ADVENT core? Lower SFC

http://www.gizmag.com/ge-advent-hottest ... gas/26447/

The F101 (B-1B Bomber) and CFM56 engine shared a common core, except the CFM was designed for cruise flight in 737s, whereas the F110 went on to power the F-16.

With the talk about ADVENT core and being more efficient, is the bypass ratio optimal for a long-range high-subsonic cruise capable jet fighter?

At medium bypass ratios, I would still think it would be capable of afterburner thrust. Some of the Russian engines like the Progress AI-25 series are medium bypass (2.0?), and fly in trainers, but are a little slow to spool up.

The real question being how much of an improvement will an ADVENT core engine be over the F135? 15%, or more.. to justify the cost of developing into a production engine.

neurotech wrote:http://www.gizmag.com/ge-advent-hottest-jet-engine-less-gas/26447/

The F101 (B-1B Bomber) and CFM56 engine shared a common core, except the CFM was designed for cruise flight in 737s, whereas the F110 went on to power the F-16.

With the talk about ADVENT core and being more efficient, is the bypass ratio optimal for a long-range high-subsonic cruise capable jet fighter?

At medium bypass ratios, I would still think it would be capable of afterburner thrust. Some of the Russian engines like the Progress AI-25 series are medium bypass (2.0?), and fly in trainers, but are a little slow to spool up.

The real question being how much of an improvement will an ADVENT core engine be over the F135? 15%, or more.. to justify the cost of developing into a production engine.

The advanced engines, that are being worked on, should give the F-35 a 30% range increase, along with increased thrust, so yes, it's definitely worth the trouble.

[quote="wrightwing....The advanced engines, that are being worked on, should give the F-35 a 30% range increase, along with increased thrust, so yes, it's definitely worth the trouble.[/quote]

The F-135 is derived from the F-119, are these Advent design/ material advances applicable to the F-119 also?

neptune wrote:

wrightwing wrote:....The advanced engines, that are being worked on, should give the F-35 a 30% range increase, along with increased thrust, so yes, it's definitely worth the trouble.

The F-135 is derived from the F-119, are these Advent design/ material advances applicable to the F-119 also?

Materials? possibly. PW is working on a similar project of their own, as part of the Versatile Affordable Advanced Turbine Engines (VAATE) program which is likely more applicable to the F135/F119 engine technology, http://www.flightglobal.com/news/articl ... ar-374283/

P&W will demo a modified F135 with potential for more power/enhanced durability/greater fuel efficiency - - depending on user preference.

http://www.airforcemag.com/DRArchive/Pa ... -Burn.aspx

In for the Long Burn

Pratt & Whitney is gearing up for ground tests later this year of a demonstrator engine featuring technology that would increase the performance of the company's F135—the engine that powers the F-35 strike fighter, said Bennett Croswell, president of the company's military engines sector. The XTE68/LF1 powerplant, developed under Air Force Research Lab sponsorship, has "an improved hot section" compared to the F135 that would provide "about a 5 percent increase" in thrust if applied to the F135, Croswell told the Daily Report during an interview in Paris earlier this month for the Paris Air Show. Currently, the F135 is capable of 43,000 pounds of maximum thrust. If F-35 operators do not need the additional power, they could apply the new technology "to get better fuel economy" from the F135 or improve the engine's durability, he said. Building upon this work, the Navy is funding the company's efforts to reduce the F-135's rate of fuel burn by 5 percent, he said. These activities are examples of the technology-maturation projects in place to enhance the F135 over time, a similar model to how Pratt & Whitney continually improved the F100 over the years,

This might be interesting to some.

http://www.onr.navy.mil/~/media/Files/F ... CAT-B.ashx

neptune wrote:[quote="wrightwing....The advanced engines, that are being worked on, should give the F-35 a 30% range increase, along with increased thrust, so yes, it's definitely worth the trouble.

The F-135 is derived from the F-119, are these Advent design/ material advances applicable to the F-119 also? [/quote]
If they could get similar results with the F-119 (i.e. 10+% more thrust, 30% more range, more durability), the F-22's already stellar performance, would really be impressive. In any event, I look forward in the coming years, seeing what kind of performance improvements both planes see.

Remember the F119 was cutting edge 1980's tech. We have gone 20+ years, computer simulation and analysis is lightyears beyond what was available. I imagine that PW and GE have some much more knowledge and tech they could make a replacement for both the F119/135 with considerable more thrust and lower fuel burn. But who is going to pay for it?

The upgrades will give a better power plant, but a next gen power plant will make a leap forward. The F100/F101 we late 60's tech. The F119/F120 were late 80's. Buy time the next gen turbofans come online it will be at least 35 years from the F119/F120 generation.

The F101 core is in the CFM56, Technology from the F120 was added via the Tech56 upgrade in the late 90's. Now the CFM is getting the "Evolution" upgrade. Commercial tech is pushing ahead,

Once the military had all the greats computers, now we use COTS as they are more powerful. When the tech was new the military lead the way due to cost. Like the computer before it, the Turbofans are shifting toward the commercial operators in the lead. Yes it will be expensive to port it over to the military environment. But cheaper than doing it from scratch.

http://www.flightglobal.com/news/articl ... ig-390994/

Pratt & Whitney and AFRL start testing on adaptive fan test rig

Pratt & Whitney and the US Air Force Research Laboratory (AFRL) have begun testing with an adaptive fan engine test rig that is based on the company’s F135 afterburning turbofan found on the Lockheed Martin F-35 Joint Strike Fighter...

