Scaled Blade Design Model Blade Design Requirements Pitch

Scaled Blade Design Model Blade Design Requirements: • Pitch adjustability of +-0. 5 deg. • Trailing edge thickness of ~0. 1 mm. • Ability to operate in submerged environment. • Mass and CG to be evaluated for inertial match. Company Confidential and Proprietary

Scaled Blade Design Extreme Loads Design Point • • • TSR Rotor Speed 41. 975 Flow Speed Pitch -1. 504 Diameter # r/R Relm (m) Twist (deg) Chord (m) 0 1 2 3 4 5 6 7 8 9 10 8. 000 RPM 0. 500 deg 1. 820 m/s m Relative Thickness (t/c %) Absolute Thickness (m) 0 100% 0. 092 Thr/Len (N/m) Trq/Len (N) 0. 050 0. 046 23. 553 0. 092 100. 00% 0. 092 9. 1 0. 365 0. 150 0. 137 23. 553 0. 155 40. 00% 0. 062 37. 5 2. 784 0. 250 0. 228 15. 078 0. 218 8. 56% 0. 0186608 79. 3 5. 23 0. 350 0. 319 10. 558 0. 167 8. 56% 0. 0142952 111. 0 7. 286 0. 450 0. 41 7. 833 0. 134 8. 56% 0. 0114704 142. 7 9. 173 0. 550 0. 501 6. 032 0. 111 8. 56% 0. 0095016 174. 1 10. 904 0. 650 0. 592 4. 758 0. 094 8. 56% 0. 0080464 204. 4 12. 438 0. 750 0. 683 3. 812 0. 08 8. 56% 0. 006848 230. 6 13. 608 0. 850 0. 774 3. 083 0. 066 8. 56% 0. 0056496 242. 7 13. 763 0. 950 0. 865 2. 503 0. 042 8. 56% 0. 0035952 192. 1 10. 44 Company Confidential and Proprietary

Scaled Blade Design Company Confidential and Proprietary

Scaled Blade Design – Proposed Structure Company Confidential and Proprietary

Scaled Blade Design – Proposed Structure Basic structural analysis performed Company Confidential and Proprietary

Scaled Blade Design – Proposed Structure Basic structural analysis performed Using ABS • Stress level acceptable with 1. 35 Material Safety Factor. • Tip deflection of 29 cm is exceedingly high • Stiffer material required • Manufacturing concept pending Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Two methods of manufacture proposed: 3 D Rapid Prototype: • • • Accura 55 resin. 004” Build Layer Thickness (0. 102 mm) 1. 2 g/cc 58 -68 MPa tensile strength 3200 -3380 Mpa Modulus (per ASTM D 638) • Max stress ~22 MPa acceptable • Tip deflection of ~18 cm too large • Quote pending on cost • Potential to add spar or tube for stiffness Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Two methods of manufacture proposed: Compression Molded Composite: • Teflon-anodized aluminum die (x 2) • 17. 2 GPa Modulus • 172 MPa tensile strength • Max stress ~22 MPa acceptable • Tip deflection of ~1. 78 cm acceptable • Quote pending on manufacturing cost Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Navy-Carderock Suggested Method: Blade Material: Comp. moulded GFRP Tooling: Teflon-anodized aluminum mold Tolerance: Very good Deflection: OK Strength: OK Cost: High (tooling ~$40 K) Quotes in process for blades Very high quality and strength Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Direct Manufacturing 3 D Printing: Blade Material: Nylon (Laser Sintering) Tooling: Not required Tolerance: Acceptable (hand polish) Deflection: Problematic Strength: OK Cost: Moderate ($4. 7 K/blade) 3 -Part production with assembly. Potential for pultruded carbon spar. Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations True Ames Fin Company: Blade Material: CFRP VARTM Tooling: Low cost tooling Tolerance: Acceptable (. 1 mm) Deflection: Problematic Strength: OK Cost: Moderate ($4. 7 K/blade) 3 -Part production with assembly. Potential for pultruded carbon spar. Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Wooden Propeller: Blade Material: Laminated Wood Tooling: Direct milling Tolerance: Acceptable Deflection: Likely OK Strength: OK Cost: TBD Possible solutions for hubs as well from Ultralight aircraft ground-adjustable props Company Confidential and Proprietary

Scaled Blade Design – Manufacturing Considerations Two methods of manufacture proposed: Compression Molded Composite: • Teflon-anodized aluminum die (x 2) • 17. 2 GPa Modulus • 172 MPa tensile strength • Max stress ~22 MPa acceptable • Tip deflection of ~1. 78 cm acceptable • Quote pending on manufacturing cost Company Confidential and Proprietary