The push to make engines cheaper and greener

 - November 29, 2006, 7:46 AM

Honeywell Aerospace’s new HTF7000 powerplant family promises “game-changing” progress on improving engine reliability and reducing operating costs. But the company is not stopping there. Under the leadership of advanced technology director Ron Rich, Phoenix, Arizona-based engineers are focusing on making advances in four particular areas: reduced acquisition and operating costs; more economical fuel consumption; improved power density (that is, better thrust-to-weight ratio); and reduced environmental impact in terms of both emissions and noise.

Rich told EBACE Convention News he is not expecting quantum leaps in any of those areas, but is confident incremental improvements can be achieved across the board. The results of his team’s labors could be applied to future versions of the TFE731 (which is expected to remain in service for two or three more decades), as well as in further iterations of the HTF7000 and, possibly, in a new powerplant dynasty that would likely be in a similar thrust class to the TFE731.

For example, Honeywell’s advanced technology unit (which employs a couple of hundred engineers) is working on smart controls for engine LRUs so components could be operated with greater use of electronics rather than the more maintenance-intensive mechanical hardware. It is also looking to simplify engine assemblies, combining several items such as new titanium blisks (a blade and disk). They also propose making greater use of dual alloy rotors currently used in auxiliary power units, and ultimately employing them in propulsion engines. These assemblies are both easier to build and to maintain.

Rich said an HTF7000 powerplant is currently being used to evaluate several new technologies, such as an advanced swept fan that can lower audible fan noise. He also said through its Tech 7000 program, Honeywell, which has an FAA-approved acoustic test facility, is looking at improved turbofan inlet and exhaust technology.

Meanwhile, ongoing performance improvement technologies are being significantly enhanced by analytical modeling and simulation techniques. The design fidelity of engine stage interactions will result in improved thermodynamic cycle efficiencies. The goal is to try to increase the stage loading and improve the efficiency of components without compromising safety.

Rich’s team has also developed a new advanced disk alloy–Alloy 10–a powder metal nickel-based alloy said to improve disk life, allowing for the higher stresses and temperatures that can boost the achievable power density of an engine. It also is exploring advanced turbine system cooling techniques.

In the domain of rotorcraft powerplants, Honeywell is halfway through a four-year program called “the small heavy fuel engine,” aimed at advancing the technology of the HTS 900 engine currently being developed for the Bell 417 helicopter. The first core test engine recently started running and the company expects to achieve a 50-percent improvement in the power-to-weight ratio, a 20-percent reduction in fuel burn and 35-percent lower life cycle costs. Rich said the program could prove to be the springboard for a new advanced turboshaft engine.