COMET: Spring Final Review April 21, 2014

COMET:
Spring Final Review
April 21, 2014
Team members:
Julia Contreras-Garcia
Eric James
Matthew McClain
Benjamin Woeste
Emily Ehrle
Jonathan Lumpkin
Megan O’Sullivan
Kevin Wong
Customer: Lt. Joseph Ausserer, USAF
University of Colorado Boulder
2
Outline
Test Stand
• Project Overview
▫ Objectives
▫ Requirements
▫ System block diagram
•
•
•
•
•
Engine
Harness
Shaft
Coupler
Design Description
Test Overview
Test Results
Systems Engineering
Project Management
Project Overview
Design
Motor &
Controller
Power Regulator
Power Dissipater
Models
Testing
Systems and
Management
Project Purpose and Objectives
Project Overview
Design
Testing
Systems and
Management
4
Project Description
• Design and build a Power Extraction Unit (PEU) for a
JetCat P90-RXi mini-turbojet engine (shown below) that
will generate 500 Watts of electrical power at 24 VDC.
• Sponsored by Air Force Research Laboratory’s
Aerospace Propulsion Outreach Program (APOP)
Harness
Engine
Generator
JetCat P90-RXi in
stock configuration
Solid Works model
Project Overview
Design
Testing
Systems and
Management
5
Applications
• Power extraction devices could be used on variety of military and
civilian Unmanned Aerial Vehicles (UAVs)
• Additional power would replace batteries used to power avionics
and/or sensors
• Power extraction unit to weigh
less than equivalent battery,
extending maximum flight time
or flight distance
Project Overview
Design
Testing
Systems and
Management
6
Objectives
• Level one
▫ PEU must generate power at 24 Volts DC
▫ PEU must produce this power after the engine has been running no
longer than 1 min 20 s, twice the average start up time
▫ Engine and PEU must be compatible with the WPAFB test stand
• Level two
▫ Reducing thrust by no more than 25%
▫ Increasing specific fuel consumption by no more than 50%
• Level three
▫ Adding no more than the weight than an equivalent battery pack with 30
minutes of power (8 lbs)
▫ Producing 500 W throughout the engine’s RPM operating range
• Level four
▫ PEU to be entirely external to the JetCat engine, making the most
modular solution.
• Red are not met, Green are predicted to be met
Project Overview
Design
Testing
Systems and
Management
Design Description
Project Overview
Design
Testing
Systems and
Management
8
Design Description
• Design solution overview
▫ 3-phase brushless motor to act as power generator
▫ Motor has to act as starter until engine can run by itself (~35,000 RPM)
• Critical subsystems
▫ Mechanical
 Commercial coupler to connect
engine and motor shafts
 Alignment harness to align shafts
▫ Electrical
 Control switching of motor
between startup mode and power
generation mode
 Power conditioning circuitry to
convert AC signal to DC
▫ Software
 Data acquisition
 Modeling
Project Overview
Design
Testing
Systems and
Management
9
Detailed System Block Diagram
Direct Current
24 V
2.0 Amps
Power
Power
Dissipation
Regulation
Three phase
9.33-16.00Vpp
6.27-5.02 Amps
35,000-42,000 RPM
Information used to Verify Models
Shaft 0.0487 Nm – 0.0390
coupler
Engine Power Model
P90rxi Engine
Motor
B40-8LDD
Rotor Dynamics
Test Stand
Motor Controller
(Phoenix 80)
Project Overview
2 kHz 10V
PWM motor driving signal
50 Hz
Servo PWM
Throttle Signal
Design
Manufactured
by COMET
Motor Controller Circuitry
Testing
Systems and
Management
10
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Critical Project Elements
• Generating electrical power
▫ Req. 1.0 – The design solution shall generate 500 Watts of electrical power
• Attaching motor to engine shaft to provide torque transfer
▫ Req 3.1 – The rotational energy of the main engine shaft shall supply the energy needed
via a generator.
• Aligning motor shaft and engine shaft to mitigate vibrations
▫ Req. 3.4 - The design solution shall maintain the engine balance.
• Switching circuitry to force motor to start engine up and then switch to generate
electricity
• Convert three phase AC power output from motor into DC power
▫ Req. 2.4 - Power generated shall be transmitted using 24 V DC.
Project Overview
Design
Testing
Systems and
Management
Test Overview
Project Overview
Design
Testing
Systems and
Management
12
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Testing Overview: Major Tests
Test Name
Category
Location of Execution
Completed
Engine Characterization Test
Mechanical
Software
Boulder Airport
✔
Low RPM Test
Mechanical
Electrical
Aerospace Instrument Shop
✔
Circuitry Switching Test
Electrical
Aerospace Instrument Shop
✔
Final System Test
Mechanical
Electrical
Software
Boulder Bomb Squad Facility
• Completion defined as accomplishing test purpose, (e.g. verifying requirements, verifying
models, verifying functionality etc.)
Project Overview
Design
Testing
Systems and
Management
13
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Engine Characterization Test
• Test Purpose:
▫ Verify MATLAB Simulink engine
model for stock engine
configuration
▫ Provided baseline engine
performance information
• Location: Boulder Airport
• Requirements Verified:
Req #
Requirement Text
1.2.1
A method of measurement of fuel flow shall exist.
4.1.1
The test stand shall support clamps that are fitted to the engine.
4.1.2
The test stand shall have an axial load cell for means of measuring thrust.
Project Overview
Design
Testing
Systems and
Management
Models
14
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Low RPM Test
• Test Purpose:
▫ Verify shaft connection for
RPM’s between 0-15,000
▫ Verify motor controller
circuitry ability to drive
motor
• Location: Aerospace
Instrument Shop
• Requirements Verified:
▫ No direct requirements
verification, functional test
only
Project Overview
Design
Testing
Systems and
Management
Models
15
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Motor Controller to Power Regulator Circuitry Switching
• Test Purpose:
▫ Verify system can properly
switch between motor driving
and power generating modes
• Location: Aerospace
Instrument Shop
• Requirements Verified:
Req
#
2.2.3
Requirement Text
Power regulator shall be able to accept
voltage input from generator.
Project Overview
Design
Testing
Systems and
Management
16
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Final System Test
Power
Dissipater
Models
• Test Purpose:
▫ validate entire system can perform to expected standards
• Location: Boulder Bomb Squad Facility
• Requirements Verified:
Req #
Requirement Text
1.1
The design solution shall not decrease stock thrust by more than 25%.
1.1.1
The design solution shall not output torque high enough such that it will stall the engine.
1.2
The design solution shall not increase the thrust specific fuel consumption by more than 50%.
1.3.1
The design solution must operate above 35,000 RPM, the bottom edge of the engine idle range.
2
Power generated shall be transmitted using 24 V DC current.
3
The design solution shall be able to derive power from a JetCat P90-RXI engine.
3.1
The rotational energy of the engine shaft shall be converted into electrical energy via a generator.
3.4
The design solution shall maintain the engine balance.
4
The design solution, when integrated with the JetCat P90-RXI engine, shall interface with the
test stand designed by the customer and the test stand available through CU.
4.1
The dimensions of the design solution integrated with the engine shall not exceed those shown
below in Figure 2.4-1.
Project Overview
Design
Testing
Systems and
Management
17
Harness
Test Stand
Motor &
Controller
Shaft
Engine
Coupler
Power
Regulator
Power
Dissipater
Models
Final System Test
Current
Power Dissipater
Measurements
Instrument
Output Voltage
Direct DAQ input
Output Current
Pololu +/- 31 A current sensor
Fuel Flow Rate
Equiflow PVDF 0045 flow meter
Engine Thrust
Test Stand Button Load Cell
RPM
Generator output signal
Voltage
Motor
Controlling
Circuitry
Voltage
Rectifier
Relays
RPM 35,000 to ~56,000
~30 ft
Engine
Boulder Bomb Squad
Dugout
Generator
USB Webcam
Flow
Meter
Project Overview
Schedule
Load Cell
ECU
NI 9234
DAQ USB cable
Fuel Tank
NI 9205
Earth Berm
NI 9401
LabVIEW
DAQ Chassis
Repeater
Subsystems
Budget
Test Results
Project Overview
Design
Testing
Systems and
Management
19
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Engine Characterization
• Acquired average thrust and average fuel flow rate vs. RPM for the P90-RXi
engine
• Baseline data for later performance effect analysis
Project Overview
Design
Testing
Systems and
Management
20
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Coupling System
Req #
Requirement Text
Verified by:
3.1.2
Connection shall be secure from 0 to 60,000 RPM
Coupler torque test
3.3.1
Electric motor and engine shafts shall be held in alignment so the shafts are not
offset by >0.15 mm (0.0059 inches) and 1.5°
Coupling system
integration/inspection
Project Overview
Design
Testing
Systems and
Management
21
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Coupling System
Req #
3.1.2
Requirement Text
Verified by:
Connection shall be secure from 0 to 60,000 RPM
Coupler torque test
• Commercial-off-the-shelf coupler rated to operate at 42,000 RPM, above
idle speed (35,000)
▫ Shafts began slipping in coupler at 0.7 Nm




Max engine torque of 0.193 Nm
Factor of safety (FOS) of 3.63
Uncertainty in measurement, ~0.01 Nm
Uncertainty does not affect meeting the requirement
• Coupler limits engine operational range
▫ Coupling method from original design would operate over larger part of
operational range
▫ To fulfill all original design requirements, new coupler or coupling method
would be required
Project Overview
Design
Testing
Systems and
Management
22
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Coupling System
Req #
3.3.1
Requirement Text
Verified by:
Electric motor and engine shafts shall be held in alignment so the shafts are not
offset by >0.15 mm (0.0059 inches) and 1.5°
Coupling system
integration/inspection
• Alignment Harness
▫ Precision milled for predicted offset of 0.0005” from milling
accuracy
 Reduced during assembly due to human inaccuracies
▫ Max measured offset between shafts of 0.0034”, for FOS of 1.74
 Uncertainty of 0.001” from caliper accuracy
 Even with max error, still within requirement range with FOS of 1.34
▫ Angular offset was 0.16°, for factor of safety of 9.4
 Uncertainty of 0.23°, from 0.01” measuring inaccuracy
 Even with max error, have FOS of 3.85
Project Overview
Design
Testing
Systems and
Management
23
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Motor to be used as Starter/Generator
Req #
Requirement Text
Verified by:
1.0
PEU shall generate electrical power.
Full-system test
1.3
PEU must operate above 35,000 RPM, the lower edge of the engine idle range.
Full-system test
• New motor controller selected after original was shorted
▫ Selected based upon availability and functionality (from Aerospace Electronics shop)
Parameter
Required
Phoenix 80
Current
15A
80A
Speed (2 pole)
35,000
210,000
Voltage
16V
24V
Project Overview
Design
Testing
Systems and
Management
24
Test Stand
Engine
Harness
Motor &
Shaft
Controller
Coupler
Power
Regulator
Power
Dissipater
New Motor Controller System Circuitry
PWM
generator
Averaging Circuit
comparator
Summing amplifier
Power
Relays
Timing
chip
Project Overview
Design
Testing
Systems and
Management
Models
25
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
End of motor control circuit comparison
Frequency:
Amplitude:
Duty Cycle:
Model: 49.8 Hz
Model: 5V
Model: 5.8 %
Project Overview
Design
Measured: 48.9 Hz
Measured: 4.94 V
Measured: 6.0 %
Testing
Error: 1.84%
Error: 1.2%
Error: 3.45%
Systems and
Management
Models
26
Harness
Test Stand
Shaft
Coupler
Engine
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Power Regulation
Req #
Requirement Text
Verified by:
2
Power generated shall be transmitted at 24 VDC
Full-system test
2.2.1
Power regulator shall keep the max ripple below 2.4V
Power reg. funct. test
2.2.3
Power regulator shall accept voltage input from generator
Motor Controlling-Power
Regulating switching test
2.2.4
Power regulator shall accept input frequencies of 1750 - 6250 Hz
Full-system test
8.05-14.72 V
Peaks
Bridge Rectifier
Project Overview
▫
Generator Voltage
drives power
limitation
• Voltage ripple of
0.5 Vpp
To Ground
3-phase
9.33-16V
• 50 Watt DC-DC
regulator outputs
24 Volts
8.05-14.72 V
~0.4 Volt Ripple
Smoothing Capacitor
Design
24 Volts
0.5 Volt Ripple
DC-DC Regulator
Testing
Systems and
Management
27
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Power Regulation: Rectifier
• Test in two parts due to limitations of function generator
• 6 Vpp input from 3 synchronized signal generators
Project Overview
Design
Testing
Systems and
Management
Models
28
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Power Regulation: Rectifier
Voltage at input to DC-DC regulator
Voltage between input and ground
• Slightly higher voltage drop
than expected
▫ Expect regulator turn on at
39,000 instead of 37,800 RPM
Project Overview
Design
Voltage drop
Testing
Expected
Measured
1.28 V
1.6 V
Systems and
Management
29
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Power Regulation: Regulator
• Test in two parts due to limitations of function generator
• Used DC power supply to provide voltage input
• Output loaded with power dissipater
Project Overview
Design
Testing
Systems and
Management
Models
30
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power Regulation: Regulator
Power
Dissipater
Models
Required
Expected
Measured
Error
Voltage
24-28 V
24.0 V
23.8 V
0.8%
Ripple
2.4 V
0.24 V
0.24 V
0.2%
48 W
47.95
0.1%
Power
(Goal)
500 W
• Voltage output fails original
objective of 24-28V output
▫ Output will be corrected before
demonstration to Air Force in
Late May
DC-DC regulator output
• Power output fails original objective of 500Watts
▫ Due to lack of COTS regulators capable of boosting 9V to 24V at 500W
▫ Insufficient time to design custom regulator
Project Overview
Design
Testing
Systems and
Management
31
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Low RPM Test
• Verified the motor controller circuitry controls the ESC
• Verified the ESC can smoothly commutate to motor from 0-15,000 RPM
• Verified coupler was able to transmit torque between engine and motor
Measured BLDC motor driving
signal from Oscilloscope
Project Overview
Design
BLDC motor droving signal from
motor control theory application note
Testing
Systems and
Management
32
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Motor Controller to Power Regulator Switching Test Results
• Verified circuitry could switch between the motor controller side and
the power regulator side
• Picture shows oscilloscope probing on the power regulator side
Expected result
seen, signal went
from 0V to 5.4V
Shows Relays Switched
Input to Power Regulator
Motor Controller being used to drive motor
Project Overview
Design
Testing
Systems and
Management
33
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Power Dissipation
Req #
Requirement Text
Verified by:
2.3
A board shall be created to verify the power output of the power regulation system.
Power dissipation
functionality test
• A 2 ohm and 10 ohm resistors dissipate the 48 Watts generated
▫ Measure voltage drop across resistor to verify 24 Volt output of DC-DC regulator
▫ Current sensor used in conjunction to verify power output matches predictions
• A buffer op amp has been added since
TRR to make the voltage divider’s
impedance compatible with DAQ
measurements
Project Overview
Design
Testing
Systems and
Management
34
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Power Dissipation: Results
• Dissipater used to verify power
output of system
▫ Uncertainty is 1.2% of expected
system power
Project Overview
Design
Max
Uncertainty
Voltage
0.04 V
Current
0.03 A
Power
0.58 W
Testing
Systems and
Management
Models
35
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Engine Model Predictions
Engine Model (no-load) predictions: Verified
Engine Model (load) predictions: To be Tested
• Predictions from model indicate requirements will
be met.
• Predictions will be verified during Full System Test
Req #
Design
Verified
by:
1.1
Not decrease stock thrust by >25%
Full-system
test
1.2
Not increase stock thrust specific
fuel consumption by >50%
Full-system
test
Derive electrical power from a
JetCat P90-RXI engine at 24 V DC.
