W IND –2– H 2 O MECH 4020: Design II Group 12: Jeffrey Allen Daniel Barker Andrew Hildebrand Tom McDonald Supervised by: Dr. Alex Kalamkarov Client: Dr. Graham Gagnon 1

Presentation Agenda 2 Background Design Overview Design Modifications Testing Budget Design Requirements

Design Competition Project inspired by theme of 2008 Design Competition posed by WERC: A Consortium for Environmental Education and Technology Development Competition held at New Mexico State University April 5 th – 8 th 3 Competition Design Challenge Design a device that uses wind power to directly power the filtration of brackish water i.e. no generation of electricit y

Interdisciplinary Collaboration Working with a team of two Civil Engineering students: Matt Follett Dannica Switzer Responsible for water treatment system 4

5 December 2008 Design

6 January 2009 Update

7 Completed Windmill

Design Overview 8

Design Overview - Blades 9 Clockwise rotation Blade tip deflection Light weight (Al 5052-H32) Safety factor of at least 10 for centrifugal forces Optimize performance for low winds (3-6 m/s) Solidity ratio of 80% 10 degree averaged angle of attack

Design Overview – Blade Attachment 10

Design Overview - Hub 11

Design Overview - Gearbox 12

Design Overview - Gearbox 13 1” diameter shafts 1010 steel for rotor shaft, 4140 steel for geared shafts Maintain a safety factor of at least 5 (keyways, variable loads) Stress analysis - torsion, bending, buckling, Vibration – critical speed Deflection – spacing between bearings

Design Overview - Gearbox 14 System meets or exceeds ANSI B Precision Power Transmission Roller Chains, Attachments, and Sprockets SizePitch, in.Roller diameter, in.Ultimate strength, lb.Working load, lb "0.312”3, "0.469"7,0301,980

Design Overview – Crank Mechanism 15 3 inch stroke length Brass bushings used to allow for relative motion between shaft and crank arm Cotter pins prevent crank arms from slipping off ends

Design Overview – Pump Block 16 Crank arm drives pump block up and down No relative motion between vertical shafts and pump block due to split pin (better for seal) Two ½” shafts constrain lateral motion through two brass sleeve bearings

Design Overview – Yaw Bearing 17 Lazy susan bearing rated for 1000 lbs. used to yaw the nacelle

Design Overview – Pump 18 Brass pipe with two check valves Leather seals provide seal between valves and pump wall

Design Overview – Stand 19 Stand inherited from Vertical Axis Wind Turbine 2005/2006

Design Overview – Overspeed Protection 20 Furling at 11 m/s Thrust force on blades Force on Tail Offset angles

Design Modifications 21

Design Iteration – Flange Thrust Bearing 22 THRUST BEARING Added to stop pump rod from unthreading itself during yaw motion Transmits tension and compression along pump rod, while providing zero torque Consists of a rigid flanged housing welded to the upper pump rod with two sets of tapered roller bearings press fit into it Lower pump rod locates onto roller bearings via a welded collar and tensioning nut

Design Iteration – Brass Pressure Seal Cap 23 Design Considerations SEAL CAP Added to provide a pressure seal at interface of pump rod and pump Consists of a brass cap with pipe threading that has seated in it a rubber wiper to prevent dirt from entering the pump, and a rubber seal

Design Iteration – Stainless Steal Pump Rod 24 Design Considerations STAINLESS STEEL PUMP ROD Originally made of steel, which was rusting Replaced with a stainless steel pump rod to resist corrosion

Testing/Results 25

Testing Test #1: Point Pleasant Park – Unstable back pressure (butterfly valve) – Wind speed ~4 m/s – Proof of concept test – No data recorded

Testing Test #2: Dalhousie Wind Tunnel Lab – Air flow: 42” box fan – Wind speed ~4.5 m/s – Filters couldn’t handle high flow rate – Unstable back pressure (butterfly valve) – Civil students were able to reduce particulate in sample from >6000 ppm to <150ppm 97.5% particulate removed!

Testing

Test #3: Lawrencetown Beach – Wind speed ~ 5.5 m/s gusting to 9 m/s – 75 psi pressure relief valve generates back pressure – Wind speed taken every 5 seconds – Volume water taken every minute – Wind speed nearly constant over rotor face

Results Average back pressure taken as 80 psi Able to determine efficiency based on theoretical kinetic energy of wind flux

Testing Optimum efficiency occurred near 4.7 m/s

Testing RPM optimized (steepest slope) around 5.3 m/s RPM is concave down above 5.3 m/s

Testing Turbine performed better than anticipated Flow rates approximately 50% higher than expected

Testing Test #4: Wind Tunnel Lab – Three wind speeds (low, medium, high) – 30 psi relief valve added – Flow rates recorded at 0, 35, and 75 psi – Volume water taken every two minutes – Air flow highly complex, uneven over rotor face – Analogous wind speed undeterminable

Testing Curve becomes more linear as wind speed increases Demonstrates higher flow rates at higher wind speeds

Safety - Hierarchy of Control 41

Budget 42

Budget 43 ItemCost Hub/Blades $ Gearbox $ Pump System $ Tower $ - Tail/Furling System $ Miscellaneous $ Testing $ Total $ 1,990.00

Design Requirements 44

Design Requirements 45 Design RequirementMet  Include an over-speed control system for the turbine to avoid catastrophic failure and ensure public safety. YES?  Be designed for constant operation in remote areasYES  Utilize pump components suitable for continuous contact with brackish groundwater. YES  Maximize flow rate to provide the most drinking water with the least amount of wind energy. YES  Contain little to no electronic components.YES

Design Requirements 46 Design Requirement Met  Be constructed of locally available and off the shelf materials. NO  Consider social implications of a wind pump installed in a remote, poor community. YES  Be able to respond to the intermittent nature of wind without interruption to the normal function of the system, i.e. no re-priming of the pump. YES  Require minimal human attention except for construction of the unit and regular maintenance YES

Design Requirements 47 Design Requirement Met  Pump water from a suitable brackish water table depth. This is the average water table depth in geographic location to be determined. YES  Pump as much water as possible at a minimum wind speed in the range of 3-6 m/s, with the objective of being usable in remote areas with low to medium wind resource. YES  Produce the minimum fluid pressure required for the filtration of brackish water. The design water pressure set by the civil engineering team is a minimum of 517 kPa (75 psi). YES

Acknowledgements Dr. Joshua Leon Dr. Graham Gagnon Dr. Alexander Kalamkarov Dr. Julio Militzer 48

49