The Duke Axial Engine

[Old Koreelah]

1 hour ago, Kyle Communications said:

Until they get the battery technology far better you wont see them in aircraft....not only the length of time available in the air is the issue but then its charging. If you fly out west you just cant plug it into a tree...

Mark, you of little faith...

Some of our little aeroplanes are ideal for adapting to solar/battery power, especially “out west’ where grid power is thin on the ground.

With a high wing covered in super-efficiency panels, we’d no longer be looking for a shady hangar for our planes. Fly in early morning stillness and recharge the batteries while we avoid the mid-day bumps. A couple of extra fold-out panels to cover the cockpit might speed up the process.

[onetrack]

I reckon the CIGS lightweight, flexible thin-film solar panels, are going to be the dux nuts. They're in production, and currently operating at 17.5% efficiency. But the Germans reckon they can boost that to 33% with further tweaking.

 

https://news.energysage.com/sunflare-solar-flexible-solar-panels/

 

http://miasole.com/

 

https://www.pv-magazine.com/2020/10/09/cigs-cells-could-hit-efficiencies-of-33-say-germany-scientists/

[danny_galaga]

8 hours ago, Kyle Communications said:

Until they get the battery technology far better you wont see them in aircraft....not only the length of time available in the air is the issue but then its charging. If you fly out west you just cant plug it into a tree. You need a good base powersupply to be able to plug in your charger..the more capacity you require in your battery for time of flight then it totally depends on charge time..Charge time depends on how quickly the battery can accept the charge and of course you need a powersupply supply good enough to supply that rate of charge.

 

No good flying somewhere then have to overnight or spend 2 days to get enough charge in the battery to go the next part of your trip.

 

I think it will still be a long time before we see any improvement in this

 

Dont get me wrong...I would love to see electric powered aircraft but I still think I will be pushing up daiseys before it happens

 

 

 

You are right, but I doubt anyone is going to build any new IC designs now, since the serious money is from car manufacturers...

[FlyBoy1960]

I read something about Mahepa project with hydrogen fuel cells powering an electric / battery combo.  They can cross the Atlantic for about $30 of hydrogen which is made by wind turbines in the early morning when they have lower output needed for houses, etc.   You are right though Kyle, we will be long gone before we see it in a sport aircraft

[danny_galaga]

22 hours ago, Arron25 said:

Radial Motion – manufacturing light, powerful radial engines in South Australia

CORR! I've always wanted to build a Bleriot or Bleriot-like replica. Their three cylinder radial would be just the thing ❤️

[Old Koreelah]

5 hours ago, danny_galaga said:

CORR! I've always wanted to build a Bleriot or Bleriot-like replica. Their three cylinder radial would be just the thing ❤️

Danny that engine would probably make your replica heaps safer than the original; have a look at this historic photo of the intrepid man just before his historic crossing of the Channel. 

 

To me, that is a look of sheer terror.

 

 

 

 

[Garfly]

28 minutes ago, Old Koreelah said:

To me, that is a look of sheer terror.

 

 

Speaking of such (familiar) moments, this guy just realises he's pulled the cutaway handle of his main, instead of the one to deploy it.   

 

 

 

YouTube Description:

 

"We all have good days and bad days. For this static-line progression skydive student, it was just one of "those" days — he got a little confused and pulled his cutaway handle instead of his main parachute handle. Ooops. Then, instead of going straight for his reserve, he deployed his main parachute, which didn't stick around for very long before the RSL deployed his reserve. Double ooops. *insert sarcastic tone here* If you're ever itching to pull all-the-handles, just remember it's 1) main 2) cutaway 3) reserve. And if you find yourself with a pulled cutaway handle in freefall, do yourself a favor and just go straight for your reserve. Your instructor will thank you."

 

[RSL = Reserve Static Line, a backup device for automatically deploying the reserve if the skydiver cuts away their main canopy.]

Edited March 8, 2021 by Garfly

[Wirraway]

Re Bleriot, I read years ago that it was only the fact that it rained on his flight, thus cooling the Anzani, that enabled him to complete the journey. Can't find verification of that at the moment.

 

Re the skydivers error, years ago I was jumping using a "bunnytail" to deploy the main, great system but the bunnytail is prone to being dislodged from its keepers, or if you are as clumsy as I am, I was regularly "losing" it while trying to deploy.
Sadly, many have died, "chasing the bunny tail into the ground". I.e., The deployment device is sitting just above your back, and people try for too long to grab it and deploy.
So comes my time to decide, realise I have to go for the reserve. 

