New Aussie Turboprop engine (200 HP) introduced at Sun 'n Fun

[Geoff_H]

I got a quote 10 years ago for refurbished blades for a 60MW GT of $6M.  Cheap blades will not take high temperatures hence low efficiencies high fuel consumption.

[onetrack]

Ceramic matrix composites appear to be the answer to the requirements for high temperature abilities in turbine engines. GE has spent US$1.5B on CMC development and the technology is steadily improving turbine performance.

 

https://www.ge.com/news/reports/hotter-air-ceramics-are-the-secret-to-lighter-faster-jet-engines

 

Sorry, KGW, I missed your mention of fuel thirstiness in your first post. I've been under the knife for eye surgery this week, and my vision hasn't been 100%, and still isn't, as I recover.

[kgwilson]

Turbines generate an enormous amount of heat that just goes out the tailpipe so a lot of the energy of the fuel ends up as wasted heat. Only some of it is converted to thrust. I'd say this is why high bypass turbo fans are so much more efficient as a straight turbo jet throws so much energy away as heat and in early designs heaps of unburnt fuel as well.

Edited April 10, 2022 by kgwilson

[facthunter]

The high bypass turbofan is only another way of getting more thrust from a pure jet engine as is a turboprop.. The larger turbofans are equivalent of 50-60,000 horsepower. You couldn't build a piston engine that big let alone want to live with it  Exhaust pipes on pistons are red hot and torch when rich Jet engines never do unless an afterburner is used and then a ridiculous amount of fuel is used.. Nev

[pmccarthy]

2 hours ago, Bruce Tuncks said:

PMC, is not copper recyclable? I reckon the same goes for lithium and lead....  battery stuff which seems not to be recycled as it should be.

Copper is very recycleable and should never be landfilled. The problem is the demand for more copper for new electrical things that more people will be wanting. Demand far exceeds supply, price will go way up and we will not get our wind, solar and battery goodies. Hence the IC engine will be around much longer than current predictions.

[pmccarthy]

1 hour ago, onetrack said:

I've been under the knife for eye surgery this week, and my vision hasn't been 100%, and still isn't, as I recover.

I thought you weren't looking too well.

[Geoff_H]

5 hours ago, facthunter said:

The high bypass turbofan is only another way of getting more thrust from a pure jet engine as is a turboprop.. The larger turbofans are equivalent of 50-60,000 horsepower. You couldn't build a piston engine that big let alone want to live with it  Exhaust pipes on pistons are red hot and torch when rich Jet engines never do unless an afterburner is used and then a ridiculous amount of fuel is used.. Nev

Actually the aircraft turbine derivatives that I have worked on were more like 93,000hp.  The largest non derivative I worked on the desighn was approx 250,000 hp.  Stationary turbines are also much more efficient using water injection and evaporative cooling of inlet air.  

[Geoff_H]

I thought about the comments about the dreaded thirst of gas turbines. I looked at the power increase required to increase the speed of a Mooney 201.  Let's look at increasing the speed by 50%, to 300mph. Drag increases by the square of the velocity, horsepower is proportional to the product of the speed and the force. Hence to power a 50% increase in speed I must increase the power of the engine by 1.5 raised to the power of 3, around 3.3 times.  The Mooney would need to increase its power from 200hp to 660hp.  Plus whatever drag would increase by owing to increasing main spar strength and up isconsequent weight.  So apart from finding a 660hp piston engine we would probably need to go to a gas turbine.  If it has the same thermal efficiency as the piston engine we are going to burn 3.3 times as much fuel.  For the same range we are going to require increased weight for the extra fuel which will incur more drag  etc etc.  The exercise looks something like a TBM 800, a Mooney designed aircraft.

Speed alone I creases required horse power by dramatic amounts, probably why turbines seem to be very thirsty.

[APenNameAndThatA]

39 minutes ago, Geoff_H said:

I thought about the comments about the dreaded thirst of gas turbines. I looked at the power increase required to increase the speed of a Mooney 201.  Let's look at increasing the speed by 50%, to 300mph. Drag increases by the square of the velocity, horsepower is proportional to the product of the speed and the force. Hence to power a 50% increase in speed I must increase the power of the engine by 1.5 raised to the power of 3, around 3.3 times.  The Mooney would need to increase its power from 200hp to 660hp.  Plus whatever drag would increase by owing to increasing main spar strength and up isconsequent weight.  So apart from finding a 660hp piston engine we would probably need to go to a gas turbine.  If it has the same thermal efficiency as the piston engine we are going to burn 3.3 times as much fuel.  For the same range we are going to require increased weight for the extra fuel which will incur more drag  etc etc.  The exercise looks something like a TBM 800, a Mooney designed aircraft.

Speed alone I creases required horse power by dramatic amounts, probably why turbines seem to be very thirsty.

I think turbines have poorer fuel efficiency even when taking power into account.   

[Geoff_H]

6 minutes ago, APenNameAndThatA said:

I think turbines have poorer fuel efficiency even when taking power into account.   

Far too general a statement.  Quality gas turbines can get to 40% efficiency with expensive Blade material and multiple compressor stages.  Higher than all but the most sophisticated piston engines.  Cheap turbines do have poor fuel efficiency.

[turboplanner]

1 hour ago, Geoff_H said:

I thought about the comments about the dreaded thirst of gas turbines. I looked at the power increase required to increase the speed of a Mooney 201.  Let's look at increasing the speed by 50%, to 300mph. Drag increases by the square of the velocity, horsepower is proportional to the product of the speed and the force. