1. Team P15441 Mini Air Sub-System Design Review
04/02/15

2. Team Introduction Team Member Major Role Daniel Probst
Electrical Engineer
Project Leader
Usama Haq
Mechanical Engineer
Lead Relations
Nathan Serfass
Technical Lead
Joshua Erbland
Electrical Design Lead
Alexander Cornell
Mechanical Design Lead
P15441
04/02/15

3. Agenda Background Customer and Engineering Requirements
Sub-System Overview & Specs Distribution
Sub-System Analysis and Specifications
Thermal
Air Flow
Housing
Electrical UI
Preliminary Mockup
Test Plan
Risk Assessment
Project Schedule
Budget
Summary
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4. Market State Features Cost Mini Air Cryothermic Scarf Handy Cooler
Forced Air
Thermoelectric
Rechargeable Battery
Cooling only
Cryothermic Scarf
Contact Thermoelectrics
Heating and cooling
4 hour battery life
Rechargeable battery
Handy Cooler
Forced Air
Water thermal storage
Cooling only
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Cost

5. Project Deliverables
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6. Customer Requirements
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7. Engineering Requirements
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8. Constraints Budget of $1000 UL Certifiable
Humidity factor for Temperature < 30%
Lot sizes of 10,000
Maximum Unit Labor Time of 5 min.
Airflow comfortable 4” from device 160° arc at neck
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9. System Architecture
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10. Subsystem Specs Distribution
Thermal
Air Flow
Electrical
Weight
55%
35%
10%
Cost
45%
Power
65%
30% 5%
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11. Thermal Analysis Current Process
Using a Matlab code to generate all potential values
Working with multiple SME’s to debug and validate solutions
Heatsink fin design
We believe a significant pressure drop exists at the heat sinks. Further analysis into the effect of the number of fins, surface area, and width between the fins will be conducted in the next phase.
Thermal Model
Currently verifying with SME’s and trying to validate solution with mock-up designs.
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12. Thermal Sub-System Overview
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13. Air Flow Analysis FIn/Motor Design
Identify Fan Pressures Fan Total Pressure
Fan Velocity Pressure
Fan Static Pressure
Design
Size
Trailing Edge of Blade
Hub Radius
nozzle design
cfms needed at exit
how does this relate to fan cfms
etc
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14. Housing CAD Drawings Analysis of why design was chosen
weights, sizes, etc
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15. Electrical Sub-System Overview
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16. Battery Considerations
Rechargeable
Battery Type
Voltage [V]
Energy Density [WHr/Kg]
Lead-Acid
2.1
30-40
NiCd
1.2
40-60
NiMH
1.3
80-100
Li-Ion
3.7
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17. User Interface Considerations
On/Off Power Switch Options - SPDT
Pushbutton
Rocker Switch
Slide Switch
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18. Power Regulation
A single Li-on or Li-po battery cell will be used assuming that a boost converter can be designed cheaply enough to achieve the voltage output we need for the thermoelectric module.
Advantages to 1 cell:
Simpler/cheaper battery charging system.
1 larger battery is cheaper than 2 smaller batteries.
Wider range of integrated solutions available.
Advantages to 2 cells:
Simpler boost converter design.
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19. Preliminary Mockup Parts: 7 cfm, 40 mm fan w/ brushless motor
Melcor 5629 TEM
40x40 mm heatsinks
Anemometer Readings:
Fan: 2.5 m/s (5.6 mph)
At Cold Side: 0.24 m/s
Thermocouple Readings:
Ambient: 71°F
Cold Side: 74°F
Hot Side: 127°F
Housing
Fan + Motor
Heatsinks
Hot Side
Thermoelectric
Cold Side
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20. Preliminary Mockup Rev. 2
Housing
Parts:
7 cfm, 40 mm fan w/ brushless motor
Melcor 5629 TEM
40x40 mm heatsinks
10x40 mm nozzle for cold side
Anneometer Readings:
Fan: 2.5 m/s (5.6 mph)
At Cold Side: 0.45 m/s
¼” Deflection of paper
Thermocouple Readings:
Ambient: 75°F
Cold Side: 64°F
Hot Side: 108°F
Hot Side
Thermoelectric & Heatsinks
Nozzle
Fan + Motor
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Cold Side

21. Preliminary Test Plan
Metric
Testing Method
Weight
Measure sub elements with scale
Velocity of air at fan
Velocity of air at exit port
Measure using anemometer
Temperature differential at heatsink
Temperature differential at exit port
Measure using thermocouple at heatsink
Unkown method for exit port
Battery Life
Measure power supplied to motor using multimeter
Measure power supplied to TEM
Measure power dissipation
Comfort
Perform survey of individuals with a prototype consisting of similar final weight
pass/fail criteria will be based upon engineering requirements
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22. Risks Assessment
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23. Schedule for Phase 4
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24. Budget Total Budget: $1000 Current Costs:
First Round Prototyping: $21.63
Second Round Prototyping: $6.97+
Future Potential Costs:
3D printed housing
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25. Summary
Technical Status: Power requirement is high and more R&D needs to be developed to better meet the customer requirements
Upcoming steps: Refining the thermodynamic model, get a better understanding of feasibility analysis, create subsystems and verify all results
Cost- Current budget is tight and suppliers need to be contacted for specific quotes
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26. Questions and Feedback
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27. References http://www.amazon.com/dp/B007OWTTAO?psc=1 – Cool-on-the-Go
- Cyrothermic Scarf
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