FSAE FLOW TESTING DEVICE
PRODUCT DESIGN SPECIFICATION REPORT
WINTER 2012
Group members
Adam Barka
Jasper Wong
Keith Lundquist
Long Dang
Vu Nguyen
Portland State University Advisor
Dr. Chien Wern
Industry Advisor
Evan Waymire
Table of Contents
Introduction ................................................................................................................................. 1
Purpose of this PDS Document................................................................................................... 2
Mission Statement....................................................................................................................... 2
Project Plan ................................................................................................................................. 3
Customer Identification .............................................................................................................. 4
Customer Feedback/Interviews ................................................................................................... 4
Product Design Specification ...................................................................................................... 5
House of Quality ......................................................................................................................... 8
Technical Risk Management....................................................................................................... 9
Conclusion ................................................................................................................................ 11
Appendix ................................................................................................................................... 12
Introduction
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. To overcome this, 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,
also known as the flow coefficient of the DUT, is calculated from the volume flow across the
meter and from temperature/pressure measurements at the DUT. Figure 1 shows a typical flow
bench operating under a negative pressure differential (relative to atmospheric). 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.
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 flow bench.
The other option is to buy a home build kit. These “do it yourself” (DIY) kits include key
components and/or detailed plans with which to build a flow bench. The kit is a more affordable
option. However, the measurements provided by flow benches built from DIY kits have
unspecified uncertainty. In addition, they generally require manual calculation to attain the flow
rate, which leads to low treatment turnover. Finally, DIY options would also need customized
test fixtures to mount all components.
Purpose of this PDS Document
The purpose of this document is to outline the customer’s requirements and the team’s
plan to meet those requirements. The Product Design Specification document must clearly define
the design criteria, metrics, targets, and priorities to meet customer requirement. Some core
criteria include cost, capacity, accuracy, and service life. A detailed list of criteria is provided in
the Product Design Specification section. The team and our customers will agree on this
document as a principal guideline for product delivery.
Mission Statement
This team is challenged to design and build a device capable of measuring the flow
coefficients for the intake, exhaust, 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, bill of material, and detailed reports, will be presented in June
2012. If successful, the project would help the VMS team to validate and improve their designs.
2
Project Plan
The dates in Table 1 are critical milestones for the project. A Gantt chart is provided in
Appendix B and will be considered as a living document. Dates other than due dates are
subjected to change, dependent on the project requirements.
Table 1. Project Milestones. The team will work on the Tasks between the Start and
Finish dates. Due dates reflect times when the tasks must be delivered to the customers.
Task
Start
Finish
Due
Project Planning
Jan 9
Jan 13
N/A
PDS Report
Jan 9
Jan 29
Jan 30
PDS Report Presentation
Jan 31
Feb 3
Feb 6
External and Internal Search
Jan 19
Feb 5
N/A
Concept Evaluation
Feb 6
Feb 13
N/A
Detail Design
Feb 13
Mar 5
N/A
Progress Report
Feb 7
Mar 11
Mar 12
Progress Report Presentation
Mar 1
Mar 4
Mar 5
Prototype and Test
Mar 24
May 23
N/A
Final Report
Apr 24
May 25
N/A
Release Design to Customer
May 28
3
Customer Identification
For this project, two categories of customer exist: external customers and internal
customers. The first of the external customers is Viking Motorsports, who is the end user of the
testing device, and therefore provides the key performance, ergonomics, and size criteria.
Besides VMS, industry adviser Evan Waymire and faculty member Dr. Gerald Recktenwald are
also the team’s external customers, as they provide the cost and various performance parameters.
VMS’s use of the testing device will be scored by a team of judges at the FSAE competition,
therefore the competition judges are another customer for this project.
In addition there are three internal customers who must be taken into account. The first
two of these are Dr. Faryar Etesami and the Maseeh College of Engineering and Computer
Science, who provide the documentation requirements. Likewise, Portland State University is a
key customer, because the project must adhere to the school’s requirements for graduation.
Customer Feedback/Interviews
Direct feedback from the VMS powertrain team and Evan Waymire has been an integral
part of determining the design specifications for this project. The concept for the project was first
developed by Robert Melchione, who leads the VMS powertrain team. Rob proposed the idea
during the summer of 2011, as a way to make flow testing for the car an integral part of the
design and validation process. Until now, VMS has not performed flow testing on its engine
components. During the summer of 2011, preliminary meetings with Evan provided a basic
outline for what the design parameters would be. During that time, the mechanical engineering
department head, Dr. Recktenwald, held a meeting, during which he provided funding
information and advice for performing analysis and finding resources for this project.
The competition judges are also key customers, but we cannot interview them in person.
Given this, we have reviewed the FSAE rules (Appendix C) and feedback from the 2011 design
competition in order to extrapolate the design judge’s requirements for this project.
4
Product Design Specifications (PDS)
Table 2 is a representation of each customer’s design requirements, as well as applicable
parameters. These include the priority level of each, which are rated by the customer as either
high, medium, or low with three, two, or one dot, respectively, as well as the associated metrics
and targets and how that target will be verified. Some targets may change, with the customer’s
approval, based on detailed analysis of the system.
Table 2. Design Specifications
Priority
Requirement
Customer
Metric
Target
Target
Verification
Basis
Performance