Full-system
test
3
Project Overview
Requirement Text
Testing
Systems and
Management
36
Harness
Test Stand
Engine
Shaft
Coupler
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Final System Test: Status
• Currently having problems starting the engine with the
integrated design solution
▫ Error: Engine fails due to a temperature bound error
• Cause has been narrowed down to 3 possibilities:
1. Extra fuel forced into system is increasing temperature
2. Engine’s exhaust gas temperature thermocouple is malfunctioning
3. Reduced mass flow due to inlet impedance is causing overheating
• Next Steps:
▫ Iterative testing with decreasing fuel input to see when temperature drops
enough for engine to run
▫ Iterative testing of changing EGT thermocouple position in exit flow
▫ Reduce RPM engine needs to reach to run
Project Overview
Design
Testing
Systems and
Management
37
Harness
Test Stand
Shaft
Engine
Coupler
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Overall Project Results
• Did not achieve customer’s original goal of 500W power generation
over the operational range of the engine
▫ Had to take off-ramp design solution due to supply chain problems
▫ Original design was modeled and predicted to achieve customer’s goals
▫ 48 Watts predicted
Parameter
Expected
Required
Output
Voltage
24 V
24-28V
Thrust
Reduction
8-10%
<25%
TSFC
increase
<5%
<50%
• When these predictions are verified by final system test, the results
can be scaled up to original design goals
Project Overview
Design
Testing
Systems and
Management
38
Harness
Test Stand
Engine
Shaft
Coupler
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Overall Project Results
• Original design would have been able to satisfy all
functional requirements
▫ Original starter motor/generator would have produced 18V at ~60,000
RPM
▫ Original Power Generating range was 60,000-112,000 RPM, ~55% of
engine operational range
▫ Original DC-DC regulator in Power Regulator Subsystem required 18V to
begin generating 500W of power.
▫ Custom coupler could be ordered that would operate up to 100,000 RPM,
increasing the operational range
Project Overview
Design
Testing
Systems and
Management
System Engineering
Project Overview
Design
Testing
Systems and
Management
40
Systems Engineering Summary
• Define project objectives
▫
▫
Customer-defined requirements
Produce 500W at 24VDC
• Define system requirements
▫
▫
System-level requirements
Minimize impacts on stock system mass,
thrust, specific fuel consumption
• Concept generation and selection
▫
Trade studies and analyses
• Preliminary engineering design
▫
Off-ramps: Lower RPM starter generator,
lower rated coupler, passive signal
conditioning
• Component and subsystem testing
▫
▫
Electrical subsystem: Power regulation and
signal conditioning
Mechanical subsystem: Generator
alignment harness, coupling system
Work Breakdown Structure
• Integration testing
• Full-system testing
Project Overview
Design
Testing
Systems and
Management
41
Lessons Learned
• Plan for supply chain failures
▫ JetCat not providing original motor
▫ Set hard dates for taking off-ramps
▫ Set margins for other unexpected delays
• Outcome of project has strong dependency on
understanding of the schedule
▫ Major milestone: Receive JetCat motor
▫ Electrical: Could not measure signals without
motor
▫ Mechanical: Could not begin manufacturing of
alignment harness
Project Overview
Design
Testing
Systems and
Management
42
Systems Engineering Issues
• Interface and communication with suppliers of
critical project elements
▫ Poor/lack of communication from JetCat
▫ No updates about the status of motor
▫ Never received motor from Germany
• Many design changes throughout spring
semester
▫ Catch-up from lack of design in the fall
▫ Constant changes to subsystem/integration tests
▫ Devise and plan for contingency off-ramp plans
Project Overview
Design
Testing
Systems and
Management
Project Management
Project Overview
Design
Testing
Systems and
Management
44
Project Management Summary
• Goal: to help the design process operate as
smoothly as possible
▫ Understanding of project as a whole
▫ Allocate help where it is needed most
▫ Be aware of schedule and if project is on track or
not
• Key project management lessons learned
▫ Allow more time margins
▫ Do not rely on suppliers/JetCat
▫ Budgets can cause significant delays in project
 Obtaining parts sooner would have given more time
margins at the end of the project
Project Overview
Design
Testing
Systems and
Management
45
Budget
• Large variation in budget
due to team taking off ramp
• Significant over runs of cost
in testing area offset by
drops in cost of generator
and alignment harness
$3,000.00
$2,500.00
$2,000.00
Expected Vs. Actual
Expenditures
Predicted Cost
Actual Cost
$1,500.00
$1,000.00
$500.00
$0.00
Major Differences in Cost
Total Over budget
Engine
$1,051.15
$321.00
Other
Broken ECU
$591.50
Broken GoJett GSU
$184.99
Testing
Flow Meter inserts
$60.66
Custom ECU Cable
$168.49
Lab Battery Charger
$209.99
New Test Stand Battery
$86.99
Project Overview
Design
Hours
Direct Cost
Total Cost
Fall
1,327
$41,475
$124,425
Spring
(As of 4/18/14)
1,916
$59,866
$179,597
Total
3,243
$101,341
$304,022
Total project funds spent: $6155.86
Testing
Systems and
Management
Questions?
Project Overview
Design
Testing
Systems and
Management
Backup Slides
Project Overview
Design
Testing
Systems and
Management
48
Harness
Test Stand
Engine
Shaft
Coupler
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Overall Project Results
• Requirements not verified:
▫
Requirements specific to original 500W generation system
Req
#
1
1.3
2.2.2
Requirement Text
Reason for Non-verification
The design solution shall generate 500 W of
electrical power.
Off-ramp design solution not designed to produce
500W
The design solution shall generate the required
power while the engine is operating between
35,000 and 125,000 RPM
The “required power” refers to 500W, which the offramp design solution would not be able to produce
Power regulator shall be able to supply 21 Amps.
21 amps is from the 500W design solution
3.2
The generator shall be designed such that the
torque from the JetCat P90-RXI engine is sufficient
input to generate 500 W at the lowest operational
rotation rate, 35,000
3.5
The design solution shall begin to generate 500 W
after the engine has been running for one minute
and 20 seconds, twice the start up time of the
engine.
Project Overview
Design
Off-ramp design solution not designed to produce
500W
Off-ramp design solution not designed to produce
500W
Testing
Systems and
Management
49
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Test Stand
Req
#
Requirement Text
Verified by
A method of measurement of fuel flow shall
exist.
Inspection
The design solution, shall interface with the test
stand designed by the customer
Final
Demonstration
at WPAFB
4.1.1
The test stand shall support clamps that are
fitted to the engine.
Inspection
4.1.2
The test stand shall have an axial load cell for
means of measuring thrust up to 25 lbs.
Inspection
1.2.1
4
Engine Test Fire Set Up
50
unscrew
Pull off
unscrew
unscrew
51
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Coupling System: Additional Tests
• Coupler torque test
▫
▫
▫
▫
▫
▫
▫
Test if threaded engine shaft has enough surface area to make a
secure connection to coupler
Insert engine shaft into coupler and apply known torque using
lever arm and known weight
Find torque at which shaft slips in coupling
If torque reaches 1 Nm (10x greater than expected torque of 0.1
Nm), test will stop without testing to failure
Extra coupling purchased in case coupler is marred during test
If slip occurs before 1 Nm, shaft will be inserted into other side
of coupler and adhesive will be used to fill thread gaps
Torque will be applied and measured again after adhesive sets
Power
Dissipater
Engine shaft
simulator
Shaft
Coupler
Lever arm
Known weight,
added incrementally
Stock starter
• Stiffness test
▫
▫
▫
▫
Verify designed harness system is stiffer than stock system
displacement
Hang weight from stock starter
Measure displacement
Calculate displacement expected from designed system using
and substituting the force from the physical test
Known weight
Project Overview
Schedule
Subsystems
Models
Budget
52
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Low RPM Test: Additional Details
Purpose: To ensure shaft connections are stable to ~6,000 RPM
Facility: Senior Projects Room or Buseman Advanced concepts lab
Measurements
Instrument
Sampling Rate &
expected output
Purpose of Measurement
Shaft RPM
Engine Ground
Support Unit
~1 Hz
0-6,000 RPM
DATA NOT BEING RECORDED
Meant as a display of current RPM, not a
data recording device. If resonant frequency
found the RPM will be recorded by hand.
Frequency
Response
PCB +/- 2300 g
accelerometer
~25kHz
0-2 g’s
Monitoring vibrations during the test will
help reveal any shaft misalignments past the
tolerances of the shaft coupler.
Measurements will either verify that no
natural modes are excited and shafts are
aligned or show high amplitude vibrations
due to shaft misalignment
53
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Motor Controlling to Power Regulator Switching Test: Additional Details
Purpose: To ensure the relays can successfully and properly switch between the
motor controlling circuitry and the power regulating circuitry
Facility: Buseman Advanced concepts lab
Measurements
Instrument
Sampling Rate &
expected output
Purpose of Measurement
Voltage into Power
Regulator
Multimeter
N/a
0-1.6 V
DATA NOT BEING RECORDED
Measurement is to prove that the relays are
switching to the power regulator circuitry.
Voltage from 6,000RPM is not high enough
to pass the DC-DC regulator
See Low RPM Test additional details slide for other measurements
Project Overview
Schedule
Subsystems
Budget
54
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Power Regulator Functionality Test: Additional Details
The Signal: 3-phase sinusoidal wave,
120o phase shift between each sine wave
during the test voltage will vary between
9.33-16V to simulate generator signal at
35,000-60,000 RPM
-V
Facility: Tim May’s Electronics Lab
+V
Purpose: To verify the power regulator
is working properly
0o
120o 240o
The Function Generators: Three function generators will be used to simulate
this signal. All 3 will be synced using the built in syncing channel, then function
generator 2 will have a 120o phase shift and function generator 3 will have a
240o phase shift
Project Overview
Schedule
Subsystems
Budget
55
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Power Dissipater functionality Test: Additional Details
Purpose: to verify the power dissipation system can dissipate at least 50W of
power. Functionality includes the current and voltage sensors as well as the
labview VI to read and record current, voltage, and power.
Facility: Trudy’s Electronics Lab
Measurements
Instrument
Sampling Rate & expected
output
Output Voltage
Direct DAQ input
5 Hz
5-24 V
Output Current
Pololu +/- 31 A current
sensor
5 Hz
0-5 V (corresponding to 0-2 A)
Project Overview
Schedule
Subsystems
Budget
56
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Selection of New Starter/Generator
𝑉
𝑁𝑚 0.06313
𝑁𝑚
=
=
= 0.0023
𝑟𝑎𝑑/𝑠
𝐴
28
𝐴
𝑉𝑒𝑚𝑓 = ω𝐾𝑒𝑚𝑓 = 628.32 0.0023 = 1.42𝑉
𝑉𝑜𝑝𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔
6
𝑅1 =
=
= .214Ω
𝐴𝑠𝑡𝑎𝑙𝑙
28.08
𝑉𝑑𝑟𝑜𝑝 𝑎𝑐𝑟𝑜𝑠𝑠 𝑅1 = 3.24𝑡𝑒𝑠𝑡 − 𝑉𝑒𝑚𝑓 = 1.82𝑉
Motor Torque/Speed
Curve
(0,63.13)
Current Starter
Torque (mNm)
28.08A
𝐾𝑒𝑚𝑓 =
𝑉 = 𝐼𝑅 → 𝐼 =
0.85A
(2932.15,0)
Angular Velocity (rad/sec)
I
+
𝑉𝑎𝑝𝑝𝑙𝑖𝑒𝑑
𝑉 1.82
=
= 8.52𝐴
𝑅 .214
τ𝑚 = 𝐾𝑇 𝐼 = 0.0023 8.52 = 0.02𝑁𝑚
τ𝑚
0.02
=
= 8𝐴 + 2.3𝐴 = 10.3𝐴
𝐾𝑇 0.0025
𝑚𝑜𝑡𝑜𝑟 𝑜𝑝𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑐𝑢𝑟𝑟𝑒𝑛𝑡
45
=
= 4.37
𝑉𝑒𝑚𝑓 𝐹𝑂𝑆 =
𝑚𝑜𝑡𝑜𝑟 𝑐𝑢𝑟𝑟𝑒𝑛𝑡
10.3
𝐼=
Project Overview
Schedule
Subsystems
Budget
57
Test Stand
Engine
Harness
Motor &
Shaft
Controller
Coupler
Power
Regulator
Power
Dissipater
