investigation of air mover for small volume spot cooling applications
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Investigation of Air Mover for Small Volume Spot Cooling Applications. Design Group Members: Thomas Staley Andrey Tsinovkin Tuan Le Dan Somlea Faculty Advisor: James E. Morris Industry Advisor: Christopher Coleman. Background. - PowerPoint PPT PresentationTRANSCRIPT
Investigation of Air Mover for Small Volume Spot Cooling
ApplicationsDesign Group Members:
Thomas StaleyAndrey Tsinovkin
Tuan LeDan Somlea
Faculty Advisor:James E. Morris
Industry Advisor:Christopher Coleman
Background• A chip on the Differential Probes
produced by Tektronix overheats and is damaged in the process.
• Investigate and develop a practical component and a realizable method to move air in a small volume for the purposes of spot cooling.
Background
Design Requirements
Design Constraints• Limited Space• Must survive high acceleration
events• Easily manufactured• Low cost performance ratio
Possible Solutions• Axial Flow fan• Radial flow fan• Gear Pumps• Piston Pumps• Diaphragm Pumps• Corona Discharge
Design Selection• Rotating equipment is undesirable
– The target application may experience acceleration loads in excess of 20g difficult to stabilize rotating equipment under these conditions
– 10,000 hour lifetime creates incentive to eliminate wear parts.
– Rotating equipment is difficult to scale down to the desired level.
Designing for Reliability• Eliminate wear parts• Use solid state solutions wherever
possible• Durable structure and packaging!
Designing for Manufacturability
• Engineering materials based on manufacturing processes rather than design requirements when possible.
• Eliminate 3D part features by means of a 2D layering strategy. – Think of a soccer ball, it is a three
dimensional structure, but it is manufactured as a composition of 2D pieces.
Final Selection• A diaphragm pump concept was
chosen– A piezoelectric bending element was
used as the diaphragm– Solid state diffusers used as intake and
discharge valves– Manufactured from stainless steel in
three steps, assembled with silicone RVT
Piezoelectric Bender• Actuated electrically• Behaves like a diaphragm• Commonly used as speakers in portable
devices such as cellular phones, laptops, etc.
Piezoelectric Bender Modes of Vibration
Piezoelectric Advantages• Simple • Cheap• Reliable
Courtesy of CUI Inc. 2007
www.cui.com
Valves• The valves were constructed using
inline diffusers• Diffusers in this application operate
based on the principle of vena contracta
• The geometric arrangement acts as a high loss valve with no moving parts!
Diffuser Concept
Valve Assembly• A diaphragm pump
needs two valves to operate, a suction and discharge.
• Therefore the valve arrangement requires two inline diffusers
Valve Assembly
Putting It All TogetherExploded View
Putting It All TogetherPump Cross Section
Prototype Parts
Assembled Product
ResultsHot Film Anemometer
- JLC Industries EE57-1 Miniature Air Velocity Transmitter
- Peak velocity occurs at:First Prototype - 500-600 HzSecond Prototype – 5,000 – 6,000 Hz
- Peak velocityFirst Prototype - 120 lfmSecond Prototype -600 lfm at 5V @ 20mA
Heat Transfer Analysis- First Prototype
• 8.6% Difference in heat transfer coefficient- Second Prototype
• 42.8% Difference in heat transfer coefficient- Resistor – 0.25 watt Carbon Film Resistor
• 30% Reduction in thermal resistance
Results
Pump On/Off
47
48
49
50
51
52
53
54
55
40 45 50 55 60 65 70 75 80
Time (s)
Tem
p (
deg
C)
Pump On/Off
62
64
66
68
70
72
74
76
20 30 40 50 60 70 80
Time (s)T
emp
(d
eg C
)
Pump Off
Pump On
Pump On
Pump Off
Particle Image Velocimetry (PIV)
• Utilizes a sheet of light in a dark room to visualize particles moving in one plane
• The concept relies on CCD cameras to track the particles as a function of distance traveled over time
• Results provide speed and direction of the flow field
PIV Setup
Physical Setup
Flow VisualizationParticle Trace Image
More Flow Visualization
More Flow Visualization
Visualized Operation