The Leap 1, similar to nearly all the new generation of fuel-efficient turbofans, operates at higher turbine temperatures and has seen less operational time than anticipated due to hot section durability problems. This issue is especially pronounced for aircraft operating in areas with dusty or polluted atmospheres. A high-pressure (HP) turbine blade, designed to better tolerate these particulates, is now in the final confirmation stages.
Validation tests are set to continue throughout the year, accumulating a substantial number of cycles. "The changes have performed better than we expected," says Carlos Perez, General Manager of Service Engineering for CFM products, emphasizing the significance of the testing in achieving the maturity and operational levels of the CFM56.
Testing is taking place in Evendale’s Test Cell 40 where a Leap 1A engine is functioning alongside a specially developed dust ingestion rig. This rig, similar to the dust itself, has taken GE years to perfect, with initial ingestion testing for the GE90 commencing in the 2000s. Now, GE claims it can simulate the premature wear and tear and failure modes seen on the baseline Leap 1's first stage HP turbine blades.
The same dust testing protocol has also been utilized to validate improvements to the GEnx and GE9X engines. In all scenarios, including the latest Leap-1 tests, GE has employed heat transfer and computational fluid dynamics tools to scrutinize the revised design and to correlate it with service observations.
The dust, comparable to talcum powder, was specifically generated for the tests by geologists and chemists, and emulates particulate sizes and consistencies typically found in the Middle East and Indian subcontinent.
Following validation tests on the Leap 1A, which powers the Airbus A320neo family, GE and CFM partner Safran aim to conduct clearance tests on the Leap 1B, which powers Boeing’s 737 MAX, using the same upgrade. The enhanced HP turbine is expected to be implemented into new production engines as well as retrofits in 2024.