Repeatability of
VMS
measurements

Flow Rate/Pressure
Test intake, throttle,
(+/-) 5
difference
VMS
Capacity

%
VMS
Waiting time to get
Testing
feedback
cfm,
≥160,
Group
inH2O
28
decision
Yes/No
Yes
Customer
muffler, valves

Customer
Prototyping
Design
feedback
VMS
Min
15
steady value
Customer
Testing
feedback
Safety

Emergency stop
VMS
Yes/No
Yes
Customer
Design
feedback

Warning labels
VMS
Yes/No
Yes
Customer
Design
feedback

Ergonomics safety
VMS
Yes/No
Yes
Customer
Design
feedback
Environment

Low noise
VMS
dBA
95
Customer
feedback
5
Design
Ergonomics

Easily acessible
VMS
Yes/No
Yes
Customer
Design
feedback

Number of operators
VMS
people
1
Customer
Testing
feedback

Training time
VMS
hours
5
Group
Testing
decision
Size

Footprint
VMS
ft x ft
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 assemble and
VMS
hours
4
disassemble

Time to set up
Customer
Testing
feedback
VMS
min
20
Customer
Testing
feedback

Required specialized
VMS
Yes/No
No
power source
Customer
Design
feedback
Cost

Total cost
PSU
USD
6
3500
Customer
Bill of
feedback
materials
Documentation

PDS
PSU
Deadline
01/30/2012 Course
Receipt
requirement

Progress report
PSU
Deadline
03/05/2012 Course
Receipt
requirement

Final report
PSU
Deadline
05/28/2012 Course
Receipt
requirement

Instruction
VMS
Yes/No
Yes
Customer
Hard copy
feedback
Applicable codes and standards

Meet industry
VMS
Yes/No
Yes
standards
Customer
Study of
feedback
regulations
Customer
Bill of
feedback
material
Customer
Final
feedback
product
Customer
Design
Material

Reasonable price
Team
Yes/No
Yes
Quantity

Number of devices
VMS
unit
1
Life in service

Continued operation
VMS
years
5
with approriate
feedback
mainternace
Manufacturing facility

Design parts for
Team
Yes/No
manufacturability
Yes
Group
decision
7
Design
House of Quality
The House of Quality (Table 3) relates the influence of the project requirements to
engineering criteria. Each cell within table has a '' symbol marker to relate the influence of the
project requirement to engineering criteria. The symbol ranges from '' high influence, to ''
little influence, if the cell is left blank then no influence. Also the importance of the requirements
is listed from a scale of one to ten, with the total score adding to ten.
REQUIREMENT
ENGINEERING CRITERIA
CUSTOMER
IMPORTANCE
Table 3. House of Quality
Weight
Flow
rate
Noise
level
USD
lb
cfm
dBA
Flow
Performance
SuperFlow


















