[books] aircraft and engine

[Élodie]

Dear all,

I've just published my books : one about aircraft characteristics, and
another one about turbofan and turbojet engines. May be they could interest
you, that's the reason why I leave this message.

I'm glad to present you :

Title: Avions civils à réaction : plan 3 vues et données caractéristiques
Abstract: This book shows the characteristics of about 1500 aircraft
equipped with turbojet or turbofan engines.
It deals with airliners, freighters, business aircraft, ...
In order to make this book easier to use, aircraft specifications are shown
in the same synthetic way: 3 view drawings, dimensions, mass data,
powerplant, and performances data (with the payload-Range diagram).
http://www.elodieroux.com/EditionsElodieRouxAvions.html


You should also discover my other book about aircraft engines.

Title: Turbofan and Turbojet Engines: database handbook
Abstract: This book is a collection of the characteristics of about 1500
turbofan and turbojet engines, with or without afterburner. These engines
are implanted on many kinds of aircrafts: airliners, freighters, business
aircrafts, fighters, experimental aircrafts, gnopters...
In order to facilitate the use of this book, engine characteristics are
shown in the same synthetic way: thrust, specific fuel consumption, engine
weight, bypass-ratio, overall pressure ratio, turbine entry temperature ...
http://www.elodieroux.com/EditionsElodieRouxEngines.html
This book is also available in French.
http://www.elodieroux.com/EditionsElodieRouxMoteurs.html

If you would like to better discover all books published by Elodie Roux
Editions, some extracted pages are available on: www.elodieroux.com

Best regards,

Elodie Roux.

[Ron Hardin]

Élodie wrote:
>
> Dear all,
>
> I've just published my books : one about aircraft characteristics, and
> another one about turbofan and turbojet engines. May be they could interest
> you, that's the reason why I leave this message.

I've always wondered why the exhaust doesn't just blow out the front,
in jet engines.

--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Élodie]

what do you mean ?

[Ron Hardin]

Élodie wrote:
>
> what do you mean ?

Well, you've got this combustion chamber, and you add fuel, and
ignite it.

It's open on the front and the back.

Why doesn't the combustion product simply blow out the front and
the back both? Leaving you sitting on the runway exactly where
you started.

The buzz bomb solved this in the only sensible way. The vanes shut
and then you blow up the fuel. So the Germans saw the problem.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Darrel Toepfer]

Ron Hardin > wrote:

> Well, you've got this combustion chamber, and you add fuel, and
> ignite it.
>
> It's open on the front and the back.
>
> Why doesn't the combustion product simply blow out the front and
> the back both? Leaving you sitting on the runway exactly where
> you started.
>
> The buzz bomb solved this in the only sensible way. The vanes shut
> and then you blow up the fuel. So the Germans saw the problem.

Starter motor (electric or otherwise) starts the blades spinning to get
the sucking and blowing cycle geauxing... Don't introduce fuel and
ignite it until adequate RPM's are established...

<Quote On>
The process for starting a gas turbine engine is a complicated procedure
which requires continual monitoring of various engine parameters to
avoid damaging engine components. One potentially damaging condition
which may arise during engine startup is a hot start. The exact cause of
a hot start condition in a gas turbine engine has been the subject of
much speculation and theory, however, the detection of the occurrence of
a hot start condition is well known.

A hot start condition occurs when the temperature of the working fluid
exiting the turbine section of the gas turbine engine exceeds, by a
certain amount, the expected exhaust gas temperature schedule for the
engine during a normal startup. As will be appreciated by those skilled
in the art, an unaddressed hot start condition can cause the gas
temperature in the turbine section to exceed allowable material
temperature limits, thereby shortening or ending the life of internal
engine components such as blades, disks, seals, etc. Typical engine
starting procedures therefore call for careful monitoring of the exhaust
gas temperature, and immediate shutdown of the startup sequence should
exhaust gas temperature exceed the appropriate limit.
<Quote Off>

MediVac helicopter pilot had a bad day here at the local airport awhile
back. Landed for refueling and then toasted one engine on restart.
Couple days later, they replaced the engine (and probably the pilot) and
left...

As I am told, Garret engines are cheaper but more prone to hotstarts.
Computer control has made it more foolproof, but also more costly...

