Andrew Doyle/LONDON
AN ADVANCED electronic engine-control (EEC) system, capable of operation in the high-temperature core of a jet engine, rather than being mounted on the fan casing, is under development by a UK consortium.
The project could lead to production of more-responsive and reliable EECs for civil engines, according to CSM Associates, which will carry out the research with Lucas Advanced Vehicle Systems Development. The EEC performs the central-processing functions of a full-authority digital engine-control (FADEC) system.
The main aim of the Hiteam project is to develop an EEC technology demonstrator capable of operating at temperatures of up to 200°C, and to test it on an engine (probably a Rolls-Royce Trent).
"Around 200°C is probably the upper limit for silicon-based electronic components," says Mike Manning, technical director at CSM. "Between 160°C and 200°C, we can satisfy around 90% of the requirements," he adds.
"There is a belief in the capability of electronic systems to operate at 200°C, provided that we get the design and build right. There are semi-conductors of a certain type and design that can take these temperatures."
Manning adds that to go above 200°C would be too expensive to justify the technical benefits. The current industry standard for FADEC electronics is 125°C.
CSM hopes that, if successful, the research could enable "intelligent" electronics to be integrated with engine actuators and fuel valves in the "hot" section of an engine. This could lead to development of more precise and responsive FADECs, with improved self-diagnostic and fault-isolation capabilities, and increased reliability and maintainability, while at the same time, eliminating the need for complex cooling systems.
Many processing and control functions would be delegated to individual actuator controllers, reducing the role of the EEC system to the overall coordination of a network of processors. This next-generation EEC configuration is known as a generic smart-actuator controller (GESAC).
"Because the processing is close to the sensors and actuators and we have a network, one feature is that if communication [with the GESAC] is lost, individual elements could operate locally," says Manning. Actuators would assume a "safe position", he says, allowing the engine to continue to operate.
The £1 million ($1.5 million) Hiteam project is expected to take two years to complete, and is being partially funded by the UK Department of Trade & Industry under its Civil Aircraft Research and Demonstration programme.
Source: Flight International
