Lyman,
That is because your position is weak.

No, I do not understand your position.

The "extraneous data" are facts that you, for whatever reason, choose to ignore in attempt to reenforce your position.

I know this is a waste of time but, I will give it one more try. Simplistically, for the SR-71 mission, the engines required a level of thrust capable of flying at 80,000 feet and Mach 3.3. To achieve this, an engine had to be designed to provide enough initial thrust to propel the aircraft to a high Mach (~2.2) when a ramjet function could take over to accelerate and maintain a speed of Mach 3.3. To achieve this goal, the turbojet (generator for the ramjet) had to function as well as the ramjet, itself. However, there was a problem at high Mach with the turbojet compressor. The air in the compressor could stagnate causing compressor blade flutter or even compressor stall where the turbojet engine would cease to function at all. So the solution was to take excess air somewhere from the turbojet engine and duct it back to the AB (ramjet burner). This could be accomplished a couple of ways, pull air out as it entered the engine or pull air out at a convenient location in the turbojet compressor. So as to make the engines fit into the hole in the designed nacelles and not make them bigger in diameter adding weight to the aircraft, the latter solution was chosen. In doing so, it does not modify the basic definition of a ramjet or the ramjet function, in fact it enhanced it by providing more air for combustion when mixed with fuel. It is still a ramjet working with a turbojet or a turbo-ramjet engine. All the by-pass tubes do are to ensure the turbojet still works at Mach 3.3.

TD

You confuse nomenclature with theory...

I call my Tabby "Butterscotch".

Does that make her a dessert topping?

Some very embarrassing statements from somebody here.

First, best not to believe what you read on the internet.
All I can do is hopefully lead you to water.
Bob Abernethy's Untold tales is very good. It is too short unfortunately to explain much but we are in luck because we have the essential complement to his 'tales' in the form of the 'bible' he wrote on how he fixed the J58 to work at Mach 3.2. It is called US Patent 3,344,606.

Read the patent and then tell us what you have learned.
Read the patent and then tell us what you have learned.

Bear in mind 'Bob' designed and built real engines that made money. He didn't write textbooks.Read the patent and then tell us what you have learned.

Embarrassing statement
Embarrassing statement. Read the patent. Tell us what you have learned.

peter....

In the description portion of the patent, the author describes "Increasing Ram air temperature" as the drawback to high speed turbojet operation, then further, that the purpose of the bleed air is to cool the compressor then reinject the bleed into the ejector to be "reheated"...

My sense thus far is that rather than ennabling a Ram function, his purpose is to defeat it.....

The document resists copying, so I guess I could say:

Read the patent......

Continuing, the inventor actually suggests possible options to the turbojet problem. His "Option 3" he actually labels the "Turbo-Ramjet", which he rejects as too heavy. This option involves bypassing completely the Turbo machinery.

:ok:

I think this makes sense.
Too many classifications add no value . They require explanations. Just say what it is.
Engine A is a dual cycle. What does that mean? Well, above a certain speed it bleeds off some air.
Engine B is a dual cycle. Oh you mean... No! It's got variable stators...
Engine C is like a ramjet at high speeds. Right, that's because.... No It's got a spike like ramjet intakes. Oh, thanks.
J58? Just tell it like it is.

However there is an audience that wants classifications and intuitive 'understanding'.
KJ knew this (Discovery video for public consumption). Why didn't he call it a flow inducer on the program? Wrong audience. He saved that for "Our good friends at Pratt and Whitney do not like us to say that at high speeds their engine is only a flow inducer and that, after all, it is the nacelle pushing the airplane".

Exactly. He defines what a turboramjet is. He worked in the aero engine industry. He created a world beating engine. He didn't write textbooks or work at a think tank coming up with schemes and definitions that would never see the light of day. Some textbooks had the same definition BTW, eg Hesse and Mumford "jet propulsion for aerospace applications"' written by LTV engineers.

Don't understand, I'll read again.

Lyman, I can't find itWhat line?

Salute!

This is getting ridiculous about "names".

I have to agree with those here that do not think/believe the J-58 was in any way a "ram jet" once above 2.x M.

