When Honeywell announced at last year’s NBAA Convention in Orlando its intention to build the HTF10000, a 10,000-pound-thrust turbofan engine for super-midsize to large business jets, its Tech 7000 engine demonstrator was in test with a variety of technologies running. Over the past year, said Ron Rich, Honeywell Engines director of advanced technology, “We have torn that engine down and completed a series of performance, mechanical and accelerated endurance tests. We like what we’ve seen.”
The HTF10000 program is based on an HTF7000 engine with Tech 7000 development program technologies incorporated, Rich said. “We are now way beyond paper on all this stuff. Our 10K technology is flying now. We have started a core engine program for the 10K. Compressor, combustor and high-pressure turbine are in detail design, and we’ve begun to procure long-lead components such as forgings.”
He said the HTF10000 core engine will run late next year. A series of rig tests will be used to evaluate various components in the interim.
Among subsystems for which tests have been completed as part of Tech 7000 is a new quiet high-speed fan design. “The next step,” said Rich, “is ingestion testing next year where we’ll be shooting a bird at it.” He added that Honeywell has finished running one of its new compressor impeller technologies, which uses dual-alloy composition with two different materials joined together. “Traditionally, impellers are made of only one material,” Rich explained. He said that combining two alloys provides increased cyclic life and an ability to run at higher speeds and temperatures.
By incorporating Tech 7000 advanced technologies into the proven HTF7000 engine, Rich said, Honeywell aims to “ensure that we have a robust technology suite ready to go. We are now flying one of our Sabre (single annular combustor for reduced emissions) technology, which incorporates a low-emissions combustor. We have completed a series of sea-level tests for that new combustion system, now flying on our Boeing 720 to assess high-altitude performance characteristics. It is performing well and we’re very encouraged by what we’re seeing.”
Rich said the size increase to reach the 10,000-pound-thrust target from the HTF7000 is actually quite small. “For example, the low-emissions combustor, which will be scaled up slightly for the 10K, involves just a small physical change,” he said. “This is why we feel so confident about streaming our Tech 7000 work into the 10K.”
Rich added that Honeywell engineers are starting to gather hardware for the next phase of the Tech 7000 program. “Right now,” he said, “we’re focusing on the high-pressure turbine incorporating a new disc alloy, Alloy 10, in the high-pressure disc, and introducing thermal barrier coating along with a number of other innovations. There is hardware and it’s flying now.” Regarding potential applications and airframe competitions, Rich noted, “We have been talking to all the OEMs and finding that there is a lot of interest.”