Bringing Turbine Power TO SMALL AIRCRAFT

Turbines have been the propulsion engines of choice for large aircraft for many years, while small aircraft operators have had to be satisfied with piston engines, despite a desire for turbine power. The problem has been that low power turbines have unacceptable efficiency ratings of around 10 percent. Now, Turbotech S.A.S., a startup company in France, using ANSYS computational fluid dynamics (CFD) and structural simulation solutions, has patented a regenerative, high-temperature heat exchanger that increases the efficiency of low power turbines by a factor of 2-3. They achieved this by recycling what would normally be waste heat in the exhaust gases to preheat the air entering the combustor, resulting in less fuel required to generate the same amount of power. Turbotech views the turbogenerator as the “missing link” that will enable the future of hybrid-electric aeronautical propulsion.

While regenerative turbines are common for large land-based applications like multistage municipal power generators, compressing the design to make it compact and light enough to fit into a small aircraft without adding excessive weight was a challenge. One key to Turbotech's success was working with Le Guellec Tubes & Profilés, also in France, to develop compact, low-cost microtubes with sufficient strength and surface area to capture enough of the high-temperature waste heat and recycle it to the preheater. Another key was using ANSYS CFD and ANSYS Mechanical simulations for fluid flow, structural, and thermal analysis so they could test the designs virtually without having to build physical prototypes.