Like the guy in the video, I too cutaway the main in case it deployed and fouled my reserve.
My reserve was activated by a D-ring, (think classic ripcord deployment device), but as I went to pull it from it's elasticised keeper, it fell from my hand. (Told you I was clumsy).

Below 2000 feet, ground is about 7 seconds away, and my reserve deployment device is bouncing around my chest.

Managed to control the urge to flail about, back into a frog, looked down, two hands and deployed the reserve. 
The old adage,

"Panic and you die. Stop, think, act. You know have half a chance."

 

Edited March 8, 2021 by Wirraway

[IBob]

Hey, Wirraway, did you ever meet Rod White from Queensland way?

Some time way back, I arrived at Zephyrhills between rigs, to find Rod there but recovering from some ailment, and he kindly lent me his rig.

Complete with bunny tail, which I was not used to, so I made a whole load of practise motions on the ground.

But which made no difference at all: come opening time, I could not find the damned thing.

I knew they could become detached and flap in the breeze, so after a moderate amount of groping, and with the telegraph poles starting to spread out, I pulled the reserve, and found myself under a small round dome: Rod had shortened the reserve lines so much to get it in the pack, it was like wearing a big hat. And it oscillated like crazy.

On landing, I found the bunny tail still firmly attached exactly where it was supposed to be. When I apologised for dumping his reserve, Rod said that was okay, he had wondered how it would be, short lined.............)

[Wirraway]

Great story bloke. So did you enjoy being a "test pilot"???  🙂  

I loved the bunnytail except for the fact that it started playing with my mind, I would lose the bunnytail on every second jump, seriously. Obviously managed to find it, but ended up converting to a throwaway.

 

No don't recall a Rod White. Did a bit of jumping out of Violet Town in Victoria in the late 80s. Pilot was a Buckley......was Ben Buckley the famous one? I recall this guy being his brother.  In-flight door was a big plus in the cold of a Victoprian winter
My main dropzone in W.A. was Lake Clifton, managed to get the occasional jump out of a Pilatus Porter, magic aircraft.

[IBob]

Yep, Wirraway, it never made much sense to me having your main deployment where you can't actually see it. But then I was raised on ripcords, and the training routine was: look for the handle/ now come in and pull the handle. You can see with the guy in the video, he doesn't get to look: he just grabs something, and his muscle memory has him grab the cutaway pad...

 

Yep, great jump ship the Pilatus, if a bit smelly and with a slightly queasy wallowing action when hanging on that prop in a steep climb. I never jumped one in Oz, first came across one at a Peterborough meet in the UK, where we also got to be 10 items of ballast when it was demoed to the military on a very windy day, so got to experience the vertical ride down as well as the ride up............)

[kgwilson]

For us non bombers what does a bunnytail look like? Presumably short and fluffy.

[IBob]

9 minutes ago, kgwilson said:

For us non bombers what does a bunnytail look like? Presumably short and fluffy.

It's a small pad, or other sort of grabable item, either velcroed onto the back lower corner of the pack, or tucked in under the pack flap there, but protruding. In the video, you can see it blowing around on the jumper's right at about waist height. It is attached to the apex of the soft pilot chute, so that when you drag it out the pilot chute remains collapsed until you let it go (preferably at arms length to get it out of the burble over the jumper's bac)k.

The pilot chute is attached to the umblical cord, a simple loop of which is acting as a soft pin holding the backpack shut; from there it is attached to the canopy.
So releasing the pilot chute, allowing it to inflate, both opens the backpack and drags out the canopy (which is usually in some sort of soft sub-container).

 

The development was interesting. For years after WW2 we had:

1. Ripcords with pins that threaded through metal cones on the backpacks, and bungies on the pack flaps to encourage them to open. Various things could go wrong with this, (though fortunately not too often, if understood and maintained).

2. A two-shot system requiring both hands to unlatch a mechanical assembly in two distinct steps at the shoulders in order to cut away, or jettison, the main chute. This was a military innovation, developed to prevent airborn troops being dragged on the ground in high winds, and never intended for freefall use. Used in a modified and slightly less clunky form known as a one-and-a-half-shot. It worked okay like this.

 

and 3. We then had the arrival of low-porosity fabrics and square canopies, which opened much harder than round canopies, sometimes injuring and not infrequently knocking out the jumper.

 

And in a period of 2 years, maybe less, all these problems were neatly solved:
1. Ripcords, cones, bungies and spring loaded pilot chutes gave way to simple soft throw-away pilot chutes (originally mounted on the waist band where you could see them.)

