"Flying Laboratory" To Help Develop Fuel Cell Technology For Aerospace Applications

The Antares DLR-H2, which is the world's first piloted aircraft capable of taking off using only power from fuel cells, did just that at Hamburg Airport Tuesday. Antares DLR-H2 has been developed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). The Antares flies with zero CO2 emissions and has a much lower noise footprint than other, comparable, motor gliders. The propulsion system for this aircraft was developed at the DLR Institute for Technical Thermodynamics (Institut für Technische Thermodynamik – Stuttgart) in collaboration with its project partners – Lange Aviation, BASF Fuel Cells and Serenergy (Denmark). This motor glider achieves new quality standards in the field of high-efficiency, zero-emission energy conversion and clearly demonstrates the progress that has been made in fuel cell technology.

Photo Credit: DLR

The centerpiece and greatest innovation on the Antares DLR-H2 is that it is powered directly by means of an ultra-efficient fuel cell. "We have improved the performance capabilities and efficiency of the fuel cell to such an extent that a piloted aircraft is now able to take off using it," stated Prof. Dr-Ing Johann-Dietrich Wörner, Chairman of the Executive Board at DLR. "This enables us to demonstrate the true potential of this technology, also and perhaps specifically for applications in the aerospace sector. Coupled with our expertise in fuel cell technology, DLR's many years of extensive experience in gaining official approval for aerospace systems are what made the Antares DLR-H2 a feasible proposition."

Photo Credit: DLR

The Antares DLR-H2 is based on the Antares 20E motor glider with a wingspan of about 60 feet, constructed by Lange Aviation, a company based in the Rhineland-Palatinate region of Germany. With its fuel cell propulsion system, Antares has a cruising range of 466 miles, or about 5 hours flying time. In order to accommodate the fuel cell and the hydrogen supply on board the aircraft, two additional external load carriers were slung under the specially reinforced wings. Due to the extra 220 pounds of payload that each of these removable and flexibly interchangeable containers is able to carry, the aeroelastic properties of the wings had to be reconfigured to prevent any adverse impact on the flight stability of the aircraft. Optimization work at the DLR Institute for Aeroelasticity (Institut für Aeroelastik – Göttingen) now provides the Antares DLR-H2 with an assured capability to fly at speeds of up to 186 miles per hour without any wing flutter. The current propulsion system permits maximum flying speeds of approximately 105 miles per hour.

Photo Credit: DLR

 The system uses hydrogen as its fuel, and this is converted into electrical energy in a direct, electro chemical reaction with oxygen in the ambient air, without any combustion occurring. During this zero-particulate reaction, the only by-product is water. If the hydrogen fuel is produced using renewable energy sources, then the motor glider genuinely flies without any CO2 emissions whatsoever. The fuel cell is slung under the left wing and the hydrogen tank under the right wing. The fuel cell system used to power the Antares delivers up to 25 kilowatts of electrical power. When flying in a straight line, the aircraft only requires about ten kilowatts of power. In this situation, the fuel cell is operating at an efficiency level of approximately 52 percent.

The total efficiency of the drive system from tank to powertrain, including the propeller, is in the region of 44 percent, making it about twice as efficient as conventional propulsion technologies based on combustion processes.

"The top priority in this project is of course the safety and reliability of the fuel cell propulsion system," stated Antares Project Manager Dr-Ing. Josef Kallo from the DLR Institute for Technical Thermodynamics. However, having the correct architecture for the entire system is just as important for full implementation of this project: "This includes having an absolutely reliable fuel cell, in conjunction with propulsion system of the aircraft and, last but not least, a fully mature configuration for the aerodynamics and aeroelasticity of the motor glider."

FMI: http://www.dlr.de