Idea for jet engines, who to contact?

[StefanLazic]

Hello everyone.

I had an idea relating to jet engines. I think the innovation could give a slight edge to fighter aircraft by reducing the number of parts, weight and size of jet engines. I'd like to share it with the military (NATO) first, in case they find it worth of keeping secret, but I don't have any contacts. I tried to contact lockheed and boeing through the email addresses that I found on their web sites, but never got a response. Can someone help out?

Otherwise I'll just share the innovation here and everyone will be able to see it.

[Phi for All]

If you had the credentials to design a better engine, you would know exactly who to contact. Without those credentials, even if you were given the right contacts, they would be too busy reviewing designs from those with better credentials. Nothing personal, just the way things are.

I'd invite you to share the designs here. You'll get some valuable input and hopefully everyone will learn a little. If NATO contacts the Admins and has them shut down this thread, then you know you're onto something.

[koti]

North Korea are behind firewalls so you can post it here safely. 

[studiot]

26 minutes ago, Phi for All said:

If you had the credentials to design a better engine, you would know exactly who to contact. Without those credentials, even if you were given the right contacts, they would be too busy reviewing designs from those with better credentials. Nothing personal, just the way things are.

I'd invite you to share the designs here. You'll get some valuable input and hopefully everyone will learn a little. If NATO contacts the Admins and has them shut down this thread, then you know you're onto something.

 

It would be perfectly possible, perhaps even desirable at the outset, to discuss your idea in general terms before moving on to fine detail.

You particularly mention use for jet fighters.

What particular new features would your innovation bring?

Would these be compatible with the extreme requiremets of jet engine fighters?

Don't forget these meet have a much wider range of operating conditions (eg high altitude, low pressure) than ordinary jets.
This rules out many conventionally known solutions.

Do you know that jet engines are tested agains bird strike by firing forzen chickens at them with a cannon?

Would your engine withstand the impact?

[StefanLazic]

The idea is to remove the stators from the axial compressor and replace them with rows of rotors rotating in the opposite direction. It's a two-spool design where there are 2 turbines, one turbine rotating clockwise, the other counter-clockwise, powering a compressor where the alternating blade rows are counter-rotating respective to each other. One turbine transfers power to one set of compressor rotors through the inside, the other turbine transmits the power to the other set of rotors through the outside. At the core of this innovation is the linking of the compressor rotors through the outer shrouds of the blade rows (where the torque from the turbine will go to), which I believe that no one has thought of yet.

 

In the following picture you can see in green the clockwise turning turbine connected to the clockwise turning set of compressor blade rows.

In red the counter-clockwise turbine is connected to the counter-clockwise turning compressor blade rows. The power from the turbine goes through a hollow shaft to the last row of compressor blades, and then through the outer shrouds from one set of blades to another. The counter-clockwise turning blades are also reinforced by an inner shroud to prevent buckling of the blades under the extreme centripetal forces and to provide an easier seal against the other set of blade rows turning clockwise.

 

There have been suggestions of using counter-rotating turbines, and some jet engines do use counter-rotating turbines to get rid of one row of stators (stationary blades/airfoils) between the turbines. But as far as I know, no one has ever thought of using counter-rotating, stator-less axial compressors.

Clockwise and counter-clockwise are relative. I use these terms to differentiate the rotating direction. Not to define the rotating direction.

[MigL]

Can't say for certain, as its been years since I read and thought about it, but Rolls Royce may already have a patent on that idea.
( or it could be the former Bristol Siddeley aero engines, now part of RR, who holds the patent )

I know there have been RR 2 spool designs with counter-rotating spools ( RR Pegasus in the HS Harrier VTOL aircraft ), to combat gyroscopic effects which would be disastrous fo a hovering aircraft, but I think stators/guide vanes are still used in the Pegasus, which is an extensive modification of the 50/60s era Bristol Siddeley Orpheus.

In the Western world, the big three military engine manufacturers are the already mentioned British Rolls Royce, General Electric and the Pratt and Whitney division of United Technologies, both American.
Smaller players are Safran ( formerly SNECMA ) of France, MTU of Germany, FIAT avio of Italy, Volvo-Flygmotor of Sweden, and the American Allison ( owned by Rolls Royce ).