2. The modified military two-shot release was replaced by the simplest cleverest most reliable thing called a 3-ring circus, operated with a single soft handle (as seen in the video!) https://en.wikipedia.org/wiki/3-ring_release_system

3. The problem of slowing openings was finally solved with the simplest of devices: a slider, which is a reinforced fabric rectangle with a big grommet in each corner, a quarter of the lines being threaded through each grommet, and the slider pulled up to the canopy when packed. On opening, the canopy spreads the lines, but does this progressively instead of instantaneously as the slider slides down the lines.

[danny_galaga]

19 hours ago, Old Koreelah said:

Danny that engine would probably make your replica heaps safer than the original; have a look at this historic photo of the intrepid man just before his historic crossing of the Channel. 

 

To me, that is a look of sheer terror.

 

 

 

 

Hehe. Yeah it was a bit of luck that he was first. Blackburn was supposed to be the better.

[Bruce Tuncks]

Why not carry a few liters of water to spray on the engine when it needed it?

 

[Wirraway]

Goid question Bruce.

 

re the “bunnytail”, pages 9-13 discuss the various deployment systems if you want a better understanding of the differences between ripcord, bunnytail or throwaway.

 

Canopy deployment ststems. Scroll to page 9

[F10]

That Duke had one glaring problem, glossed over in the tube clip. Essentially a rotating engine block, with a still standing cylinder head....😬🙈frought with potential probs...cooling not really discussed either. You would think with computer cad drawing tech, modern electronics and materials available today, (ceramics?) someone would be able to produce a small gas generator turbine, in other words a very small let’s say 200 SHP turboprop. Surely this technology doesn’t need to be so expensive anymore? They certainly aren’t very complex. Fuel consumption I guess, will be possibly an issue.....

[F10]

Awesome! Looking at dates, any recent news on this? Imagine starting up my Gazelle, with it making a turbine whistle noise like that! 

Edited May 13, 2021 by F10

[F10]

I wonder if they could look at shortening the engine with air tubes and a rear combustion chamber, like the the Alison 250 engine used in the Jetranger helicopter. That reverse flow layout makes the engine really small. 3000 hour TBO! I think like the rotor drive of an Alouette III, I wonder if a fixed pitch prop could be used, with a freewheel unit and centrifugal clutch? So any ground idle, no drive to the prop, any over speed and the freewheel unit de-couples the engine from overspending with the prop, in a dive for example. Fuel governor keeps the prop speed constant with changing load. This would however add a lot to complexity and cost, so the VP prop cheaper in the long run? Very interesting this turbine!

[Marty_d]

Fuel consumption is eye-wateringly high in turbines compared with IC.  Plus they operate most efficiently at high altitude and high speed, two things that don't really apply to our type of flying.

There's a bloke who fitted a Garrett JFS-100-13A turbine (I think from memory it was an APU) to a CH701.   Sounds fantastic but as it says - 16 GPH for about 90 BHP at the prop shaft - that's about 60 litres per hour compared to 17ish for a 100hp 912...

 

 

[danny_galaga]

The main design flaw of any of these new engine designs is the are forty or fifty years too late. There's really no point now.

[Blueadventures]

21 hours ago, Marty_d said:

Fuel consumption is eye-wateringly high in turbines compared with IC.  Plus they operate most efficiently at high altitude and high speed, two things that don't really apply to our type of flying.

There's a bloke who fitted a Garrett JFS-100-13A turbine (I think from memory it was an APU) to a CH701.   Sounds fantastic but as it says - 16 GPH for about 90 BHP at the prop shaft - that's about 60 litres per hour compared to 17ish for a 100hp 912...

 

 

Plus they are very noisey and that is not favourable for flying quietly over close by houses, also noisy during run up on airfield and on shut down.  Every time I am at Shute harbour airstrip I feel sorry for those who are staying at the caravan park next door.  Turbines are a nice sound; but regular noise is not welcome in our under 600 kg aircraft. I’ll take cover now and await some replies. 

[spacesailor]

Just as bad as helicopter 'thump thump ' noise' , if too close it,s a pain in the ear,s.

spacesailor

[Old Koreelah]

On 14/05/2021 at 8:31 PM, Blueadventures said:

Plus they are very noisey and that is not favourable for flying quietly over close by houses...

I agree, Bluey. Decades ago the American off-road motorcycle sport, under public pressure, ran a campaign to reduce 2 stroke exhaust noise (less sound=more ground). 
Sport aircraft face similar pressures in many closer-settled areas. My jab engine is so quiet that people usually don’t notice when I fly over their place. Who could complain about electric planes?

[spacesailor]

I don,t complain  !

BUT

l hear those electric model planes Three blocks away from their flying field.

No sound from the motor, but the scream of the propeller,

& they,r tiny compared to a full size plane,s motor.

spacesailor