DARPA Lifts the Covers on Vulcan Engine

DARPA Lifts the Covers on Vulcan Engine
Posted by Graham Warwick at 6/20/2008 8:58 AM CDT


If like me you are intrigued by DARPA's new Vulcan program to demonstrate a "constant volume combustion" (CVC) engine capable of powering a hypersonic vehicle from rest to Mach 4-plus, a few more details are now available at the research agency's website.

The industry day briefing begins with a review of the problem - how to accelerate a hypersonic vehicle from zero airspeed to the Mach numbers needed to fire up a supersonic-combustion ramjet. It includes a couple of interesting slides on the HTV-3X flight demonstrator conceived by Lockheed Martin's Skunk Works under DARPA's Falcon program.


Vulcan is the combination of a turbojet and a CVC, and DARPA says there are different ways to do that. One - called dual flowpath - has a common inlet and nozzle, but separate engines. The other - called annular - has one flowpath and the turbojet embedded inside the CVC. One challenge is that the turbine has to be cocooned above Mach 2 so it can survive the high temperatures in the Vulcan engine.
link for full article

I like it...but I am a bit puzzled.

NASA are leading the way on hypersonic engines with the use of magnetohydrodynamics, slowing mach 4 + air flow down to mach 3 so as to be usable with hypersonic aircraft... and now this 'dual inlet design..

This seems such a waste or duplication of efforts.. it leaves me scratching my head in wonder at just what they are trying to hide in this smoke screen of releases to the public.

Thanks for posting the pics, they are sweet.

Originally posted by Dan Tanna
I like it...but I am a bit puzzled.

NASA are leading the way on hypersonic engines with the use of magnetohydrodynamics, slowing mach 4 + air flow down to mach 3 so as to be usable with hypersonic aircraft... and now this 'dual inlet design..

This seems such a waste or duplication of efforts.. it leaves me scratching my head in wonder at just what they are trying to hide in this smoke screen of releases to the public.

Thanks for posting the pics, they are sweet.

You can only have so many people on a single project before it gets too crowded to really work - having competing projects means you have a lot more people working on the same problem but not getting in each others way.

reply to post by RichardPrice



Sorry if i didn't put that quite right.

NASA SOLVED this problem full stop. MHD device at the front and rear, with a conventional mach 3 capable turbine sandwiched in the middle.

Thus, letting the craft get to mach 8 +, with the MHD at the front slowing the air down so much that the engine thinks its only doing mach 3.

This then thrusts OUT into the rear MHD generator and the thrust is 'ramped up' to mach 8 / 9 / 10 + depending on what your doing.

Originally posted by Dan Tanna
reply to post by RichardPrice

 

Sorry if i didn't put that quite right.

NASA SOLVED this problem full stop. MHD device at the front and rear, with a conventional mach 3 capable turbine sandwiched in the middle.

Thus, letting the craft get to mach 8 +, with the MHD at the front slowing the air down so much that the engine thinks its only doing mach 3.

This then thrusts OUT into the rear MHD generator and the thrust is 'ramped up' to mach 8 / 9 / 10 + depending on what your doing.

Its hardly 'solved', its still a massively experimental technology and there could be other, easier ways to do it.

From everything I have read, MHD assisted turbines are still theoretical anyway - no one, including NASA, has built a working engine to demonstrate the theory.

So no, its not 'solved'.

NASA PDF first page

Lets just say that Dr Blankson in years prior to 2003 solved the math problem and designed the engine AND designed the wave rider craft to test it all out in...

He designed LoFLYTE, he solved the math, he designed the engines...all a while at NASA.

To me, thats all bar over, just need to build it all and bolt it together...

wait, stop, retrieving old aurora post to update...

www.abovetopsecret.com...



Lockheed Falcon... its just so Ironic..... actually.

www.designation-systems.net...

In August 2007, details of a Lockheed Martin Skunk Works program labeled HTV-3X emerged. Officially, it's a spin-off of the Falcon HTV program, and is also called Blackswift by some sources. The HTV-3X is apparently an unmanned reusable fighter-sized vehicle, which takes off and lands on a conventional runway and can reach a speed of Mach 6. The powerplant is reported as a turbojet/ramjet combined cycle engine

IT's far from just a "demonstrator". Look at the details from the thread from 2005.


[edit on 20-6-2008 by robertfenix]

[edit on 20-6-2008 by robertfenix]

[edit on 20-6-2008 by robertfenix]

[edit on 20-6-2008 by robertfenix]

????? wait stop what ??

Oh ill send you a u2u... didn't quite get what you mean.

Originally posted by Dan Tanna
NASA PDF first page

Lets just say that Dr Blankson in years prior to 2003 solved the math problem and designed the engine AND designed the wave rider craft to test it all out in...

He designed LoFLYTE, he solved the math, he designed the engines...all a while at NASA.

To me, thats all bar over, just need to build it all and bolt it together...

That's not solved. You can do as many math equations as you like, but until you actually TEST a real engine, it's all theoretical. Using your definition of solved, we would have bases on Mars right now and would be traveling the solar system.

reply to post by bdn12



Using my definition of solved all they have to do is build what he designed. Thats a chump change challenge to the MIC...

All they have to do for mars is get the will to build what they have designed... that however is not a chump change challenge... thats a few orders of magnitude greater that a airframe and engine.

The problem IS solved. All they have to do is build the systems.