The clever engineers at Pratt figured out how to use all the air being crammed into the motor to use it in the burner. At the same time, they reduced some temperature and other bad things on the "core" engine. They also realized that you couldn't get a lotta thrust with a pure turbojet at the speeds they were trying to reach.

Had the J-58 been a combined cycle turbo-ramjet, it would have resembled the F100 that Pratt developed for the Eagle and Viper. An annular bypass, but a mechanism to close off most, if not all, air entering the core. The hot, compressed air from the intake would go directly to the "burner" section and act just as a traditional ram jet.

The J-58 did some of this, but the air being bypassed was nowhere near enough or hot enough to provide what is needed for a ram jet.

It should be noted that many of the early ( 1950 - 196x) turbojets had burners that could still add fuel to the unburned air that came thru the core. So the Pratt folks developed a way to bypass a lotta useless air and feed it directly to the burner and gain a lotta efficiency and thrust - up to a point.

A complete changover to a ram jet above 2.x M would have allowed the Blackbird a much higher speed/altitude, but the materials for the structure could not handle the heat. And the Blackbird did not have "thrusters" to control pitch, yaw and roll once really high - it was all aero forces on the control surfaces, shock waves and all.

The J-58 was a super motor, and it served us well for many years. But it was not a "turbo-ramjet".

That's my story, and I am stickin' to it.

Peter,

I assume the embarrassing statement from somebody here, you point out, are contributed to me, so I will respond accordingly. First about Dr. Bob Abernethy:

From his web site, Bob Abernethy.com:
Dr. Abernethy did indeed write a number of books and publications which are listed on his web site.
Bob didn't design and build real engines, he happened to come up with a solution to a problem that a real engine was having and it fixed that problem, making it a money maker instead of a money loser. Actually teams of people design jet engines, not one individual.
It is where I got the Abernethy/P&W patent some time ago but thought it might be too technical for some to fully understand. Also, Abernerthy's web site would be a source of information I would believe.
I've read the patent. You do know that patents are written to generally disclose the invention, but, not to give too much information away. A couple of things I will point out to you:
From the patent:
Actually, this would have solved the problem in the compressor which had two different problems, Stall and Choked, however, it happened there was patent for this feature: Us Patent 2,931,168 titled Variable Stator Engine Control System, Application Date - 5/24/1955, Patented 4/5/1960, Assigned to General Electric Company. You can easily hold the actuator arm in one hand and the piston controlling the arm in the other, not that heavy, and leakage is not a problem, Would have required modifications to the compressor casing and vanes, plus some time, but the patent was a problem.
From the patent claims:
I could go on, but I think you can see the information I provided is not embarrassing even if you may think so. I think Gums is right, forget the names, the engine worked and Dr. Abernethy had a great idea....

TD

Hi gums...

you say...."The clever engineers at Pratt figured out how to use all the air being crammed into the motor to use it in the burner. At the same time, they reduced some temperature and other bad things on the "core" engine. They also realized that you couldn't get a lotta thrust with a pure turbojet at the speeds they were trying to reach."

I was about to sit down and take four paragraphs to say just that. Clear, concise, in english.... :ok:

In the patent, a guy lays out the problem, offers options, and proposes a solution, making claims, and offers drawings and supporting material. I have been through it, and have a patent pending for a novel helicopter controls system.

For the record, the words "Partial Ramjet" are oxymoronic. A Ramjet is not a ramjet until a very specific point is reached, at which it becomes an engine, full on, no partial about it. It is either running, or it is not. It does not fill the role of "conttributory", as if it was some form of "Turbocharger".

Believe it or not, the Patent Office does not require a working prototype, or that the solution even work....

The inventor in question, here, Abernethy, calls his invention a bleed air recapture system.

He proposes the problem that all turbojets have, loss of power, efficiency, and off the chart temps, as it approaches very high Mach.

He says there are two causes, excess Temperature, and excess airflow, which "chokes" the compressor.

Both of these problems are....ready? Created by RAM AIR. So the problem is Ram AIR, too hot, too thick, and what do we do? Here he proposes to drain some bleed air from the fourth stage of the Compressor, which instantly unblocks the compressor (choke) and moves aft through the six ducts, to enter the Ejector, for added mass, and expansion.

