It’s August 2016, and the US Military has granted GE and the Superior Turbine Engine Firm – a three way partnership between Honeywell and Pratt & Whitney – 24-month contracts to take their proposed engines for the Boeing AH-64 Apache and Sikorsky UH-60 Black Hawk navy helicopters by way of preliminary design overview. By April 2018, it’s time for demonstrations.
One of many key necessities of the contract, along with energy will increase of, say, 50%, and gas consumption reductions of, say, 25% was that the brand new engines match inside the present airframes. To efficiently validate its engine design match accurately within the helicopters, GE leveraged its polymer 3D printing lab at its Additive Know-how Middle (ATC) in Cincinnati to develop a printed prototype of its T901 engine true to measurement.
GE’s T901 engine contains quite a few technological developments that had been efficiently demonstrated on this rig and engine testing part, which led the US Military to award GE with a 517 million USD contract that may permit it to flex its metallic additive manufacturing (AM) muscle as soon as once more. Engineering and manufacturing of a number of additive metallic T901 engine parts is progressing nicely. The primary improvement engine ran in 2022 and the primary flight check engines are actually scheduled to be delivered by the autumn of 2023.
In March, on a tour of GE Aerospace’s ATC in Cincinnati, TCT was given some context behind the T901 AM purposes for the Apache and Black Hawk platforms. Right here is GE Aerospace’s AM journey, utility by utility.
The primary FAA authorised 3D printed half
“It began with this one half,” is the road GE likes to make use of to seek advice from its 3D printed LEAP gas nozzle tip. And whereas this tip – with its 25% weight discount and 30% value effectivity improve – did kickstart the corporate’s additive manufacturing voyage, it was the short turnaround of the GE90 T25 sensor housing that introduced the primary FAA-approved 3D printed half eight years in the past.
The half wanted to bear a redesign, so the ATC was enlisted to make use of additive manufacturing to shortly develop and industrialise a brand new resolution. Ten components had been consolidated into one, and 12 items had been printed in a single construct. Roughly 400 of those parts had been manufactured and put in on the GE90-94B engines.
Over 180,000 3D printed LEAP gas nozzle suggestions have now been shipped, with 1,000 items manufactured each week at GE’s Auburn manufacturing facility.
“We would have liked to do it shortly and be capable of iterate quick, which is why we used 3D printing,” ATC Website Chief Chris Philp says.
Warmth exchangers
After enhancing the T25 sensor housings, related design ideas had been shortly utilized to warmth exchangers, with vital reductions utilized to half meeting, measurement, weight, and value. On the GE9X engine, for instance, GE has integrated an aluminium F357 warmth exchanger manufactured on the Idea Laser M2 that’s 40% lighter. It additionally boasts a component consolidation of 163 historically manufactured parts right into a single printed piece.
“A [conventional] warmth exchanger has loads of tubes welded collectively and we have 3D printed it as a strong physique,” Philp explains. “So, it is much more sturdy and has much less supply of failures.”
A brand new utility
Having proved to the FAA it may additively manufacture dependable plane components, GE was buoyed. Because it stepped into its GE9X engine platform, it noticed the chance to leverage 3D printing in its new engine. The group determined to use additive manufacturing to a flowpath part, that might in any other case not be produced conventionally inside the constraints of the engine.
In doing so, GE designed a cyclonic inducer part which makes use of centrifugal forces to ‘divert particles of mud to the surface of the flowpath, earlier than being ingested into the primary stream, bettering sturdiness,’ per Philp.
GE was so assured within the additive design of this part that it had developed its engines with the half in thoughts earlier than FAA certification was granted. This part is manufactured on the Idea Laser M2 system in a cobalt-chrome alloy and has been consolidated from 13 components into one. It is usually mentioned to be twice as sturdy as earlier than. Eight 3D printed cyclonic inducers are fitted to each GE9X engine.
There are plans to re engine round 1,300 Sikorsky UH-60 Black Hawk helicopters and 600 Boeing AH-64 Apache helicopters. Every helicopter has two engines.
Low strain turbine blades
As beforehand detailed in TCT Journal, GE can be having success with the Arcam Electron Beam Melting (EBM) know-how. A complete of 228 low strain turbine blades are being additively manufactured on the Arcam EBM A2X in titanium aluminide for every GE9X engine. These parts are contributing to an improved gas effectivity of 10% and are 50% lighter than their historically manufactured counterparts. Due to the EBM course of elevating the temperature inside the machine to 1,200°C, there are smaller thermal gradients generated and the parts expertise much less residual stress through the construct.
One engine – zero tolerance to failure
GE has additionally thrown 3D printing at its Catalyst engine for the single-engine Cessna Denali plane. And it’s right here the place its utility of additive will get greater and extra advanced.
“We actually took a recent strategy to design this engine. That is the following step up,” Philp says.
Within the additive manufacture of the turboprop engine parts, GE has integrated built-in airfoils into the interiors of engine parts to facilitate higher efficiency. The engine can be mentioned to burn as much as 20% much less gas and obtain 10% extra energy than different engines in the identical class. Among the many components printed for the Catalyst engine are a complicated turboprop gas heater, exhaust case and C Sump part.
T700/CT7 midframe
“This is likely one of the hardest components nonetheless to make, and we’ve been making it for 35 years,” Philp notes of the T700/CT7 midframe.
GE prototyped an additive model of the CT7 midframe, once more, specializing in half consolidation. One of many weight-saving alternatives it had recognised was to consolidate components in order that it may take away flanges, nuts, and fasteners in a bid to assist save weight, and so it may take away the ‘very difficult’ welding, brazing and meeting of components. Within the improvement of this prototype, which was subsequently validated on a improvement engine, GE integrated 3D printing as a lot because it may, with the efficiency ‘exceeding expectations’ of earlier iterations of the engine.
Philp suggests the work carried out to additively manufacture bigger, extra advanced parts just like the CT7 midframe has helped the corporate to land the T901 contract, inside which GE has at present printed and examined additively manufacture parts for use in engine qualification and flight testing.
“We use these classes realized, that information [from previous projects], to say ‘perhaps we took it a bit too far, let’s pull it again a bit of bit.’ What you see listed below are all parts for brand spanking new engines, and that’s actually the place we see essentially the most bang for our buck in 3D printing,” Philp says. “It’s not simply saying I can change this one half in an engine – that sensor housing was a separate story – if you begin to design the engine as a system, with all the advantages of 3D printing, that’s if you acquire the efficiency, weight and gas financial savings.”