(read through 1970's literature from senior hypersonic airframe designers... they say THEY solved this problem in the early '70s)

Building it doesn't mean that it works perfectly the first time. They've solved all kinds of problems in designs, built the system and it failed miserably. That's why they have test programs. Nothing is solved until they test the system and prove that it really does work.

Originally posted by Dan Tanna
To me, thats all bar over, just need to build it all and bolt it together...

And thats commonly the biggest problem - going to the moon was 'solved' in the 1960s, and yet it takes a larger investment today to repeat the matter than it took back then.

Originally posted by robertfenix
wait, stop, retrieving old aurora post to update...

When people start using the Aurora to back their claims up, thats the point at which I fall off my chair laughing.

VULCAN is a propulsion system demonstration program to design, build and ground test an engine capable of accelerating a full scale hypersonic vehicle from rest to Mach 4+. The VULCAN engine will consist of an integrated Constant Volume Combustion (CVC) engine and a full scale turbine engine. CVC engine architectures could include Pulsed Detonation Engines (PDE’s), Continuous Detonation Engines (CDE’s) or other unsteady CVC engine architectures. The CVC engine would operate from below the upper Mach limit of the turbine engine to Mach 4+. The turbine engine will be a current production engine capable of operating above Mach 2 and may be based on any of the following engines, the F100-229, F110-129, F119 or F414 engines. A key objective of the program is to integrate the turbine engine into the VULCAN engine with minimal modification to the turbine engine, to operate the turbine engine from rest to its upper Mach limit and to cocoon the turbine engine when it is not in use. It desired that both the turbine and the CVC engines share a common inlet and nozzle. It is envisioned that developing the VULCAN engine will enable full scale hypersonic cruise vehicles for intelligence, surveillance, reconnaissance, strike or other critical national missions.
link
This VULCAN program seems to be designed to expand the US Air Force portfolio of advanced airbreathing propulsion technologies, matured to the adequate TRL, to make the best possible choice when time is ripe to build a new generation of advanced recce/strike hypersonic vehicles.

To my understanding, exploratory research on advanced combined cycle engines -- I mean, a specific combination of turbojets and PDE, insofar as they (were thought they) could be used in the M= 0 / M= 6 segment, started in the late 1990s, receiving some visibility in year 2000 (kick-off papers by AFRL in this period). A decade or so passed. And insights inti the art of PDE progressed a lot.

VULCAN seems to be some sort of alternative to Nasa funded RTA (Revolutionary Turbine Accelerator) program. The fact is you would use conventional, off the shelf, turbojets in lieu of an ultra-advanced M4+ capable HiSTED type turbine engine. In other words, you'd want to LOWER the costs, maintenance type operations, development schedule and technical risks while besting performances.

VULCAN, however, appears to take a different approach. "A key objective of the program is to integrate the turbine engine into the VULCAN engine with minimal modification to the turbine engine, to operate the turbine engine from rest to its upper Mach limit and to cocoon the turbine engine when it is not in use," the announcement says. "It desired that both the turbine and the CVC engines share a common inlet and nozzle."

So, what's the final goal? "It is envisioned that developing the VULCAN engine will enable full scale hypersonic cruise vehicles for intelligence, surveillance, reconnaissance, strike or other critical national missions," says Darpa.

"It is envisioned that developing the VULCAN engine will enable full scale hypersonic cruise vehicles for intelligence, surveillance, reconnaissance, strike or other critical national missions," says Darpa.

So basically mach 4 to 5 cruise missiles.
How the hell will you shot one down in time.
Or trying to stop a harpoon type weapon over mach 4.
Recon aircraft at over mach 4.

Originally posted by Jezza

So basically mach 4 to 5 cruise missiles.
How the hell will you shot one down in time.
Or trying to stop a harpoon type weapon over mach 4.
Recon aircraft at over mach 4.

Weapons going at that speed would actually, theoretically, be easier to intercept as the faster you go, the more predictable your movements become as your manoueverability goes down (the SR-71 had a turning circle measured in several tens of miles).

Just send 20 or 30 low cost missiles up in a pattern infront and to the side of the weapon and they don't need to be going anywhere near as fast as the hypersonic weapon.

reply to post by Jezza



make it an unmanned low level evasive mach 4 harpoon type weapon and I think naval planners the world over will be having sleepless nights.

I'll hunt the links down for you, but I have an idea that instead of manouvering like an aircraft these mach 4 + missiles will 'bend' and 'roll' to evade intercept.

reply to post by Dan Tanna


Except that as Richard said, the faster you go, the wider the turn radius. It would take an SR-71 2-300 miles to do a 180 degree turn. Even an unmanned vehicle would take miles to make the turn. You're limited in the number of Gs that even an unmanned vehicle could take without structural failure.

reply to post by Zaphod58



You move a few feet side ways or roll out the way at that speed what evers trying to hit you will miss by a country mile. The old Granit with ram jets alone had a G limit of + 16... and how old is that ?

The Python air to air missile has a + 35 G limit... look i could keep this up all day dragging out g limits.. structual limits are easily within the limits of yesteryears technology, let alone todays.


RATTLRS ? A mach 3 ++ capable system for time critical responsive high speed strike. If the ONR think its viable and doable, I agree with them 100%.

I'll see if RATTLRS system has a small G limit 'cause its airframe cannot take the burden......

[edit on 21-6-2008 by Dan Tanna]

these kinda look alike.



that's all just wanted to say that. lol