝑃𝑂𝑅𝐼𝐹𝐼𝐶𝐸 ), as well as the sudden
contraction, the 900 elbow, and the sudden expansion between (2) and (3). The pressure loss
across each of these elements is
𝑃𝐿 = 𝐾𝐿
̅2
𝜌𝑈
𝜌8𝑄 2
= 𝐾𝐿 2 4
2
𝜋 𝐷
where the individual 𝐾𝐿 values are taken from [1] as
𝐾𝐿,𝑆𝐶 = 0.45
Page | xviii
𝐾𝐿,𝑆𝐸 = 1 −
𝐴2
≈1
𝐴1
𝐾𝐿,𝐸𝐿𝐵𝑂𝑊 = 0.3
𝐾𝐿,𝐴𝑖𝑟𝑏𝑜𝑥 = 4.0 (𝑐𝑜𝑛𝑠𝑒𝑟𝑣𝑎𝑡𝑖𝑣𝑒 𝑎𝑠𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛
The pressure drop across the orifice is
∆𝑃𝑂𝑅𝐼𝐹𝐼𝐶𝐸 =
𝜌𝑄 2
(𝐶𝑑 𝐴𝑜 )2
The density inside the flow bench is assumed constant and is
248.72 𝑃𝑎
101,325 𝑃𝑎 − 28 𝑖𝑛𝐻2 0 ∙
𝑃
𝑘𝑔
1 𝑖𝑛𝐻2 0
𝜌=
=
= 1.12 3
𝐽
𝑅𝑇
𝑚
(287.04
) (293.15 𝐾)
𝑘𝑔 ∙ 𝐾
The max pressure drop across the orifice is 8 inH2O as per previous analysis. Taking 𝑈at both
points and the pressure at (4) to be 0, and taking the reference height to be 𝑧4 , required pump
pressure reduces to
𝑃𝑝 = 𝑃𝐿 − 𝑃𝑇 − 𝛾𝑧1 = 𝐾𝑄 2 − (𝑃𝑇 + 𝛾𝑧1 )
where
𝐾 = ∑ (𝐾𝐿
𝜌8
𝜌
𝜌8
𝜌
)+
= (𝐾1 + 𝐾2 + 𝐾3) 2 4 +
2
4
2
(𝐶𝑑 𝐴𝑜 )
(𝐶𝑑 𝐴𝑜 )2
𝜋 𝐷
𝜋 𝐷
= (0.45 + 1 + 0.3 + 4.0)
1.12
𝑘𝑔
∙8
𝑚3
𝑚 4
𝜋 2 (3.5 𝑖𝑛 ∙ 0.0254 𝑖𝑛)
𝑘𝑔
= 266,500 7
𝑚
1.12
+
𝑘𝑔
∙8
𝑚3
(0.6)2 ∙ 𝜋 2 (2.4 𝑖𝑛 ∙ 0.0254
𝑚 4
𝑖𝑛)
These equations allow for a quadratic system curve 𝑃𝑠𝑦𝑠 = 𝑃𝑝 = 𝑓(𝑄 2 ), which shows the
relationship between volume flow rate and pump pressure for any value of 𝑄.
𝑃𝑝 = 266,500 𝑄 2 − (−28 𝑖𝑛𝐻2 0 ∙
248.72 𝑃𝑎
+ ~0) = 266,500 𝑄 2 + 6964.16 𝑃𝑎
1 𝑖𝑛𝐻2 0
For the max flow rate conditions, the pump pressure is
Page | xix
2
𝑚3
1 𝑠
𝑃𝑝 = 208,046 (160 𝑐𝑓𝑚
) + 6964.16 𝑃𝑎 = 8464.24 𝑃𝑎
2118.8 𝑐𝑓𝑚
Result= 34.13 inH2O
References
[1] Okiishi, Wade W. Huebsch. Fundamentals of Fluid Mechanics, 6th Edition
Page | xx
Appendix H: Digital Manometer Specifications
Page | xxi
Appendix I: Actuator Specifications
Page | xxii
Appendix J: Experiments
Repeatability evaluation experiment
Background:
The flow bench created by the team hasn’t got any specifications available relating to the
reliability of the measurement. The reliability of the device is based on the variation in
measurement taken by the device on the same item and under the same conditions, or, in other
words, its repeatability. The device does not have a predetermined reliability and, because it is
one of the top priorities of the device, it was necessary to determine the repeatability of
measurements.
Apparatus:
The test for this experiment consisted of a calibrated orifice plate where the diameter of the
orifice hole is 2.4 inches. The calibrated orifice plate was bolted into the mount of the device so
that the holes were concentric. The gasket was wrapped around to avoid the leaking gas. The
flow bench was set up for the biggest orifice inside the device.
Theory:
As the diverter was slowly opened to create different pressures, the computer connected to the
flow bench determined the volume flow rate at a certain test pressure. The recorded data gave us
the curve depending of the volume flow rate to the test pressure. After the first set of data was
done, the orifice plate was disassembled and reassembled to avoid systematic error. The test was
performed again, and three different sets of data were recorded. The curves were compared to
determine the repeatability of the flow bench.
Data:
Figure J1 demonstrates three curves of the volume flow rates at different test pressures. These
experiments were considered to have the same testing conditions, as the air temperature, ambient
pressure, and tested item remained the same throughout.