This process also cools the compressor and Turbine, and the Ejector LINER, the case.


I am going back in to find the text where he identifies cooling function, and reheat.

back in a bit.......

from the PATENT (claims)...

"...my new engine provides cool bleed air to the afterburner for cooling purposes."

That does not sound like he is "turning the afterburner into a "partial RamJet".
As the "website" purportedly claims.

He specifically eliminates the nomenclature "RAMJET" as one of his"proposed" and ELIMINATED options. Number (3). "TURBO RAMJET", the name itself, is rejected by this man as descriptive of "his engine"...in hisown words (through his patent attorney).

But do read the patent, it is informative, seems to have cleared up some murk, and is pretty typical of Patent text in general.

cheers, Lyman

Turbine D,
I apologise for any misunderstandings. I felt that explanations like "the engine would be unable to cope with the volume of air" and "the air in the compressor could stagnate.." would not help people trying to grasp what was happening, whilst the patent explains the whole high inlet temp/low corrected speed problem correctly in a nutshell.
As you were suggesting these sources of information I got the wrong end of the stick.
Although you say the patent should not give much away, it seems an amazing first primer in compressor operation in general terms and more specifically at high inlet temps. Just seemed too good to not be made more visible.

I'm fully aware of Bob Abernethy's role as the 'father' of the M3 J58 ref my copy of Jack Connors book.and unfortunaley, again, was not on your wavelength. I have

Thank you for the variable stator story.
:\

Of course you are entitled to an opinion, but that doesn't make you correct.

In the adoption of the position that the engine featured no "ramjet" function, you need to explain,

Why Kelly Johnson, the aircrafts designer, refers to "ramjet"

Why the aircrafts pilots refer to "ramjet"

Why the aircrafts instructors refer to "ramjet"

Why the P & W engineer assigned to oversee the in service use of the engine refers to "ramjet"

Why the people assigned to command the operation of the aircraft refer to "ramjet"

Were all these people so stupid that they didn't know what they were talking about?

Abernethy is very specific about "Turbo-Ramjet". He introduces it as a potential approach to solve the problem of high inlet temperature and blocking, (choking) of the compressor. He describes it as heavy, utilizing 100 percent air flow from around, (bypassing) the core and unworkable.

As to "Partial Ramjet" I write above re: Abernethy utilizing the bleeds to "cool" the afterburner. By cool, he means a titch shy of melting. That does not describe a ramjet, and as I wrote above, a RamJet is an all or nothing concept, there is no "kind of" pregnant.

As to why the term "ramjet" became au courant in the fraternity, I can only guess. In the fifties and sixties, a Ramjet was a concept that was tantalizing, though the idea had been around since the early nineteen hundreds.

Abernethy does refer to "Ram Air" in passing, and defines it as the source of the problem for high speed supersonic turbojet propulsion... He describes it as too hot, and too dense, to manage through the compressor inlet,, it choked the compressor section, (not a stall, essentially the opposite), and prevented the turbojet from getting into seriously high speed regimes.

His resolution of the obstacles caused by 'Ram Air', got the attention of everyone, and though misunderstood, came into the jargon as "Ramjet", when in fact Abernethy specifically denied the concept in his patent....

So the J58 is not a Ramjet, not a Turbo Ramjet, and not a Partial Ramjet...

It is a "Recovered bleed air system"....

I think the misunderstanding perpetuated throughout the community as 'jargon' since it really wasn't utterly wrong, and had a cachet that fit the times, it leant myth and mastery to the fraternity, a fraternity that was in serious competition with Mercury, and Canaveral, for big dough, and bragging rights....

I don't particularly enjoy the pedantic role, but I love a spirited discussion....

:ok: great respect, Brian Abraham...

Well, we have a real problem on our hands, seems Bob Abernethy doesn't know what he's talking about.

I went out on a limb as to "partial ramjet", if that is accurate there is a "partial problem".

First, he did nullify the 58 as a Turbo Ramjet. That much is in the patent, unless he said something to contradict, elsewhere. It most certainly is not a pure Ramjet, that is obvious....as to "partial", I may be the only one, but I stand by my statement, there is no such thing.

