ACARE (the Advisory Council for Aviation Research and Innovation in Europe) has set guidelines for the environmental impact of aerospace that target significant reductions in aircraft emissions. The ACARE targets for civil aircraft include NOx and CO2 emissions reductions of 80% and 50% respectively by 2020. Although airframes make a significant contribution, most of the balance (especially NOx) will be contributed by the engines. These contributions are expected to be achieved by lean burn, increased propulsive efficiency and increments in cycle efficiency via reduced component losses. Augmenting performance can be achieved by introducing new active controls to reduce off-design component efficiency loss, improve surge margin and lean-blow out margin. Unfortunately, current implementations are limited by the characteristics of existing electromechanical and hydraulic actuation devices (i.e. frequency response and cyclic life) and the high temperature, pressure and possibly liquid wetted operating conditions. Piezoelectric ceramics can overcome some of these limitations and offer the potential to make highly reliable actuation devices partially because the strain is developed without wear or friction.
AEROPZT will address the challenge of developing piezoelectric ceramics, encapsulation and actuator designs primarily for staged combustion fuel staging. The aim of AEROPZT is to enable pilot-main fuel staging without significant un-commanded thrust transients and reductions in surge margin (so called bumpless transfer). Another important application in the field of combustion is the control of thermoacoustic instability and lean-blow out. It is expected that the materials and technologies developed will have a wide range of other applications for active control within the engine such as active surge control, boundary layer control and active clearance control. The project work which runs from May 2014 to May 2016, is centred on the specific requirements of the SAGE 6 initiative; however the results are expected to have much wider applicability.
The objective of SAGE 6 is to demonstrate lean-burn as a whole engine system to a TRL6 maturity level. It is expected that the main focus of test activity for the integrated system will be concentrated on a new demonstrator vehicle based around and Rolls-Royce Trent 1000 engine suitable for installation on a flying test bed. Future builds of existing demonstrator engines such as the EFE and E3E and potentially experimental industrial platforms that use similar staging methodology will also be included into the programme.