This was my presentation for my project that I completed for a Fuel Cell and Alternative Energy graduate level course that I completed.

1. PEM Fuel Cell for a RC Aircraft By: Rebekah Achtenberg

2. Background-The Plane Sig Kadet RC Aircraft Replaced the lithium-polymer battery pack with a Proton Exchange Membrane (PEM) fuel cell stack.

3. Background-The Motor Motor Data Maximum Power: 1500W Efficient Operating Current: 30-50A, 65A max 15 second Propeller Data 14 x 7

4. Fuel Cell in UAV In 2006, first fully fuel cell powered UAV 500W of total power Fuel Cell Stack 30V, 32 cells, 18.9lbs (8.6kg) Wingspan 21.6ft(6.58m) Length 7.8ft(2.38m)

5. Initial Concerns Weight distribution Fuel cells weigh more than a lithium-polymer battery pack Hydrogen tank and compressors are also required Area available for fuel cells and hydrogen storage Materials used have a lower strength than commonly used materials

6. Polarization Graph Use maximum power from engine and the maximum current to find an initial voltage needed Use polarization chart to figure out the area of cell needed and how many cells are needed

7. Hydrogen Storage Calculation Used an equivalent 2-stroke 5 oz. RC Engine Nitromethane was fuel, mf =0.17kg Stoichiometric Reaction a= 0.75, b= 1, c= 1.5, and d= 3.32 HC =-709kJ/mol QHV= 10920kJ/kg, HC (H2)=120.97MJ/kg Energy within gas tank=1.83MJ Since FC System is 2 times more efficient than a gas engine, only half of the energy needs to be used Mass H2 =0.91MJ/120.97=0.0075kg

8. Hydrogen Storage Specifications Hydrogen Storage Capacity: 9g Diameter:6.4cm(2.5in) Length:18.2cm(7.2in) 2.2lbs (1kg) Rated Discharge: 50W

9. Compressor System 2 Parker BTC miniature diaphragm pumps Run on 6V O.4lbs each 1/4in. Tygon PVC tubing

10. Lift Calculations

11. Power Calculations

12. Results and Suggestions For a Sig Kadet RC aircraft, using fuel cells alone does not work. Weight of additional fuel cell system is main reason for failure Using a battery in combination with a fuel cell Only need battery for takeoff and landing Use a more efficient propeller The more efficient the propeller, the less work the system needs to do Redesign of aircraft to be more suited for fuel cell use i.e. The fuel cell UAV was specifically designed for fuel cells and the design of the fuselage and wings accounted for this

13. Economic Concerns Fuel cells are extremely expensive and not as widely available Hydrogen Storage is also costly Lithium polymer batteries are readily available and comparatively inexpensive.

14. Any Questions?