An Antares motor glider is due to test fly a novel type of fuel cell by the end of the year, the first time a manned aircraft will have taken off and flown using only high-temperature polymer technology to generate power for the electric engine.
The German aerospace centre DLR and manufacturing partner BASF, together with Denmark's Serenergy, aim to evaluate the high-temperature fuel cell's potential for future electrical applications in commercial aircraft.
The DLR will head the integration of the air-cooled stack in the fuel cell system, whose novel polymer electrolyte membrane (PEM) technology is based on BASF's Celtec membrane electrode assemblies, while Serenergy will supply the stack. High-temperature PEM fuel cells operate between 120°C (248°F) and 180°C, need no humidification, require only a simple cooling system, offer a broad operating window and tolerate impure hydrogen, so could be sourced from on-board jet fuel reformation.
The technology needs further development and testing before installation, although the DLR says first test results demonstrate excellent performance even under difficult low pressure conditions.
"For us, we are only interested in using the motor glider as a flying testbed - we want to use it to fly different configurations, using different control strategies, and different fuel cell types," says Hans Müller-Steinhagen, the DLR's professor of thermodynamics and thermal engineering.
If the initial 750km (405nm) flight test - which will last up to 4h at up to 13,100ft (4,000m) altitude - proves successful, the novel technology could soon be flown on DLR's Airbus A320 flying testbed. Earlier this year Airbus scored an industry first by using that A320 to power an aircraft system with a conventional hydrogen and oxygen-based fuel cell that generated up to 20kW to power the aircraft's back-up hydraulic circuit, an electric motor pump and the ailerons.
A piloted, fuel cell-powered aircraft has also been flown by Boeing this year. The two-seat Diamond Aircraft Dimona motor glider, with a 16.3m wingspan, was modified by Boeing Research and Technology Europe, with a PEM fuel cell, lithium-ion battery hybrid system to power an electric motor coupled to a conventional propeller.
Flown straight and level at 3,300ft on fuel cell power alone for a maximum of 20min at a cruising speed of 54kt (100km/h), the aircraft used a combination of battery and fuel cell power.
Source: Flight International
