1. Voice of the Engineer R15901: AIRBORNE WIND ENERGY BASE STATION

2. Background Airborne wind energy planes are designed to simulate the tip of the conventional wind turbine blade Operate at higher altitudes than conventional wind turbines Multiple methods to harness the energy Tether reel system Turbines on-board the plane conducted through tether Figure 1: Diagram showing swept areas of a conventional horizontal axis wind turbine(HAWT) and an tethered airfoil system.

3. Problem Statement Goals: ◦Design a Base Station that allows for continuous horizontal circular tethered unpowered flight ◦Implement a reel system to change the tether length during flight ◦Allow for rotation of the base station as the plane moves around the circle ◦Implement a bridle system to connect to the plane Stakeholders ◦Dr. Gomes ◦Professor Hanzlik ◦P15462 ◦MSD Office

4. Functional Decomposition Allow for continuous horizontal circular tethered unpowered flight Maintain Connection with ground Keep plane in horizontal circular flight path Maintain tether tautness Allow for full 360 degree tether rotation Connect tether to plane Connect tether to Base Station Change tether length Allow for manual control of reel system Allow tether tension to rotate connection point Rotate freely without slip Maintain constant bank angle during flight Evenly distribute tether tension load

5. Engineering Requirements rqmt. #SourceFunction Engr. Requirement (metric) Unit of Measure Marginal Value Ideal Value S1FDAllow plane force to rotate connection point Minimum tether tension required to rotate base stationlb51 S2FDMaintain constant bank angle during flightMinimum bank angle required for sustained flightdegrees1530 S3FDKeep plane in horizontal flight pathMinimum wind speed for unpowered flightmph105 S4FDChange tether length Reel system maximum feed rate ft/s35 S5FDAllow for manual control of reel systemMinimum torque required to rotate reel systemlb-in5025 S6CR Achieve continuous horizontal circular flight path Flight path diameterft6030 S7CR Achieve continuous horizontal circular flight path Maximum glider speedft/s80100 S8FDEvenly distribute tether tension loadMaximum tether tensionlb250500 S9CR Record videos of all flightsRecorded videos of all flights Binary Most flights recorded All flights recorded S10FDRotates freely without slipBearing friction coefficient for rotationN/A0.050.002 S11CR Achieve continuous horizontal circular flight path Duty Cycle of Propeller%500 S12FDChange tether lengthTime to make tether tautsec51 S13FDChange tether lengthTether lengthft S14CR Achieve continuous horizontal circular flight path Number of pilot inputs required to maintain flight pathCount155 S15CR Reel system to change tether length Power required for reel systemW52 S16CR Base Station with Tether Connection Weightlb2010 S17FDMaintain tether tautnessPercentage of flight with taut tether%7595 S18FDEvenly distribute tether tension loadTension Load per connection point to planelb20050

6. House of Quality

7. Concept Generation Brainstormed ComponentsConcept AConcept BConcept CConcept D (Current Method)Concept E Take-Off MethodStart TautStart slack and hand launchStart tautStart slack and hand launchStart taut Reaching AltitudeLasso Fly Straight up Lasso Reel System Method Automated DC Motor with gear system Automated DC Motor directly connected to shaft Switch to turn on/off and reverse direction DC Motor directly connected to shaft Reel by hand manually DC Motor powering gear system with maunal switch Reel System Connection Mounted to base station with metal plate Mounted at shaft endsGlued inHeld by team memberMounted at shaft ends Plane Tether Connection2-point bridle3-point bridleBall and Socket JointSnuggie Tether Rotation Implementation Allow reel system to rotateShaft attached to bearingsAllow reel system to rotateRotates without tracking Use circular plate with hole for tether mounted above reel system Base Station Ground Connection Metal stake in groundAnchor weight Use clamp that goes into ground Metal stake in ground MaterialsCombination of the threeSteelAluminumCombination of the three

8. Pugh Charts Concept A as Datum Selection Criteria Concept A (Datum) Concept BConcept CConcept DConcept E Cost -+++ Weight -+++ Time to Complete s+++ Capability of Reel System s--- Amount of Control Required by Pilot +--- Manufacturability ++++ Ease of Tether Rotation -s-+ Ability to Maintain Flight Path s--- Sum +'s2445 Sum s's3100 Sum -'s3343 Concept E as Datum Selection CriteriaConcept AConcept BConcept CConcept D Concept E (Datum) Cost--++ Weight-+++ Time to Complete---+ Capability of Reel System++s- Amount of Control Required by Pilot ++-- Manufacturability---- Ease of Tether Rotation-+-- Ability to Maintain Flight Path ++s- Sum +'s3523 Sum s's0020 Sum -'s5345

9. Risks  Feasibility Analyses Flight path not feasible ◦Perform analysis to prove that this flight path will allow for gliding flight Tether Tension too high for plane to maintain flight path ◦Perform calculations to ensure that tension never exceeds a specified limit ◦Develop a take-off method to avoid initial jerk of the tether going taut Plane is too difficult to control ◦Design bridle that will take away certain degrees of freedom to require less input from the pilot Wind Gusts too high for reel system to maintain tether tautness ◦Perform calculations to find the feed rate required of the reel system to maintain tether tautness

10. Next Steps Uncertainty and Questions: ◦Ideas for allowing rotation of the base station as the tether rotates in horizontal circle ◦Is it feasible to develop an automated control system for regulating tether length? ◦Should there be multiple projects running concurrently to develop the control system and base station? Moving Forward: ◦Meet with Professor Hanzlik and Dr. Gomes to discuss current progress ◦Perform feasibility analyses ◦Decide on resources for the project and number of projects

11. Questions?