ALL ELECTRIC INTERCITY-AIRCRAFT DESIGN BASED ON FUEL CELL ENERGY SYSTEM

A possible way to approach an environmentally friendly design is to favour electric-based devices against their conventional counterparts in order to obtain All-Electric aircrafts and to power them by greener energy sources as hydrogen fuel cell systems. A preliminary design was carried out within the ENFICA-FC program (ENvironmentally Friendly Inter City Aircraft powered by Fuel Cells - EC funded project, 2006-2010, coordinated by Prof. Giulio Romeo) in designing an aircraft for 10-30 passengers in the intercity sector that is able to connect cities through flights while totally eliminating the environmental impact. The airplane works on hydrogen, taking advantage of the “fuel cell” technology available in short/middle term. Stacks with power density of 2.7 kW/kg are already available for research applications and they should be available in few years for real flights. Power converter greater than 5kW/kg had been already developed by Mavel PowerTrain company with a converter efficiency greater than 97% to enhance the efficiency of the whole system. With these future in mind, the aim of using zero emission propellers in the future to equip aircraft for 10-15 passengers in the intercity sector should be a real prospective and shall be shown in the paper. Although with slightly smaller performances a preliminary configuration was designed. An increase of 11.5% in take-off weight for the short technology readiness (about 2-5 years) and a reduction of 4.3% for the middle-term technology readiness (about 10 years) has been obtained with respect to a turboprop combustion engine configuration. The allelectric fuel cells Inter-City airplane is not in the same performance category (Range and maximum cruise speed) as the small commuter turbo-prop airplane. The range is decreased from 2300 km to 1600 km and the maximum cruise speed is decreased from 550 km/h to 320 km/h for short-term technology; a range of 2043km and maximum cruise speed of 353km/h for middle term technology; The electric-motor-driven two-seat airplane Rapid- 200, powered by fuel cells, was developed and validated by flight-test. Six test flights were successfully carried out by POLITO. The allelectrical power system was successfully tested during the experimental flights. Take-off and climbing was obtained at power of 35 kW. Level flight was attained at 150 km/h by mean of only a fuel cell power setting. 2.5 hours of effective flight were obtained during flight tests for a total path of 237 km. An high speed of 135 km/h and an endurance of 39 min was established during flights conducted for the FAI Sporting Code Category C (airplane).