DAIMLER-BENZ Aerospace (DASA) is to go ahead with a programme to convert a Dornier 328 turboprop to a hydrogen-fuelled testbed late this year.
"The aim is to use the knowhow gained with the Dornier 328...for Airbus applications at a later date," says DASA. The project, now in the definition phase, is being funded by the German Government.
The German aerospace company says that the aircraft will initially have only one of its Pratt & Whitney Canada PW119B engines converted to hydrogen fuel, with the second to be converted later. The auxiliary power unit (APU) will also be hydrogen-fuelled.
Tests with a hydrogen-powered APU are being carried out "...with good results" at Aachen Technical College, in co-operation with AlliedSignal, Bodenseewerk Geratetechnik, DASA and Airbus.
The college has developed a new micromix combustion-chamber, with pre-mixing of the air and fuel before it enters the chamber, which promises very low nitrous-oxide (NOx) emissions, says DASA.
According to the company, experiments now under way at DASA's Hydrogen Centre in Ottobrunn, near Munich, have shown that large-cross-section combustion chambers can reduce NOx emissions to one-third of conventional-engine levels.
Eventually, levels as low as one-twentieth of present figures appear possible. The APU conversion for the demonstrator aircraft will be carried out by the College and AlliedSignal.
Since 1989, German firms led by DASA have been working on cryoplane technology together with Russian partners Tupolev and engine manufacturer Kuznetsov. Under a Russian Government contract, the Russian companies are to convert three Tupolev Tu-154s to natural-gas-powered testbeds.
DASA says that the technology for natural-gas power is close to that needed for hydrogen power, and that the Russian companies could build elements of the German demonstrator's fuel system.
Source: Flight International