VMS













3
Accurately Measure Flow
1
Capacity
1
Test Intake, Throttle, Muffler,
and Valves
1
SAFETY
2
Emergency Stop
2
ENVIRONMENT &
ERGONOMICS
1
Low Noise
0.5
OSHA

Training Required
0.5
VMS

MAINTENANCE
1
Easy to Inspect and Replace
Parts
1
VMS



COST
3
ME




Basic 2.0 (Flow Performance)
1600
100
600
101
SF-600 (SuperFlow)
9000
400
600
> 85
TARGET
3500
200
160
95
Verification
BOM
Inspect
Test
Test
Commercial Options
3
Basic 2.0
Cost
PERFORMANCE
Less Expensive than
COMPETITION
VMS

COMPETITION
8
SF-600
Technical Risk Management
To ensure the success of this project, we have identified the probable risks and their
associated consequences (Table 4). Depending on the probability of the risk event occurring and
its severity, we developed an in-depth mitigation and monitoring plan for high level risks,
summarized in Table 5.
Table 4. Risk Identification and Assessment
RISK
ASSESSMENT
ODDS OF
Project Exceeds
CONSEQUENCES
MITIGATION MONITORING
LEVEL
EVENT
OF
OCCURRING
RISK
Possible
Severe
High
Necessary
Necessary
Not Serviceable
Unlikely
Severe
Medium
Necessary
Necessary
Design too
Possible
Severe
High
Necessary
Necessary
Unlikely
Negligible
Low
Necessary
Unnecessary
Possible
Severe
High
Necessary
Necessary
Possible
Severe
High
Necessary
Unnecessary
Possible
Severe
High
Unnecessary
Unnecessary
Possible
Catastrophic
High
Necessary
Necessary
Budget
Complicated to
Fabricate
Team
Alignment and
Communication
Not Meeting
Deadline
Change in
Budget
Machine Does
Not Meet
Requirements
Injury to
Operator
9
Table 5. Risk Mitigation and Monitoring
Risk:
Injury to Operator
Design for acoustics will be limited to maximum
Mitigation:
Degree of Risk:
95dBA, and equipment operator will wear ear
plugs during equipment use. Kill switch will be
included for immediate shut off of equipment.
HIGH
Monitoring:
Acoustic levels will be tracked with dBA meter
on equipment periodically (monthly/quarterly).
Communication between team members and
Risk:
Not Meeting Deadline
Mitigation:
accountability for individual members to
complete tasks.
Degree of Risk:
HIGH
Risk:
Design is Difficult to
Manufacture
Degree of Risk:
HIGH
Weekly meetings with academic advisor, weekly
Monitoring: work parties, online communication, and Gantt
chart for project tracking.
Mitigation:
Monitoring:
Design for performance and manufacturability
Track all design changes on personal team server
and have design review meetings.
Use reasonable priced components during design
Risk:
Project Exceeds Budget
Mitigation:
of flow bench system. Validate component
choice with uncertainty analysis.
Degree of Risk:
HIGH
Create a B.O.M with different options for
Monitoring: different price levels that determine which to
build upon budget received
10
Conclusion
This document addresses the key specifications and issues of designing and
manufacturing a flow test bench for the Viking Motorsports Formula SAE team. Key areas of
difficulty or interest stem from designing to a wide and unique operating range in terms of
pressure, flow rates, part mounting, and data acquisition.
Developing a custom flow bench will greatly improve the quality of the VMS program by
allowing for the team to validate their designs to a far greater degree than in the past. In addition,
making the device available to the students at all times will provide future students the ability to
gain significant experience in part testing and increase understanding of how to incorporate part
testing into the design process. The availability of the device, when combined with detailed
documentation, will also give future VMS members the opportunity to improve on the device’s
functionality, thus creating long-term potential for improving the car. In the end, this team
believes that the device will give VMS a strong competitive advantage in competition, since very
few of the other FSAE teams have access to flow testing at this accuracy level.
11
Appendix A: 2011 VMS powertrain components
