large,
The fan is 7" in diameter and runs at 32,000 RPM
The engine is duel spool and is counter rotating to minimise the torque. I will post more pics in a few weeks as I am not at my PC right now
Alleycat,
The rear nozzles flow less air unfortunatly, but this can be ajusted with the size of the nozzle I may need gyros to hlep make it stable.
BMT,
The center of gravity and the mid point between the nozzles are
on the same plane, I am sure there will be plenty of fine tuning to do in this area also.

Really Interesting Projects.

I have been thinking on a project like this for some time now, but having too small kids, and too much to do at work just doesn't make the time for it.

But hey, I have many years left ...

Love to read more about the progress of these designs.

Keep up the good work.

Cheers,
// Joakim W

Ps. An YES, If you could also manage to post the old Eric Dainty's web-pages somewhere I think many of us would be up for a nice Christmas present.
Ds.

TOO COOL ! I want one !!

Awesome project - good luck and keep us informed of your progress .

Eric Baugher

I can't even conceive a contra -rotating system, seems like an engineering marvel for a small turbine. I am guessing your using a radial flow turbine wheel-ala turbo charger type. Without giving up any trade secrets, how did you machine the tubine blade, again I presume Inconel or similar. AND, 32,000 rpm to get 40 lbs usable thrust, seems like you could use the cheapest bearings made. When are you going into production? What's your stock price going to be- I want some!

The power turbine wheel was EDM'ed out of bar stock.
The high pressure turbine wheel and power wheel are both radial and the compressor centrifugal. All of my testing was done with 3 dollar bearings on the fan and held up fine, I probably have 10 hours of run time on it and they still work great. the core runs at 100k and uses ceramic bearings. I will upgrade the fan bearings to ceramic before it is time to fly.
Orders?
Would you like to be the first on the list?

Awsome Pegasus!!!! Just awsome!

EDM'ed the turbine wheel? Can I send you an IGES file to tell me if it's feasible?

Go ahead and email it to me, hopefully I will be able to view it right away. If it is doable, the problem with EDM'ing is, EDM shops charge big $ for Wire EDM'ing electrodes, then to EDM the blades
at over 1 hour per burn and you may have 25 or 30 blades.

BIG$$$$$$$$$$

Would you like to be the first on the list?

Hey -----me first!!! Hehe

If you do succeed with this awesome project and want to sell them - give me a call. I am sure that I am not the only one interested in having one.

Now way eb2fly, I call first dibs !!

Hi Pegasus

Your Harrier project is amazing!!, and your Turbo Fan is double amazing!!.
I am looking forward to seeing some more picky's and info on the engine, as concentric shaft turbo fans is also close to heart. I don't know if you have seen the thread posted on our turbo fan, which is based on the MW54 core engine. If not and u r interested I can give ya some more info.

I read in one of your earlier posts that both your turbines were radial?. Do you meen that they are radial inflow, like turbo charger units, or axial flow types?.

Hope you had a great X-mas, and that 2003 will be a great year!. I will be keeping my eye on you harrier progress, with great interst!.

I made a turbofan years ago but it did not work right.

It was powered by the new RAM 750 but
and was designed to run at over 50,000 RPMs.

Atfer a lot of running at low power, I powered it up
and the one piece turbine / thrust fan warped and
I was out of money. Knowing what I know now
I am fairly sure I could get it to work again.

ie cast the whole thing out of inconel with expantion
slots built in...

oh well

Eddie Weeks

Hi Eddie

Interesting development work on your turbo fan, there is always some one who has done it before!! .

Interestingly enough your concept with the fan as an integeral part of the LP turbine is very good, and work by Rolls Royce an such like has be done for full size practice. I have never seen any engines in the flesh, and am assuming that the stresses are two much to make the system feasable. Creep is also a huge problem due to the high centrigual loadings and high temps.

Your engine certainly looks very smart, and the concept if achievable is simple and excellent. Keep up the good work

Guy

I will get more pics on in a few weeks but here is one I can show right now. This was before the rear ducting was mounted on.

Pegasus

When you say twin spool, does that mean you have
the Fan/power turbine behind the core turbine ?

Did you run the 32,000 rpm shaft through the
center of the core turbine or below it.

Man that is cool.

Remember to get it to fly you need 3 lbs of thrust
on each axis.

I would like use your design to build a turbofan
and install it in a plane. It would have ~30 lbs of thrust
and burn a lot less fuel !!

Eddie Weeks

Yes there is a low pressure power turbine behind the high pressure wheel. The shaft does run through the core turbine.
This turbo fan is very close to the Rolls Royce Pegasus Turbo fan only with less compressor and turbine stages in it.