Boeing and Lockheed-Martin don't manufacture aero engines, turbine or otherwise.

Edited June 9, 2018 by MigL

[StefanLazic]

4 hours ago, MigL said:

Can't say for certain, as its been years since I read and thought about it, but Rolls Royce may already have a patent on that idea.
( or it could be the former Bristol Siddeley aero engines, now part of RR, who holds the patent )

I know there have been RR 2 spool designs with counter-rotating spools ( RR Pegasus in the HS Harrier VTOL aircraft ), to combat gyroscopic effects which would be disastrous fo a hovering aircraft, but I think stators

They have counter rotating spools, but one spool turns one compressor and the other spool turns another separate compressor. It's explained on wikipedia: https://en.wikipedia.org/wiki/Rolls-Royce_Pegasus#Design

My idea is to take the two separate compressors and join them together in a single unit, in order to eliminate the stator blades and reduce the amount of parts, weight and size of the engine.

I did some CFD simulations using CFX on the counter-rotating compressor and it looks like the  counter-rotating stator-less compressor performs just as well as one with stators. Unfortunately I have only 16 GB of RAM and I could not use fine meshes nor many compression stages, so I can't tell for sure.

Edited June 9, 2018 by StefanLazic

[Bender]

How do you get less parts and weight by replacing the stator blades by more complex and more fragile rotating blades?

[StefanLazic]

2 hours ago, Bender said:

How do you get less parts and weight by replacing the stator blades by more complex and more fragile rotating blades?

One rotating row and one stator row forms a stage. A traditional design with 10 stages would need 20 rows (10 rotating, 10 stationary).

A counter-rotating design with 10 stages would need just 10 rows (no stationary blades). That's a 50% reduction.

Check out wikipedia for a better understand on how axial compressors work: https://en.wikipedia.org/wiki/Axial_compressor

Edited June 9, 2018 by StefanLazic

[koti]

12 minutes ago, StefanLazic said:

One rotating row and one stator row forms a stage. A traditional design with 10 stages would need 20 rows (10 rotating, 10 stationary).

A counter-rotating design with 10 stages would need just 10 rows (no stationary blades). That's a 50% reduction.

Check out wikipedia for a better understand on how axial compressors work: https://en.wikipedia.org/wiki/Axial_compressor

I think you need to concentrate on bulding a prototype and after a series of tests it will turn out if it will be more efficient. I assure you, you will come across issues which you have not accounted for when working with a prototype.

[StefanLazic]

11 minutes ago, koti said:

I think you need to concentrate on bulding a prototype and after a series of tests it will turn out if it will be more efficient. I assure you, you will come across issues which you have not accounted for when working with a prototype.

Building a prototype is expensive. Maybe I should start a crowdfunding campaign

[Frank]

This may be of interest:

COMPARISON OF COUNTER–ROTATING AND TRADITIONAL AXIAL AIRCRAFT LOW-PRESSURE TURBINES INTEGAL AND DETAILED PERFORMANCES  http://softinway.com/wp-content/uploads/2013/10/Comparison-of-Counter-rotating-and-Traditional-Axial-Aircraft-Low-pressure-Turbines-Integral-and-Detailed-Performances.pdf

[koti]

9 hours ago, StefanLazic said:

Building a prototype is expensive. Maybe I should start a crowdfunding campaign

I don’t share your humour. If you think its worth pursuing you should go at it.

[StefanLazic]

6 hours ago, koti said:

I don’t share your humour. If you think its worth pursuing you should go at it.

Lets say that I build two prototypes (one with a traditional design and one with a counter-rotating design) and find that the counter-rotating design is better, what then? Where do I publish the results? Care to give some contacts? Otherwise I just spent a lot of money for nothing.

[Bender]

18 hours ago, StefanLazic said:

One rotating row and one stator row forms a stage. A traditional design with 10 stages would need 20 rows (10 rotating, 10 stationary).

A counter-rotating design with 10 stages would need just 10 rows (no stationary blades). That's a 50% reduction.