The History of Engines - How Engines Work
Part 2: A Short History and Timeline of Gas Turbine Engines
http://inventors.about.com/library/inventors/blenginegasturbine.htm

[Ron Hardin]

Darrel Toepfer wrote:
>
> Ron Hardin > wrote:
>
> > Well, you've got this combustion chamber, and you add fuel, and
> > ignite it.
> >
> > It's open on the front and the back.
> >
> > Why doesn't the combustion product simply blow out the front and
> > the back both? Leaving you sitting on the runway exactly where
> > you started.
> >
> > The buzz bomb solved this in the only sensible way. The vanes shut
> > and then you blow up the fuel. So the Germans saw the problem.
>
> Starter motor (electric or otherwise) starts the blades spinning to get
> the sucking and blowing cycle geauxing... Don't introduce fuel and
> ignite it until adequate RPM's are established...

Of course, the exhaust blowing out the front turns the turbine backwards,
and the exhaust blowing out the back turns it forwards. You're where you
started, in explaining it.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

[[email protected][_1_]]

On Tue, 05 Jun 2007 21:11:46 GMT, Ron Hardin >
wrote:

>Of course, the exhaust blowing out the front turns the turbine backwards,
>and the exhaust blowing out the back turns it forwards. You're where you
>started, in explaining it.

If this is a serious question, it may have something to do with the
fact that more of the energy produced by burning the fuel is used
driving the compressor than is used for propulsion.

TC

[Ron Hardin]

wrote:
>
> On Tue, 05 Jun 2007 21:11:46 GMT, Ron Hardin >
> wrote:
>
> >Of course, the exhaust blowing out the front turns the turbine backwards,
> >and the exhaust blowing out the back turns it forwards. You're where you
> >started, in explaining it.
>
> If this is a serious question, it may have something to do with the
> fact that more of the energy produced by burning the fuel is used
> driving the compressor than is used for propulsion.
>
> TC

Well actually I know the answer, but I've never seen it explained.

(That's as to its being serious. But an unexpected mystery is always
serious.)
--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Darrel Toepfer]

Ron Hardin > wrote:

> Of course, the exhaust blowing out the front turns the turbine backwards,
> and the exhaust blowing out the back turns it forwards. You're where you
> started, in explaining it.

Doubtful...

The starter motor spins it in a set direction. You'd have to reverse the
polarity, if electrically driven...

The only fear is that of a "hot start" which has already be explained. Or
perhaps if you had a massive tailwind and no means of turning the plane
into the wind for startup...

[Ron Hardin]

Darrel Toepfer wrote:
>
> Ron Hardin > wrote:
>
> > Of course, the exhaust blowing out the front turns the turbine backwards,
> > and the exhaust blowing out the back turns it forwards. You're where you
> > started, in explaining it.
>
> Doubtful...
>
> The starter motor spins it in a set direction. You'd have to reverse the
> polarity, if electrically driven...
>
> The only fear is that of a "hot start" which has already be explained. Or
> perhaps if you had a massive tailwind and no means of turning the plane
> into the wind for startup...

That the turbine is spinning doesn't matter to the objection. The exhaust going
to the rear spins it up, the exhaust going to the front slows it down. Net effect,
zero. How does the exhaust keep it spinning?

--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Brian Whatcott]

On Wed, 06 Jun 2007 11:35:55 GMT, Ron Hardin >
wrote:

...
>
>That the turbine is spinning doesn't matter to the objection. The exhaust going
>to the rear spins it up, the exhaust going to the front slows it down. Net effect,
>zero. How does the exhaust keep it spinning?

The compressor in front provides a wall of air as dense as 6 times
standard pressure - so the expanding hot air behind it finds it
energetically advantageous to go backwards, which reinforces the wall
of air

Brian Whatcott Altus OK

[Ron Hardin]

Brian Whatcott wrote:
>
> On Wed, 06 Jun 2007 11:35:55 GMT, Ron Hardin >
> wrote:
>
> ..
> >
> >That the turbine is spinning doesn't matter to the objection. The exhaust going
> >to the rear spins it up, the exhaust going to the front slows it down. Net effect,
> >zero. How does the exhaust keep it spinning?
>
> The compressor in front provides a wall of air as dense as 6 times
> standard pressure - so the expanding hot air behind it finds it
> energetically advantageous to go backwards, which reinforces the wall
> of air
>
> Brian Whatcott Altus OK

But that back pressure slows the turbine, just as surely as going through the blades
backwards would. Equivalently, the compressor is doing more work the more you ignite
the fuel. What keeps the turbine from slowing to a stop and then everything just
blowing out both front and back?