Hi Pegasus

Very impressive looking fan. From what I can see there are around 30 blades slotted into an alloy hub. Have you used carbon fiber for the blades?. I take it it is a single stage fan as opposed to the rolls Royce Pegasus 3 stage LP fan?.
I would be interested to know what diameter your LP shaft is, and the general clearance you are running through the HP shaft?. This has been the head ache with our fan engine, as the core is based on the MW54, which only has a 6mm diameter compressor bore. We have enlarged that to 8mm, and taken a stress factor into account for the compressor, to allow more running clearance between the two shafts. Our fan has a 4 : 1 planetary gear reduction in the hub, due to the LP turbine running at 55000rpm, so the fan runs at 12000 rpm and is 180 mm diameter. The core engine runs at 160000 rpm, and both shafts run in the same direction. the fan rotates in the opposite direction due to the gearbox. We haven't run the engine at full power yet, but have gone to about 80% and are producing around 20 lb of thrust, full power we predict about 25, to 27 lb

What are you planning for the hot gas ducting, and nozzle's for the harrier, I should think that fabricating that little lot up will be challenging, allowing for expansion/sealing of the variable rear nozzles!!.

All very good stuff

Happy new year

Guy

Yes it is a single stage fan, a 3 stage fan like the full size Pegasus would just further complicate an already comlicated project. The fan is made from prepreg carbon fiber. I am using several different materials and diameters and shapes to find the best combination for the LP shaft and have not settled on a partricular combination yet.
I will form the rear ducting, I have several drawings for the rear rotating portion but due to heat involved I have not decided on which is the best suited for the job, I will just have to start cutting metal and see what happens.

Paully,
My second attempt at a Harrier was with a 5' GR3 a Dynamax and OS 91
It could lift the plane but needed more power to transition.
I will post a pic in a week or so of it. My first attempt at a Harrier is not even worth dicussing, but was a good lesson to put things into perspective for me.

I have been thinking about your plane for a while now and
I have a few questions.

It seems you well on your way to making a the
thrust required to lift the plane.

A while back I think you said the reaction control system
would use bleed air from the low speed fan.

If that is correct, I am sure you know that the pressure
is very low behind this fan and you will need to run at
least 2 inch pipe out to the wing tips in order to make
any kind of thrust. And when you do use the control system
its going to steel thrust from the lift fan and the plane will
drop.

The Rig requires 8 lbs of stuff just to keep it level.
I tested 40 psi bleed air system but it made very little thrust.

The work you have done is incredible, and I am not
taking away from it but a working Harrier is a big job.

Eddie Weeks
http://www.corpcomp.com/weeks1/

I am planing on using 1 3/4" pipe in the fuse, the wing will be another problem due to it being so thin, but I will figure something out. The front nozzles are putting out a few more pounds of thrust than the rear, so there is some extra thrust I can use from the front to operate the reaction control valves.

Here is my second attempt at a Harrier with a ducted fan

Here is a pic of the ducted fan version of a Peagsus

Hi Pegasus

In the wing, if you change the profile gradually, you'll be able to get the area you'll need. Also, as you get closer to the tip, you may want to reduce the area a little bit to increase the air velocity at the tip get. The other thing to remember is that the tip jets open larger on the bottom than the top.

Ed

Pleased to see all these ideas for the Harrier...... great.
This photo from Pegasus of his ducted fan version could surely be driven from a free power turbo shaft (Wren?) as used on their helicopter or turboprop engines, instead of the i.c. engine....or two ducted fans if needed??
Eddie's thoughts on the thrust/pressure needed to balance his superb rig, may be because he balances on only one jet thrust nozzle instead of the four post pedestal approach that should be much more stable and easier to control with less thrust/pressure from the control nozzles??...any thoughts?
Regards
John

Eddie's thoughts on the thrust/pressure needed to balance his superb rig, may be because he balances on only one jet thrust nozzle instead of the four post pedestal approach that should be much more stable and easier to control with less thrust/pressure from the control nozzles??...any thoughts?
Regards

I under stand what you are saying and it sounds
correct but I don't think it works that way. It
does not matter weather you lift it by the
wing tips or by one point. The problem
is once the craft starts to roll or pitch you must
have a force (reaction control system) to set
it strait again. If the reaction control is week
(5% of the TOW) then the craft will respond
sluggish and slow. I good number is %10 because
I tried 5% and it was uncontrolled able)

Hope this helps.

Eddie Weeks

I guess the ultimate solution would be to design a bypass turbo fan, with enough 'go' to supply all the nozzles, and vectoring nozzels continuously, and then close the vectoring nozzles to make a control input, as opposed to opening it, hence causing more thrust available to the other vectoring nozzles. This way I guess you wouldn't have to worry about hight loss due to thrust reduction on opening a vectoring nozzles, as Eddie discussed earlier. I'm just guessing on that principle, and it would require quite a powerful turbo fan, to overcome all duct losses. Mind you Pegasus's turbofan sounds like it is there already, with 40lb on tap.

I would just like to say that your Harrier project is mind blowing, and if you pull it off, you are the man!!!

Great stuff

Guy