전투기 Re: Re: Re: 미군, F-35에 AETP 엔진 장착 포기, 코어 업그레이드 결정

[위종민]

https://www.airandspaceforces.com/air-force-skips-aetp-engines-for-f-35-presses-on-with-ngap/ 

F-35에 AETP 엔진 교체 계획을 포기하고 F135 엔진 코어를 업그레이드하는 쪽으로 결정났네요. 

AETP 엔진이 직경이 커져 F-35B/C에 장착이 가능한 지 불확실했던 게 가장 큰 이유인 듯 합니다. P & W의 주장으론 비용도 400억 달러 이상 들었을 거라고 하고요. 

업그레이드된 엔진은 2028년부터 제공 가능하다고 합니다. 

예전같으면 돈 많은 나라들은 XA-100 달린 F-35A를 주문했을 수도 있겠습니다만, 정비까지 다국적화된 기체라 그럴 일은 아마도 없겠죠... 

A GE Aviation diagram shows the three streams of airflow through and around the XA100 hot section. The third stream (in blue) can be put to work by diverting it, either by adding thrust or cooling the engine so it can run hotter, for longer. GE Aviation

Air Force Skips AETP Engines for F-35, Presses on with NGAP | Air & Space Forces Magazine

John Tirpak

6-7 minutes

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After a year’s deliberation, the Air Force has decided not to develop Adaptive Engine Technology Program (AETP) powerplants for its F-35s, deeming the cost too high in light of other demands.

Instead, the service will go with a suite of upgrades for the existing F135 engine and press ahead with the Next Generation Advanced Propulsion project meant to power its next fighter, Air Force Secretary Frank Kendall said in a March 10 budget briefing.

“We needed something that was affordable and that would support all variants” of the F-35, Kendall said.

The upgrades to the F135, deemed the “Engine Core Upgrade” by contractor Pratt & Whitney, will deliver improvements to the engine necessary to meet the demand for additional power and cooling on advanced Block 4 versions of the F-35. Those specific Block 4 requirements have not been made public.

GE Aerospace and Pratt both developed competing powerplants under the $4 billion-plus AETP program—GE the XA100 and Pratt the XA101. The two engines achieved improvements of 30 percent in fuel efficiency and at least 10 percent in thrust compared to the stock F135.

However, both powerplants used a bypass air system to achieve the gains, increasing their diameter. While the new engines would fit comfortably in the F-35A used by the Air Force, they would be more challenging to adapt to the Navy’s F-35C and very difficult to fit to the Marine Corps’ F-35Bs, which use a unique short takeoff/vertical landing system with swiveling exhaust nozzles and a shaft connected to a vertical lift fan behind the cockpit.

While GE insisted the AETP could be made to work with the F-35B, Pratt said it could not. And while GE claimed that the new engine would ultimately provide savings of up to $10 billion due to fuel savings and less maintenance, Pratt argued its analysis found the development and integration of the AETP engines with the F-35, along with changes to the worldwide F-35 engine sustainment system, would cost $40 billion over the life of the program.

“We’re pleased to see the President’s Budget includes funding for the Engine Core Upgrade,” a Pratt spokesperson said. “All F-35 variants need fully-enabled Block 4 capabilities as soon as possible, and with this funding, we can deliver upgraded engines starting in 2028.”

The ECU “saves billions, which ensures a record quantity of F-35s can be procured,” the spokesperson added. “It also ensures funding will be available to develop 6th generation propulsion for the Air Force’s Next Generation Air Dominance Platform.”

GE Aerospace was—predictably—unhappy with the choice, saying through its spokesman that “this budget fails to consider rising geopolitical tensions and the need for revolutionary capabilities that only the XA100 engine can provide by 2028.”

“Nearly 50 bipartisan members of Congress wrote in support of advanced engine programs like ours because they recognize these needs, in addition to the role competition can play in reducing past cost overruns,” the spokesman added. “The XA100 engine is ready to power U.S. warfighters today and in the future.”

The company also claimed the $4 billion invested in AETP technology thus far “risks being wasted if the program is ended so close to completion.” Congress, the company said, will ultimately decide whether the AETP is funded or not—the legislature previously directed preliminary work to take place ensuring that F-35 engines could be upgraded with AETP technology by 2028.

GE also said it is continuing to test and develop the XA100 “while pursuing funding support for 2024.”

The engine maker derided the ECU as “an incremental upgrade to the current F135 engines” that would “still cost billions, without providing the same capability improvements as the XA100. Other so-called savings you might see are cost avoidance numbers disguising an increased baseline cost.”

However, given that within the F-35 Joint Strike Fighter program, partners have to “pay to be different,” the Air Force would likely have born the entire cost of a new engine—leading to the decision to not proceed with AETP.

“This was based on the fact that the requirements were … applicable only to the Air Force,” and not “spread across the entire fleet of joint F-35s,” said Kristyn E. Jones, assistant secretary of the Air Force for financial management and acting service undersecretary.

“We’ve decided to move forward with the Engine Core Upgrade. We have $254 million in this year’s budget for that particular effort,” she added.

However, Jones said the money spent on AETP won’t go completely to waste.

“We do plan to leverage a lot of the capabilities that were part of the AETP prototype for efficiency, thrust … [and] thermal management, so it was not necessarily” a futile effort, she said.

“Those capabilities will be leveraged as we look at the next engines” under the NGAP program, which the Air Force seeks to fund at $595 million in fiscal 2024, up from $224 million enacted in the fiscal 2023 defense budget.

“We’ll be building on all the lessons learned” from AETP, Jones said, but she couldn’t offer a timeline of when test articles will be ready for that program.

The NGAP is intended to produce engines for the Next Generation Air Dominance (NGAD) fighter, the crewed centerpiece of a family of systems that is intended to provide air superiority in the 2030s. It isn’t clear how the NGAD development will proceed if its engines are being designed concurrently.

Deliveries of F-35s and F135 engines resumed recently after a two-month hiatus following an F-35B crash in December 2022. Pratt said it identified a “harmonic resonance” problem with the engine that only manifested after 600,000 hours of engine run time. The fleet has been directed to perform a retrofit in the field to correct the issue.

[백선호]

크... 직경은 F-35에 맞게 했으면 큰 사업 기회인데...

[위종민]

35B는 빼놓고 35C에만 용이하게 환장할 수 있었어도 결과가 달랐을 수 있을 것 같습니다.

[Minowski(김유철)]

블록4 내용보니까 레이더도 바꿔야하고, 17종의 새로운 무장도 인티해야하고 해서 AETP까지 벌이기는 비용이 감당못하는 것 같습니다. 일단 레이더 개량만 되도 J20에 비해서는 당분간 우위일거로 보이고...

[위종민]

레이더 등 전자장비 냉각능력이 부족하다는 게 이 업글 사업의 주요 동기였는데, 코어 업그레이드로 그 문제를 얼마나 해결할 수 있을 지가 관건이겠습니다.

[백선호]

영국에서는 컴퓨터가 워낙 열을 많이 내서 데이터 센터의 컴퓨터들이 내는 열로 수영장의 물을 데우기 시작했습니다. 디지털 보일러라고 부른다네요.

https://www.bbc.com/news/technology-64939558.amp

[위종민]

개인 PC CPU나 그래픽카드들도 고집적-고발열화되면서 하이엔드 CPU랑 글카 쓰려면 사제 수냉쿨러에 1kW급 파워 서플라이는 필수겠더라구요. 저도 파워 서플라이가 600W 짜리인데 글카 업한다면 받쳐줄 수 있을지 모르겠습니다.