Motor Controller System Circuitry at TRR
PWM
generator
Averaging Circuit
comparator
Summing amplifier
Power
Relays
Timing
chip
Project Overview
Design
Testing
Systems and
Management
Models
58
Test Stand
Engine
Harness
Shaft
Motor &
Controller
Coupler
Power
Regulator
Power
Dissipater
Models
Engine: Main Tests
Stock Engine Characterization:
Completed
Measured engine fuel flow rate, thrust, and
frequency response over operational range
Data used to validate MATLAB Engine Model and
Rotor Dynamics Calculations, also provided
baseline performance
Engine
Quantity
Results
Max Speed
131,000 RPM
Max Speed During
Startup
53,000 RPM
Thrust at Max Speed
19.8 lbs
Max Fuel Flow
~330 mL/min
Max Temperature
725°C
ACC
NI 9234
NI 9205
Fuel Tank
NI 9401
Test Stand
Load
Cell
LabView VI
DAQ Chassis
Project Overview
Schedule
Subsystems
Budget
59
Harness
Test Stand
Engine
Shaft
Coupler
Motor &
Controller
Power
Regulator
Power
Dissipater
Models
Full System Test
Req #
Requirement
1.1
The design solution shall not decrease stock thrust by more than 25%
1.2
The design solution shall not increase the thrust specific fuel consumption by more than 50%
1.3.1
The design solution must operate above 35,000 RPM, the bottom edge of the engine idle range.
2
Power generated shall be transmitted using 24 V DC current
3
The design solution shall be able to derive power from a JetCat P90-RXI engine.
3.1
The rotational energy of the engine shaft shall be converted into electrical energy via a generator.
4
The design solution, when integrated with the JetCat P90-RXI engine, shall interface with the test stand
designed by the customer and the test stand available through CU.
4.1
The dimensions of the design solution and engine shall not exceed those shown below in Figure 2.4-1.
Facility: Boulder Bomb Squad
Test Duration: 2.5 hours (1 hour travel & set-up, 30 min testing, 1 hour pack up & travel )
Equipment: Test Stand Assembly, Fuel Flow Sensor, Load Cell, Accelerometer,
Design solution
Project Overview
Schedule
Subsystems
Budget
60
Travel
Travel Roster
Itinerary
Day
May 20
May 21
May 22
Activity
Travel to Dayton, OH.
Demonstrate project
Participate in group poster session and return
to Boulder, CO.
Item
Airfare
Hotel rooms
Per diem
Rental Car
Cost
$350 round trip
$120 per night
$56 per day
$125 per day for van
Name
Dr. Ryan Starkey
Matt McClain
Megan O’Sullivan
Ben Woeste
Jon Lumpkin
Kevin Wong
Eric James (Tenative)
Quantity
7 people
2 nights, 3 people per room*
8 people, 3 days
3 days
Total
Available
Role
Team Advisor
Project Manager
Test Engineer
Safety Officer
Electrical Lead
System Engineer
Software Lead
Subtotal
$ 2,450.00
$ 840.00
$ 1,176.00
$ 375.00
$4,841.00
$4,359.00
* Considerations have been made to give separate rooms to the men and women of the team; additionally the team’s
advisor has been given his own single room
• Currently $500 shortfall on travel for available team members
▫ Have funds to take 5 team members and Dr. Starkey
Project Overview
Schedule
Subsystems
Budget
61
Load Cell for Full System Tests
• Measurement
Specialties FX1901
Compression Load Cell
• Measurement Range:
0-10 lbf
• Excitation Voltage: 5
VDC
• Accuracy: 15% of span