--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Brian Whatcott]

On Wed, 06 Jun 2007 13:19:36 GMT, Ron Hardin >
wrote:

>Brian Whatcott wrote:

>> The compressor in front provides a wall of air as dense as 6 times
>> standard pressure - so the expanding hot air behind it finds it
>> energetically advantageous to go backwards, which reinforces the wall
>> of air
>>
>> Brian Whatcott Altus OK
>
>But that back pressure slows the turbine, just as surely as going through the blades
>backwards would. Equivalently, the compressor is doing more work the more you ignite
>the fuel. What keeps the turbine from slowing to a stop and then everything just
>blowing out both front and back?

If I arrange to share the motive power between compressing input air,
and accelerating exhaust air, the compressor is a load. and
accelerating the exhaust is a load.
The compressor does not normally stop if I supply energy as fuel.
And the exhaust does not normally stop if I keep supplying fuel.

Brian Whatcott Altus OK

[Ron Hardin]

Brian Whatcott wrote:
> >But that back pressure slows the turbine, just as surely as going through the blades
> >backwards would. Equivalently, the compressor is doing more work the more you ignite
> >the fuel. What keeps the turbine from slowing to a stop and then everything just
> >blowing out both front and back?
>
> If I arrange to share the motive power between compressing input air,
> and accelerating exhaust air, the compressor is a load. and
> accelerating the exhaust is a load.
> The compressor does not normally stop if I supply energy as fuel.
> And the exhaust does not normally stop if I keep supplying fuel.

The question is, though, why the combustion products don't just blow
out both ends. _All_ the turbine blades are compressors, from the point
of view of the gasses.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

[Brian Whatcott]

On Thu, 07 Jun 2007 10:26:40 GMT, Ron Hardin >
wrote:

>Brian Whatcott wrote:
>> >But that back pressure slows the turbine, just as surely as going through the blades
>> >backwards would. Equivalently, the compressor is doing more work the more you ignite
>> >the fuel. What keeps the turbine from slowing to a stop and then everything just
>> >blowing out both front and back?
>>
>> If I arrange to share the motive power between compressing input air,
>> and accelerating exhaust air, the compressor is a load. and
>> accelerating the exhaust is a load.
>> The compressor does not normally stop if I supply energy as fuel.
>> And the exhaust does not normally stop if I keep supplying fuel.
>
>The question is, though, why the combustion products don't just blow
>out both ends. _All_ the turbine blades are compressors, from the point
>of view of the gasses.


Ah, I see Ron's issue - thinking that a compressor blade is
functionally identical to a power turbine blade. Their curvatures are
different with respect to the airflow, in fact.

But I have spent too much time on this question

Regards

Brian W

[Ron Hardin]

Brian Whatcott wrote:
>
> On Thu, 07 Jun 2007 10:26:40 GMT, Ron Hardin >
> wrote:
>
> >Brian Whatcott wrote:
> >> >But that back pressure slows the turbine, just as surely as going through the blades
> >> >backwards would. Equivalently, the compressor is doing more work the more you ignite
> >> >the fuel. What keeps the turbine from slowing to a stop and then everything just
> >> >blowing out both front and back?
> >>
> >> If I arrange to share the motive power between compressing input air,
> >> and accelerating exhaust air, the compressor is a load. and
> >> accelerating the exhaust is a load.
> >> The compressor does not normally stop if I supply energy as fuel.
> >> And the exhaust does not normally stop if I keep supplying fuel.
> >
> >The question is, though, why the combustion products don't just blow
> >out both ends. _All_ the turbine blades are compressors, from the point
> >of view of the gasses.
>
> Ah, I see Ron's issue - thinking that a compressor blade is
> functionally identical to a power turbine blade. Their curvatures are
> different with respect to the airflow, in fact.
>
> But I have spent too much time on this question

Well, you might try the idea of leverage. Together with the fact that
more gas goes out than comes in, to keep it from falling afoul of
some law preventing perpetual motion machines.

--
Ron Hardin


On the internet, nobody knows you're a jerk.