Next-generation adaptive fan engines will allow a fighter-sized afterburning turbofan to alter its bypass ratio for different phases of flight by using a third stream of air. For low speeds below about Mach 0.85, the third air stream will be used to increase the engine’s bypass ratio and boost its propulsive efficiency.

However, at transonic and supersonic speeds where high specific thrust is needed, that third stream will run through the core and increase the jet velocity of the exhaust. The third airstream can also be used for cooling the engine during especially demanding operations...

The results of the P&W adaptive fan rig tests will flow into the AETD programme, which has a stated goal of improving fuel consumption by 25% while providing a 10% increase in thrust compared with current fifth-generation fighter engines such as the F135. The navy’s FBR programme hopes to deliver a better than 5% fuel burn reduction on an F135 demonstration engine.

The jointly USAF and USN-funded adaptive fan test effort was launched in late 2011, with testing of the adaptive fan concept taking place from August through September 2013, according to P&W.

How long would it likely take before we could see such an engine in the F-35???

Corsair1963 wrote:How long would it likely take before we could see such an engine in the F-35???

"Not for the F-35

In reality, AETD is not delivering an engine. The deliverables for the three-year schedule are component rig tests, modeling and simulation, an engine ground demonstration, and an adaptive engine preliminary design.

Still, the program raised eyebrows and questions from Congress when the funding first appeared in the Fiscal 2013 budget.

"We just have gone through a multiyear battle here in Congress about whether we would build one or two engines for the Joint Strike Fighter," said Sen. Joseph I. Lieberman (I-Conn.), who questioned whether the Adaptive Engine Technology Development program was actually an alternative engine for the F-35. "I wanted to ask you flat out," he said to Wolfenbarger.

"No, sir, it is not," she replied. "It is a technology maturation program that takes the advances that we have seen under the ADVENT program and takes them to the next maturity level."

Wolfenbarger also clarified that the target 25 percent fuel efficiency gains can’t be reached by modifying any current engines."

http://www.airforcemag.com/MagazineArch ... gines.aspx

Unclear about exactly what platform will benefit from this technology development project, but the LRS-B is a likely first candidate due to its stage in development, and the Navy FA-XX. But to me it seems that the F-35 / F135 could benefit from some of the new technologies by the 2020's, and maybe a new engine in MLUs in the 2030s.

Corsair1963 wrote:How long would it likely take before we could see such an engine in the F-35???

I'm thinking the ultimate goal of all of these research efforts is to develop the propulsion system for the 6th generation of fighters and other future combat systems. It will merge the adaptive fan to the ultra-high OPR of the HEETE program as well as many other technologies.

maus92 wrote:[.. who questioned whether the Adaptive Engine Technology Development program was actually an alternative engine for the F-35..."No, sir, it is not," she replied....

A politician was involved and his lips were moving. That answer is for today's question and for today's planning.

Todate, the F-35 program has flown less than 100 jets out of maybe 3,000+. With maximum foot dragging the program will be less than 500 jets in five years (2018) , probably. In five years, you are "guaranteeing" that a reworked/ new jet with 25% better performance will not be considered? Probably it will, for the remaining 2,500+ jets.. In 20 years (2033) that new engine will be in 2nd generation and the F-35 will still be in production.

neptune wrote:

maus92 wrote:[.. who questioned whether the Adaptive Engine Technology Development program was actually an alternative engine for the F-35..."No, sir, it is not," she replied....

A politician was involved and his lips were moving. That answer is for today's question and for today's planning.

Todate, the F-35 program has flown less than 100 jets out of maybe 3,000+. With maximum foot dragging the program will be less than 500 jets in five years (2018) , probably. In five years, you are "guaranteeing" that a reworked/ new jet with 25% better performance will not be considered? Probably it will, for the remaining 2,500+ jets.. In 20 years (2033) that new engine will be in 2nd generation and the F-35 will still be in production.

Exactly, this will likely prove to be the biggest thing developed under Congress's nose since the Super Hornet.

The AETD program requires that the demonstrator engines be sized to fit the F-35 with "minimal modification." (and indeed P&W's engine is based on their F-135) Why on earth would you put a requirement like that into a technology development program? Just for fun?

Once AETD has demonstrated the feasibility of the approach the lure of a 25% savings in fuel, not to mention the increased thrust, reduced IR signature, improved high speed performance, reduced drag, etc, will be almost impossible to pass up. Someone will find the money to take one of these engines to production.

If this program meets its goals it will be the single biggest leap forward in engine technology since the first turbofans.

neptune wrote:

maus92 wrote:[.. who questioned whether the Adaptive Engine Technology Development program was actually an alternative engine for the F-35..."No, sir, it is not," she replied....

A politician was involved and his lips were moving. That answer is for today's question and for today's planning.

Todate, the F-35 program has flown less than 100 jets out of maybe 3,000+. With maximum foot dragging the program will be less than 500 jets in five years (2018) , probably. In five years, you are "guaranteeing" that a reworked/ new jet with 25% better performance will not be considered? Probably it will, for the remaining 2,500+ jets.. In 20 years (2033) that new engine will be in 2nd generation and the F-35 will still be in production.

It was the politically correct answer to the good senator from Connecticut which hosts P&W's head office. We'll see AETD-derived engines in F-35s sooner rather than later IMO. The economics alone will be too compelling.