MTU Aero Engines, a technology leader in brush seals

More than 30 years ago, MTU Aero Engines set out to develop its first brush seal. The innovative components are suitable for use not only in aircraft engines – as, for example, in Pratt & Whitney’s successful family of PurePower geared turbofans –, but also in steam and gas turbines, pumps and a variety of other mechanical engineering applications. MTU has established itself as a global leader in the field. The idea behind the technology of brush seals is as simple as it is brilliant: “The construction typically includes thousands of thin bristles forming a very flexible seal which continuously adapts to the moving surface to be sealed,” explains Benjamin Großkurth, who heads up brush seal production at MTU. This way, brush seals clearly outperform conventional sealing systems, such as labyrinth seals. Says Großkurth: “MTU’s brush seals reduce leakages by up to 90%, which boosts the performance of the engine or gas turbine.” Every increase in efficiency improves the eco-efficiency of a propulsion system, resulting in lower fuel consumption and reduced CO2 emissions. Take a single-aisle aircraft, for example. The innovative seals will save around 1% of the, say, 20,000 tons of kerosene the jet typically burns every year – and that is the equivalent of the amount of fuel carried by ten tank trucks with a capacity of 20 tons each. Moreover, CO2 emissions are reduced by the same percentage as fuel consumption. The latest example of applications that highlight MTU’s capabilities in the field of brush seals is the successful PurePower PW1000G series of geared turbofan (GTF) engines: MTU already contributes three brush seals each to the GTF engines to power Bombardier’s CSeries, Mitsubishi’s MRJ regional jet and Embraer’s E-Jets. Now the company has been selected to also supply its seals for the two additional GTF engine models: both the PW1100G-JM engine to power the A320neo aircraft and the PW1400G engine to power the Irkut MC-21 aircraft will incorporate a total of four MTU brush seals.