Check out wikipedia for a better understand on how axial compressors work: https://en.wikipedia.org/wiki/Axial_compressor

Is a step in a counter-rotating design equally efficient? I would guess not, since the effect of the reversing vanes decreases when they rotate. 

1 hour ago, StefanLazic said:

Lets say that I build two prototypes (one with a traditional design and one with a counter-rotating design) and find that the counter-rotating design is better, what then? Where do I publish the results? Care to give some contacts? Otherwise I just spent a lot of money for nothing.

I wouldn't worry about that. There is quite a difference between some anonymous nobody who claims to have a new idea, and someone who has experimental results to show. If you perform the experiments properly, publishing should not be a problem.

Perhaps you can do a relatively cheap proof of concept with 3D printed scale models and pressurised air?

[MigL]

One problem that I can see...

Guide vanes and stators are used to 'straighten' the gas flow, otherwise it spirals around the engine and has an unfavorable attitude to the fan blades ( plus unwanted gyroscopic effects ). In your design, the two shafts need to spin at exactly the same speed, so that each succeeding stage can straighten the flow of the preceeding stage. Even a small difference in rtational speed will cause the gas flow to spira axially.
The shaft driven by the first turbine will necessarily spin faster than the second turbine, as gas speed has been reduced by interaction with the first.
In normal engines this isn't a problem, as the first turbine drives the outer shaft/hi-pressure compressor, while the second turbine drives the inner shaft/lo-pressure compressor at a lower speed.

That brings us to the second problem...
Most advanced engines nowdays are turbofans which have a slower turning lo-pressure compressor, and 'bypass ' air is ducted around the hi-pressure compressor. Military engines have a bypass ratio of 0.3:1 up to 1:1 depending on application, and then dump this bypass air into an afterburner/re-heat section; meanwhile commercial aviation engines can have bypass ratios of 8:1 or more, and the most advanced ones have 'geared' fans to reduce/optimize rotational speed even more.
Your design does not lend itself to these types of application.

And while a small turbojet might have applications in non-reusable missiles, most APUs and turboshaft engines use centrifugal compressors to reduce size and part count.

Have you tried contacting any of the companies I mentioned in my last post ?

Edited June 11, 2018 by MigL

[StefanLazic]

On 11/6/2018 at 4:20 AM, MigL said:

Guide vanes and stators are used to 'straighten' the gas flow, otherwise it spirals around the engine and has an unfavorable attitude to the fan blades ( plus unwanted gyroscopic effects ).

The mass of air is very small. The gyroscopic effects are negligible.

As for gyroscopic effects due to the rotation of the engine components, they will be smaller in a counter-rotating design.

 

On 11/6/2018 at 4:20 AM, MigL said:

In your design, the two shafts need to spin at exactly the same speed, so that each succeeding stage can straighten the flow of the preceeding stage. Even a small difference in rtational speed will cause the gas flow to spira axially.

What determines the direction of the airflow is not only rotational speed, but airfoil profile and angle of attack. You are assuming that the profile and angle of attack will be the same for each stage, which doesn't need to be the case. So the two shafts do not need to spin at the same speed for the flow to go straight on average.

On 11/6/2018 at 4:20 AM, MigL said:

meanwhile commercial aviation engines can have bypass ratios of 8:1 or more, and the most advanced ones have 'geared' fans to reduce/optimize rotational speed even more.

Your design does not lend itself to these types of application.

In a counter-rotating design you could have each stage rotating at a slower speed than a traditional setup while still delivering the same performance, thus optimizing the rotational speed for the slow-turning fan.

[MigL]

Agreed on the gyroscopic effects ( only valid for a hovering aircraft ), but the attitude of the gas flow entering the next stage has to be straight, otherwise the compressor blades lose effectiveness. Most older, straight turbojets use variable pitch guide vanes/stators on the first few compressor stages ( see GE J-85 and J-79 ).

Low pressure fans on turbofan engines are driven by a separate shaft/spool such that most engines are two shaft/spool designs. Only RR has ever gone to three shaft/spool designs, and they've mostly given up on more than two. Last engines to use tree shafts/spools were the 70s vintage RB 199 ( multinational ) and RB 211 ( commercial ). Complexity ( and part count ) also grow with number of bearings since at least two are needed for each shaft.