If this "partial Ramjet" is working, from whence comes the Ram? If you answer "Bleed" then you put yourself in a corner, by definition, linguistically if not technically also.

The origin of inlet Air for a Ramjet is from the airstream. If it is mechanically enhanced, it does not meet the standard definition and is not a ramjet, partial or otherwise.

Abernethy describes this engine's inlet (J58) as being frustrated by "Ram Air".

The Ram creates high temps, and blocks the Compressor section.

So Abernethy reduces the temperature and block by decreasing the pressure at the compressor initial stage. At this point, having decreased the Ram, the bleed travels back to the combustor. The bleed has lower pressure and cooler temperature than the core gaspath and enters the afterburner, and becomes by definition only a Ram Jet? By decreasing pressure and cooling? That is the opposite of the standard mechanism for a Ramjet. Reducing pressure and temperature in the chamber describes ramjet?

Arse About....

I hate repeating myself. Bob Abernethy himself wrote.
You saying he doesn't understand what it was he patented? I'll repeat his partial quote in big letters

it converted the engine into a partial ramjet

I got it the first time. Put that aside and explain why my opinion is wrong....

His description is extensive in the patent, he adds mass to the ab and it is combusted, increasing thrust. The term partial ramjet does not appear...

How is that different from a standard turbojet. Can you explain?

And no, I am not saying he does not understand, only that I do not....

Abernethy's design introduces compressed air into a combustion chamber.

"A Ramjet has no mechanical compressor..." NASA Glenn Research Center

Lyman, I don't know why you continue to be so obtuse, and fail to understand what Bob Abernethy is saying. I'll spell it out for one very, very last time.

Bob Abernethy said it's a partial ramjet, but I called it a Recover Bleed Air engine on my patent

Confine yourself to that one statement. What part of it do you not understand?

Hi Brian

The disconnect is most clear. I have a point of view. The reality as I see it is the function, not the name.

The title does not matter to me so much as it matters to you.

To be Precise. The owner of the patent knows his work. He has assigned two titles to it. One title is informal, the other official.

I will continue to refer to it by its officially recognized title. I am less insistent in its title than in its function, which you seem to be disconnected from, as you refuse to discuss the machine on its merits.

I am not being unreasonable. I wish to discuss the function, the purpose, and the theory. The name has caused some interest in the discussion. At every turn, you jump in, get excited, and focus on the progenitor of the interest, instead of recognizing the worth of the give and take.

If I have been guilty of that, I apologize. I acknowledge the statement you make.

A Ramjet system has no mechanical compressor. A true statement. The argument should be about why Abernethy calls his invention a partial ramjet.

The tension should be between the official rule for Ramjets and the inventors apparent dismissal of it.

There be the treasure...

Be well...:ok:

Lyman,

To be precise, Abernethy did not "assign two titles" to his engine. He assigned a title to his patent, but said the engine was "actually", that is, in reality, a partial ramjet. I'll go along with that

Dick

Excellent point.....

Dick,
Brian helped us out earlier saying the J58 behaved like a partial ramjet at about M2 and above due to the 20% of its inlet flow having 4 stages of work and then bypassed straight to the afterburner.
From a pedants POV, can we consider a TF30, for example, at M2 with 50%? of its inlet flow having 3 stages of work and then bypassed straight to the afterburner also behaving like a partial ramjet? If not, why not?
Thanks
PK

When this thread started I was hoping for an interesting discussion about supersonic propulsion. Instead three pages are devoted to a heated discussion about who called what and why, debates about names when (it seems) the principles are not really understood.

Moving on...

Hi peter

Abernethy claims a twenty percent plus increase in thrust from the bleeds scheme. This augmentation is not only purposeful, but the system, by his desription, allows the engine to travel at 3M when it was essentially paying out at 1.7. So the engine, functionally, has two separate modes.

His lead in to the description of the challenge claims the problem was ram air, causing high temperatures and choking (blocking) of the inlet area. Now ram air is without doubt a precursor to a Ram System of propulsion, and the problems he describes present a possibility of utilizing this "problem" to accomplish ignition and sustenance for a true RamJet.