This section includes the components which VMS needs 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 the device which disperses the air which comes through the restrictor to the
individual cylinders. The mass flow rate through each runner is needed to determine if all 4
cylinders are receiving the same amount of air. A custom test fixture needs to include a
bracket with all four 25 mm, with three plugs. Flow only needs to me measured at a negative
pressure differentail.
Figure A1. Intake manifold
12
A2. Throttle/Restrictor
This piece contains both the throttle butterfly valve and so VMS needs flow
coeficients for the valve, and mass flow at wide open throttle. The custom test fixture would
need a 25 mm adapotor with properly placed holes for the bolts, as well as a mechanism for
controling the degree of opeing in the throttle valve. Flow only needs to me measured at a
negative pressure differentail.
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
13
A4. Cylinder Head
The cylinder head contains the valves which 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 adaptor and a device for
controlling the valve lift. The cylinder head needs to be measured under both negative and
positive pressure differential.
Figure A4. Engine head (Honda CBR 600cc F4i)
14
APPENDIX B
Table B1. Detailed Gantt chart
Detailed Gantt chart
15
APPENDIX C
2012 Formula SAE Rules
[…]
ARTICLE 8: POWERTRAIN
B8.1 Engine Limitation
B8.1.1 The engine(s) used to power the car must be a piston engine(s) using a four-stroke
primary heat cycle with a displacement not exceeding 610 cc per cycle. Hybrid
powertrains, such as those using electric motors running off stored energy, are prohibited.
Note: All waste/rejected heat from the primary heat cycle may be used. The method of
conversion is not limited to the four-stroke cycle.
B8.1.2 The engine can be modified within the restrictions of the rules.
B8.1.3 If more than one engine is used, the total displacement cannot exceed 610 cc and the air
for all
[…]
B8.5 Throttle and Throttle Actuation
B8.5.1 Carburetor/Throttle Body
The car must be equipped with a carburetor or throttle body. The carburetor or throttle
body may be of any size or design.
B8.5.2 Throttle Actuation
The throttle must be actuated mechanically, i.e. via a cable or a rod system. The use of
electronic throttle control (ETC) or “drive-by-wire” is prohibited.
B8.5.3 The throttle cable or rod must have smooth operation, and must not have the possibility
of binding or sticking.
B8.5.4 The throttle actuation system must use at least two (2) return springs located at the
throttle body, so that the failure of any component of the throttle system will not prevent
the throttle returning to the closed position.
Note: Throttle Position Sensors (TPS) are NOT acceptable as return springs.
B8.5.5 Throttle cables must be at least 50.8 mm (2 inches) from any exhaust system component
and out of the exhaust stream.
16
B8.5.6 A positive pedal stop must be incorporated on the throttle pedal to prevent over stressing
the throttle cable or actuation system.
B8.6 Intake System Restrictor
B8.6.1 In order to limit the power capability from the engine, a single circular restrictor must be
placed in the intake system between the throttle and the engine and all engine airflow
must pass through the restrictor.
B8.6.2 Any device that has the ability to throttle the engine downstream of the restrictor is
prohibited.
B8.6.3 The maximum restrictor diameters are:
- Gasoline fueled cars - 20.0 mm (0.7874 inch)
- E-85 fueled cars – 19.0 mm (0.7480 inch)
B8.6.4 The restrictor must be located to facilitate measurement during the inspection process.
B8.6.5 The circular restricting cross section may NOT be movable or flexible in any way, e.g.
the restrictor may not be part of the movable portion of a barrel throttle body.
B8.6.6 If more than one engine is used, the intake air for all engines must pass through the one
restrictor.
[…]
17