Revolutionary Technologies Group C1 Nicholas Arch, Nicholas Fraser, Robert Huth, Patrick Noble, Michael Toomey Preliminary Design Review February 7, 2008

Last Week’s Action Items  Decide between horizontal-axis and vertical-axis wind turbine Options: Lift-Based Vertical, Drag-Based Vertical, Traditional Horizontal Calculate power and torque  Use literature from Dr. Nelson  Complete torque calculations for available generators Analyze generator specifications Explore back-driven DC motor Calculate required torque using given generator

Vertical vs. Horizontal  Simplicity vs. Efficiency  Drag vs. Lift based designs  Varying wind conditions  Immediate weather response

Generator Selection  Basic torque requirement calculations  Generator vs. DC motor Generator is designed for constant power Motor is designed for torque

Torque Calculations LEGENDrho [kg/m^3]1.2 constantCd12.3 inputCd21.2 calculatedWind Speed [mph]15 importantWind Speed [m/s] TSR0.5 d [m]1 h [m]1.2 omega [rad/s] rpm rps V1 [m/s] V T [Nm] P [W] gear ratio10 T into gen rpm into gen Pwind [W] wind efficiency0.165 gear efficiency0.8 gen efficiency0.8 Pelec [W]

Current Status of Concept Status of Design Researching to decide best HAWT design Focus on: blade geometry shaft geometry wind shield counter rotating blades

Next Week’s Action Items  Individual Trade Study Proposal Finalize trade study assignments Perform Research to select design variables and tools to be used in the trade study  Complete Certification on tools Michael Toomey will get CNC certified Rob Huth will get Mill and Lathe certified

Thank You Questions?