MTU Aero Engines, the German Aerospace Center (DLR) and GKN Aerospace Engine Systems are working together to enhance engine compression systems to reduce weight. The new technologies could go into the next generation of geared turbofan engines.

The work is part of the EU Clean Sky 2 programme.

A test campaign on the ICD rig has now begun at DLR’s site in Cologne. ICD stands for Inter Compressor Duct and is the name of the transition channel between the low- and high-pressure compressors. The goal is to fine-tune the interaction of the low-pressure compressor, ICD and high-pressure compressor to identify and leverage new potential for even more fuel-efficient engines.

An important step, MTU says, is the systematic mapping of the flow conditions in short, steep transition channels (ICDs). To achieve this, an entirely new wind-tunnel test rig was built at the DLR Institute of Propulsion Technology in Cologne, MTU’s Center of Competence (CoC) for propulsion systems.

Dr. Gerhard Ebenhoch, Director, Technology Management, MTU, commented: “This cooperation combines the partners’ respective strengths – GKN’s expertise in large static components, DLR’s experience in testing, and MTU’s expertise in compressors and systems – in an exemplary manner.”

Measurement technology

The ICD rig measures the channel flow in an “unprecedented depth of detail,” the partners say. Features such as 500 pressure tapping points, probe measurements at three traversal levels, and the use of laser technology and turbulence probes allow detailed insights into the flow mechanisms.

Dr. Gerhard Kahl, MTU’s Chief Engineer, Technology Demonstrators and Rigs, said: “By conducting these tests, we’ll certainly gain a much better understanding of the flow conditions in the ICD, the aim being to come up with particularly compact designs to further reduce the length, and hence the weight, of the engines in the future.”

Next steps

Three different ICD configurations will be tested over the course of next year. Based on the ICD rig test results obtained, a two-shaft test rig will be designed in 2019 and built in 2020. From 2021, the low- and high-pressure compressors will be tested together as one entity.