Specific fuel consumption and thrust are more important than part count these days. The most advanced military engines employ variable cycle/ bypass to optimize thrust/SFC at all speeds to supersonic, while the most advanced civil engines use geared fans to optimize the same at typical ( subsonic ) cruise.

[StefanLazic]

17 hours ago, MigL said:

the attitude of the gas flow entering the next stage has to be straight, otherwise the compressor blades lose effectiveness.

What matters is that the blades encounter the air at the right angle of attack. The flow doesn't need to be axially straight for that.

[MigL]

And how would you ensure that, since the rotation of the gas flow through the compressor changes with different compressor speed and output power ?
You can't have variable pitch fan blades, so your only option is to ensure straight flow at all times.

[StefanLazic]

14 hours ago, MigL said:

And how would you ensure that, since the rotation of the gas flow through the compressor changes with different compressor speed and output power ?
You can't have variable pitch fan blades, so your only option is to ensure straight flow at all times.

By having one row of variable guide vanes at the inlet of the compressor and by bleeding the air from the compressor after the clockwise or counter-clockwise rows, depending on need. You can use bleed air to extract power from the compressor and use it elsewhere. Like turbine cooling and air conditioning in the aircraft.

[StefanLazic]

So does anyone have any contact information?

[Frank]

The power take-off would have to draw power from both turbines somehow.

I'd like to see Pratt and Whitney develop this.  I can think of a few applications where a 30% weight reduction would be extremely beneficial.

The software used in the link I posted seems to be around $6,500 US, it could show the full cycle including the counter-rotating turbine side, not just the counter-rotating compressor.  The AC engine companies probably have similar or even better software for simulations.  Maybe try and get an internship position in exchange for some R&D time?

 

[StefanLazic]

6 hours ago, Frank said:

The power take-off would have to draw power from both turbines somehow.

I'd like to see Pratt and Whitney develop this.  I can think of a few applications where a 30% weight reduction would be extremely beneficial.

The software used in the link I posted seems to be around $6,500 US, it could show the full cycle including the counter-rotating turbine side, not just the counter-rotating compressor.  The AC engine companies probably have similar or even better software for simulations.  Maybe try and get an internship position in exchange for some R&D time?

 

Unfortunately I'm just an automation engineer and I don't have any contacts within aerospace companies, which don't exist where I live (well except RUAG, but I don't like them as they think that I'm too stupid to work for them; I can't even imagine what kind of arrogant geniuses they have in there, minimum 130 IQ each employee, all with 100 years of experience and aged under 30, and willing to work free overtime).

I'm a swiss citizen and there are no jet engine manufacturers in switzerland. Unfortunately I work full time and I don't have much free time to do R&D or to build a jet engine.

Edited June 19, 2018 by StefanLazic

[Frank]

37 minutes ago, StefanLazic said:

Unfortunately I'm just an automation engineer and I don't have any contacts within aerospace companies, which don't exist where I live (well except RUAG, but I don't like them as they think that I'm too stupid to work for them; I can't even imagine what kind of arrogant geniuses they have in there, minimum 130 IQ each employee, all with 100 years of experience and aged under 30, and willing to work free overtime).

Not hiring people like you might be why I've never hear of them... 

38 minutes ago, StefanLazic said:

I'm a swiss citizen and there are no jet engine manufacturers in switzerland. Unfortunately I work full time and I don't have much free time to do R&D or to build a jet engine.

Being an inventor isn't easy, torn between inventing and making a "standard" living.  If you're lucky enough to make your first venture pay off, then it can fund the next ones, but that first one, like any invention, has a low chance of commercial success.  On the other hand, Switzerland is a great place to live so you can keep working at it.  I'm not in a position to advise you, but I'm trying networking to find partners and pursuing relatively cheap ideas to kickstart this process, then maybe someday fund the big/expensive ones.

I suppose also, that distance isn't as much of a factor given the internet, and 3d-printing makes manufacturing capability (maybe not for a jet engine) less expensive.  Exciting times.