Page | xxiii
Differential Pressure, inH2O
4
3.5
3
Trial 1
Trial 2
2.5
Trial 3
2
1.5
80
90
100
110
120
130
140
Volume Flow Rate, cfm
Figure J1. The volume flow rate at different test pressures for three trials.
Conclusion
The table shows that, under the same testing conditions (temperature, ambient pressure,
humidity, tested item), the results exactly matched with each other. The repeatability meets the
PDS requirements as it reaches 95%. This information validates that the device is reliable.
Page | xxiv
Appendix K: Bill of Materials
This section contains the bill of materials (BOM) including all expenditures for building the prototype flow testing device. The BOM
is organized by subsystem (DAQ, Main Box, Air Box, and Other) and includes the item function, the manufacturer (Mfg), the product
or pin number (P/N), the source the team acquired the part from, and the total cost of the part. The total subsystem cost is stated at the
bottom of each table.
Table K1. Bill of material
Page |
Table K1. Bill of material (cont.)
Page | i
Table K1. Bill of material (cont.)
Page | ii
Appendix L: Project Plan
Table L.1 shows the project plan followed by the team. Major projects are labeled in bold. A summary of symbols is found at the
bottom of the table.
Table L.1. Project Gantt chart.
Page |
Appendix M: User Manual
FSAE Flow Testing Device
User Manual
Contents
Safety ...........................................................................................................................................xxx
Warning: Risk of electric shock .............................................................................................xxx
Warning: Wear ear protection ................................................................................................xxx
Setting up an experiment ........................................................................................................... xxxi
Setting up the Main box ....................................................................................................... xxxi
Setting up the software......................................................................................................... xxxi
Running the experiment ............................................................................................................ xxxii
Running the Labview Program ........................................................................................... xxxii
Taking measurements ........................................................................................................ xxxiii
Controlling test pressure .................................................................................................... xxxiii
Page |
Safety
Warning: Risk of electric Shock.
Do not open the Electrical Box while the device is plugged in to a wall outlet. Ensure all
switches are set to off in between experiments. Do not operate if there is any visible wear to
wires
Warning: Wear ear protection.
Noise levels while the pump motor is running exceed 85 dB. Wear ear protection at all times
when the device is in use.
Page | i
Setting up an Experiment
Setting up the Main Box
Begin each experiment by firmly attaching the DUT to the top plate using the provided bolts and
sleeves. Select the orifice meter you will use, ensuring the other two orifices on the particular
plate are firmly blocked using the supplied plugs as shown in figure 1.
Figure M.1. Orifice plate meter
Use the supplied wing nuts and bolts to secure the orifice plate meter into the Main Box divider.
Ensure the chamfer is on the upwind side of the orifice plate. Close the door and secure with the
toggle clamp latches.
Setting up the Software
Open the Labview file named “FSAE_Flow_Testing_Device” and select the “Experiment Setup”
tab. Choose the file path you wish to save experimental data to using the Save Path control below
by either typing the desired path or clicking on the
icon and selecting the desired save path.
Page | ii
Next, fill in the field of Number of data points, which is the number of samples which will be
collected each time the “Collect” button is pressed, Misc, which can be anything from the trial
number to the number orifice plate you are using. Finally, adjust the atmospheric pressure if
necessary.
Next, select the orifice you are using by the number written on the orifice plate in the “Orifice #”
control. If you are not using one of the supplied orifices, then select “0” and enter custom data
for the orifice diameter, discharge coefficient, and max and min flow rates.
Finally, click on the “User Interface” tab in the top left corner.
Running the experiment
Running the Labview Program
Plug the two power cables into wall outlets. The black plug corresponds to the low voltage
devices and can be plugged into any wall outlet. The white plug if for the pump, and must be
plugged into an outlet that can supply up to 16 A. If possible, use different circuits for each plug.
The LED’s on the toggle switches on the front of the Electrical Box should be red. Flip the left
toggle switch up, so that the color changes to green. Open the Interface tab and press the “run
program” button on the Labview toolbar.
Page | iii
Check to make sure there are voltage readings from the DAQ and all indicators show 0 +/-0.2V
except the temperature, which should read room temperature.
Taking Measurements
Turn on the blower by flipping the bright red switch on the right side of the electrical box. Once
the graphs on the right side of the Interface shows steady state, press the collect button. Repeat if
necessary.
Controlling Test Pressure
If you would like to adjust the test pressure, first make sure the “Controller OFF” indicator is
red. Then turn on the right toggle switch on the Electrical Box. Type the test pressure you desire
into the “Desired Test Pressure,” control in the interface, and then enter the tolerance in the
“tolerance” control. Press the “Controller OFF” button so it changes to “Controller ON.” Note:
this can only decrease the test pressure, not increase it.
Page | iv
Appendix N: Part Drawings
Pump dimensions (from www.ametekfsm.com)
Page |
Engine Bore Adaptor
Page | i
Engine Mount
Page | ii
Orifice plate
Page | iii
Pump outlet flange
Page | iv
Pump spacer
Page | v
Actuator mount
Page | vi
Connecting shaft
Page | vii
Main box woodwork
Page | viii
Main box woodwork (cont.)
Page | ix
Main box woodwork (cont.)
Page | x
Main box woodwork (cont.)
Page | xi
Main box woodwork (cont.)
Page | xii
Air box woodwork
Page | xiii
Air box woodwork (cont.)
Page | xiv
Air box woodwork (cont.)
Page | xv