He also describes a Turbo Ramjet solution to the problem. For this, he proposes a true bypass around the core, not just bleeds, but dismisses the possibility as heavy and not workable.

I wonder if he was dismissive too early?

Are you aware of any work done to pursue this?

Your post above is compelling. When is a cucumber a pickle? At what point does Abernethy's "PARTIAL RAMJET" become a true RJ engine?

:ok:

Peter,

I shouldn't have done that. I had hoped to give Lyman pause to check his mass of verbiage for errors, contradictions, non sequiturs, pointless metaphors, et al. Instead I have unlocked another floodgate. I'm off.

Dick

Just happened to have put this in JB


http://www.pprune.org/jet-blast/5067...ml#post7666481

Leaving, instead of replying to peter? Too much pique, methinks, here....

Don't succumb to our resident concern troll.

Simply add them to your ignore list!

Through your User Control Panel: User CP, Settings & Options, Edit Ignore List. Then, type their name into the empty text box and click 'Okay'.

Folks, we appear to be getting off track just a little here. Please do keep in mind that the aim is to play the ball, not the player.

If one or more of our number adopt (a) hardline position(s) in respect of any particular point that should be noted .. and then we should move on.

Little in the way of useful outcome is achieved by belabouring such points.

I beg the indulgence of the forum if I took umbrage at Lymans continued insistence that I felt that once we could get Lyman to stop banging on with a fallacious argument the discussion could return to matters of fact, and teasing out why things might be as they are. I have a question of my own to follow.

peter kent provided the proof at post #12 that it is a "partial ramjet", and I pointed out that fact in my post #14. That particular posters are unable to accept iron clad proof I can only say they need to check their level of comprehension.

peter, re the 20 to 40% bleed figure. I came across the figure in a number of places, in particular one by Colonel Graham, so I give it some credence. Seems logical if you think about it, 20% when the bleed first opens at about Mach 2, increasing to 40% in the cruise as the increasing needs of the "ramjet" are met. I'll need to go back over the thread to tease out your other question/s that remain to be answered.

peter, edited to add re reduction in fuel flow with increasing speed.

Specific impulse is a way to describe the efficiency of rocket and jet engine. It represents the force with respect to the amount of propellant used per unit time. The higher the specific impulse the greater the efficiency. From the following ramjet formula you can see that the specific impulse (Isp) is directly proportional to Mach (Mo).

http://web.mit.edu/16.unified/www/SP...es/img1319.png

Lyman please check your "facts" before posting. Both here and the post you made in the general section as to why the 787 needs batteries are factually wrong.
You clearly are no specialist in aviation related matters which in itself is fine but accept the fact that others know more than you instead of arguing the toss

Hi Lyman,
I have to quantify partial ramjet in some more concrete terms just for myself first.
I would choose to focus on the rapidly diminishing but still remaining residual contribution of the compressor to the overall installation Pressure ratio.
For the SR-71 at cruise, Intake PR 38.8, engine PR 2.9, overall PR 112. Numbers from Peter Law's presentations on AEHS website.
The engine contribution still remaining is only 2.6% of the overall. It's almost a ramjet, unless the ramjet had not yet been invented in which case it's a turbojet at very high Mach number.
This definition also applies to the XB-70, for example. It must also be a partial ramjet.
This definition is, I think, intimated by Col Graham "the faster you flew, the more it became a ramjet, utilising the high mach air to augment the thrust of the engines."

However, since the generally accepted term, partial ramjet, applies only to the SR71 I have to, for my own piece of mind, try and understand the definition given by Bob Abernethy. I think it basically revolves around the same criterion, ie diminishing involvement of the compressor. But, instead of a gradual diminution from the compressor with rising flight speed, as in the above definition, we have a sudden diminution when the bleed is opened, but not because the pressure ratio contribution has suddenly dropped. Instead the flow has suddenly increased (see the patent maps) from bypassing some of the compressor. This map shows no significant change in PR and if it was significant to the story I'm sure it would have been highlighted as have all the other effects.

