KiBox, the universal combustion analysis system, was mostly used for terrestrial vehicles in the past. But now it is literally soaring to new heights: as part of the development process for a new generation of aircraft engines, engineers from Continental Aerospace Technologies ventured up into very thin and cold air. And with the help of KiBox, they succeeded in optimizing the engines' performance.
More power and less fuel consumption – aircraft engines are expected to meet more or less the same requirements as those in automobiles. But conditions prevailing above the clouds are far from usual – making it more difficult to develop engines for the aviation industry. Continental Aerospace Technologies GmbH, which belongs to globally operating Continental Aerospace Technologies Ltd. ranks as one of the world's leading manufacturers of engines for small aircraft. The company operates facilities in the US and in Germany. Starting in the first decade of this century, the company developed its kerosene piston aircraft engine based on a diesel engine for passenger cars, with a redundant electronic control. This engine uses about 40 percent less fuel, so the range of the aircraft is extended by as much as 30 percent. This success was a quantum leap in innovation for Continental Aerospace Technologies, setting a new benchmark in the industry.
'As we continue to develop our engines, we literally want to soar to new heights!' The speaker is Dr. David Dörner, Application Engineer for Test and Application at Continental Aerospace Technologies GmbH. Some background information: as density decreases with altitude, air resistance is also reduced – so fuel consumption is cut. However, there are limits on the possibilities for flying high: as the aircraft gains height, the engine must increase its altitude performance so the plane will always have sufficient lift. Unlike large jets, engines in small aircraft have no turbocharging or only single-stage charging, so they have a much lower service ceiling (the maximum flight altitude in continuous operation). This is why optimizing altitude performance is such a key aspect of development.
To ensure that the engine also runs smoothly while the plane is descending from a high altitude and when power output from the engine is low, there must be sufficient compression energy for combustion to take place. Otherwise, the result can be what is known as flameout, which is similar to loss of flame in jet engines. Another requirement is the ability to actively turn the engine off at altitudes above 10,000 feet and then to restart it reliably – functions that cannot be taken for granted at temperatures in the high two-digit minus range: the decisive factor here is the reliability of the combustion process.