SAE Powertrain & Energy - Prototype Issue - 23

Left: HyperMach believes its revolutionary allelectric hybrid engine will be a game-changer in that it will allow SSTs to fly unrestricted over land or sea, opening up boundless possibilities. The challenge is to convert highly innovative, outof-the-box physics into practical reality at an affordable cost.

would be replaced completely by electrical systems, with a hierarchical sensor systems architecture. The aerospace industry has been searching for a long time for a breakthrough technology that could deliver the power to restore the lost supersonic dream. This new concept could be the answer, but there is still a matter of developing the robust business plan to attract enough investment—and worldclass partners—to develop an aircraft and engine beyond the brochure stage. First flight is targeted for June 2021.

A ZEHST for life

Europe, through various strategic ACARE aims, has always had long-term plans for high-speed travel at some stage in the future as appropriate enabling technologies emerge. This is incorporated into the EC’s roadmap plan “Flightpath 2050.” In June, EADS presented a new concept study for a high-speed transport
SAE Powertrain & Energy

system that could fly up to 70 passengers on very long routes, such as from Paris to Tokyo, in less than 2.5 h while limiting the impact on the environment and being able to operate from standard runways (which would seem to rule out London, as its few runways will be totally full long before then). It would have a cruising speed of Mach 4 at an altitude of 100,000 ft. This new initiative is led by EADS Innovation Works and Astrium, in cooperation with the French national aerospace research laboratory ONERA and has seen the launch of a feasibility and systems study sponsored by France’s DGAC. It is partly a product of a French-Japanese cooperative supersonic technologies agreement signed at the Paris Air Show in 2005, between GIFAS and its Japanese equivalent, SJAC. Known as ZEHST (zero emission high supersonic transport), the concept definition draws on experience and data feedback from Astrium’s sub-orbital spaceplane project, and is one of the projects incorporated in EADS Innovation Works eCO2avia activities. These include efforts to demonstrate the feasibility of using biofuels and electric power for aviation purposes. The EC roadmap report sets the targets of reducing aircraft CO2 emissions by 75% by 2050, NOx reductions by 90%, and noise by 65%, compared to the levels of the year 2000. Progress toward building a real hypersonic transport would be achieved through risk-reducing development stages, starting with a small flying demonstrator before the end of this decade. The work currently under way is looking at how requirements and objectives can be aligned with the technical challenges. The concept would involve a mixed propulsion solution incorporating three different powerplants: jet engines, rockets, and ramjets. An initial ZEHST system concept is based on liquid hydrogen as the main fuel and is seen as the first step toward a basic reference solution. The next step will be to validate the environmental signature of the concept, and specifically its propulsion system architecture. The eventual choice of fuel will be decided in the light of environmental performance, but also its production and distribution. Energy management and the concept’s acceptance by the public, which includes potential passengers, will be studied as well. Tests and demonstrators will be essential in meeting the requirements of the program in the second phase. The third stage will see the development of a high-speed, “green” and quiet aircraft design for operation by 2050. According to Jean Botti, CTO of EADS, “The initial concept represents a propulsion system architecture that is driven by
Coming Jan. 25, 2012

SAE Powertrain & Energy - Prototype Issue

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