Using the term partial ramjet does not necessarily add value to the picture. After all, if the ramjet had not yet been invented we would say "it is an afterburning turbojet with bypass bleed" and it, by definition, behaves like one.

Since the ramjet has been invented and due to it's perceived extreme simplicity, it can be an aid to understanding and, I believe, that's why the term is so widely used. It's taken me a long time to come to this conclusion but at last have piece of mind. I am no longer irritated with the term.

Brian
20% is the right number because Bob Abernethy was quoting all his stuff at the design point. In the definitive memo, which really deserves framing on the wall (well mine anyway), he says "...at both Mach3 and Mach3.5 with 20% bleed." Not wishing to dismiss the 40% I would be interested in more details.
The Flight Manual information,I believe, shows just a 2 position Bleed, closed or open. Thus when open it was a fixed orifice and as such controls to pretty much a fixed percentage irregardless of the actual mass flows.

Hi peter...

Thanks for your response. I too had the wish to understand the inventor's explanation. The part on which I fixed was in his 'descriptions' and 'claims'. My takeaway was his solution to the problem as he stated it: 1) ram air caused excessive temps, and choked the compressor, functionally limiting its performance to mach 2 (or so). 2) bleeds that removed flow from the core reduced these unwanted temps, and in unblocking the compressor, ennabled the engine to increase its potential (his claim was twenty per cent, as you state)

I am unnable to copy the patent here, so please check my perceptions of the document?

You have read his claim that the bleed, escaping the rest of the core, (and combustion) was "cool, and utilized to cool the afterburner, and liner"?

My expertise is not technical; I have never tried to portray my skills as anything they are not. So I am remaindered in logic, reading, and a license to fly, which is in itself a license to learn.....

In his description of the invention, do you not see where a person might conclude that the inventor who has identified 'Ram' Air as a distinct 'problem' to solve would not likely then claim that he had invented a way to turn a Turbojet into an RJ? I did, so especially when he claimed cooling instead of heating, and flow, rather than compression, it seemed that a conclusion of "Ram Jet" was not in order.

I am in your debt, for your patience, and intellect shown in your response....

:ok:

and your restraint, in limiting your post to single color, and consistent font....

Peter,

I wasn't going to say anything whilst that stupid semantics argument was raging, but responding to Brian's plea to get back to teasing out a factual explanation of what might be going on and also returning to your original question that related, IIRC, to the effect of afterburner on the secondary induced flow I can offer a explanation based on the Concorde flow set up which, when you look at it closely, is virtually identical to the J58 set up i.e. the intake throat (trap ) bleed flow is passed over the engine as cooling air and then exhausted as an annulus around the primary convergent jet.

I'm no expert on the J58, but I cannot see any reason why the two flows should differ substantially.


For efficiency the secondary flow must be accelerated to supersonic conditions by the time it gets to the final nozzle exit. To my eyes the diagram of the J58 looks to be simplistic in this area because on Concorde at least there wasn't any appreciable mixing of the two flows.

Because it has to be accelerated to supersonic velocity the secondary air must pass through its own aerodynamic 'throat' formed by the expanded primary jet and the solid nozzle surface. The local Mach number at this point will of course be 1.0 and the secondary mass flow will be controlled by the available area at this point. This area will depend on how fast the primary jet expands and this is turn will depend on the pressure ratio between primary and secondary flows at the primary nozzle exit.

The net result (at least for us) was that there was a definite relationship between the corrected secondary mass flow (Ws.sqrt Ts) and the primary jet equivalent Wj.sqrt Tj. as shown on the diagram.

If I have it right, when you light up the afterburner keeping the primary jet exit area the same, the primary jet pressure doesn't change, the mass flow is increased slightly (5% ish?) by the addition of fuel, and the temperature rises substantially. On the cooling side the pressure doesn't change and the temperature will rise a bit because of the hotter jet pipe.

Taken together this means that the corrected mass flow ratio doesn't change much if at all, but because of the increased Tj the secondary mass flow will be increased. I think this is what you were getting at?

OK, if you want to be pedantic the secondary pressure at the nozzle will drop a bit because the starting pressure (intake bleed pressure)and temperature are unchanged but there will be a greater pressure drop through the engine bay as a result of the increased velocity.

If you want to be even more pedantic, when you get to Mach 3 with the spike shock on the lip the total intake capture will be frozen, so any increase in induced cooling flow will be accompanied by a reduction in flow through the engine, so Wj will drop and therefore Ws must drop etc. etc.

Hello Sir.

Can it be inferred that each discrete flow can be associated with ram effect, and turbo effect? Hopefully not a dumb question.

Thank you

The secondary flow doesn't get anywhere near the turbomachinery and any 'ram' effect is limited to whatever you get from decelerating the freestream flow down to Mach 1.0 and thence the static pressure at the intake throat bleed.

As to the primary flow I'm not going down that road again :bored:

So I think the answer to your question is "No"

I apologize, and thanks for the reply. I wish I hadn't been such a stubborn fool, I am starting to get what the inventor had in mind, and it intrigues me.

Thank you sir,

One last question CliveL?

I promise to stay away from primary flow. My picture is of two discrete zones, bound by streamline, in the nozzle? One, the primary, a circular section, bounded by a ring of secondary flow adjacent the Nozzle liner?

If they are discrete, and do not mix, can we call the secondary flow Ram Effect?

Also, since there is no fuel added to the Ram effect, and therefore no Ignition, can we actually call it a RamJet, partial or otherwise? If CliveL is busy, peter kent, can you help?

Lyman, my only J58 understanding comes from what I read. I can only learn from what other people offer in terms of explanations as well as questions.

I believe, although I can't find it, that it would say something more like "..reduced the effects of these unwanted temperatures" ie the compressor inlet temp was still the same.

This is only half the story. There are 2 distinct aspects to the bleed. It was required to sort out the debilitating way a compressor responds to high inlet temperatures ( the XB70 compressor used variable stators to do the same thing, I believe). Once taken it could not be allowed to go to waste so it was put back upstream of the afterburner. "without the afterburner the bleed air could not be heated to the energy level of the airflow and most of the increase in thrust would have been lost".

I couldn't find this.:confused:

Only by a gross distortion of the usual understanding of those terms. The secondary flow start life with some pressure above atmospheric by virtue of the intake shock system, but it only gets some fraction of the STATIC pressure at the intake throat and nothing whatsoever from the subsonic diffuser part of the intake. As I understand the term a ramjet cashes the temperature rise accompanying flow compression to give a sufficiently high temperature to provoke combustion of the fuel. The bleed flow gets nowhere near this condition.

No way the bleed flow can be regarded as any form of ramjet.

peter thanks for your time...

this: "Quote: when he claimed cooling instead of heating"


is an interpretation of his text where he claims the bleed air, being cooler, serves to cool the nozzle liner, and the afterburner section.

So I will go in to the patent, and locate by page and paragraph this part of the text.

I am using a google page of the original, it is an archaic font and jumps around when I sweep my screen.

My understanding of the device is that it is at least twofold, serving to "unchoke" the compressor, by relieving the compressor of the "block" and reduced compressor created temps. That is as far as I have gotten.

So you know, it is from that "understanding" that I derive an opinion, so both may easily be incorrect.

I'll be back, thanks for your help.

Also, having written patent language, for myself, (with my Attorneys) I am thankful for TurbineD's caution that Patent domain is tricky, one must explain enough to differentiate one's work from other similar work (known as prior art),
to prove "novelty", yet refrain from divulging data that makes one's proposal too "complete". Mystery is important. That is why Abernethy chose his title carefully.

Had he chosen "Ramjet Engine", he is open to rejection since it is not actually a Ramjet engne, and "Partial Ramjet" may not satisfy "novelty".

Also, as explained to me by my Attorney, a patent does NOT have to function to qualify for protection....or be in any way useful.

Hello CliveL

thank you for the response. I was hesitant to discuss Primary Flow. Since you brought it up, I can ask a question back?

you say..."No way the bleed flow can be regarded as any form of ramjet."

I do not expect to be excused, I behaved badly relative to nomenclature.

However, that is the point I was trying desperately to make. The bleed scheme is not Ramjet, nor does it create one, even partially.

I do not want to be a pest, so for now, I'll pause.

thank you again :ok: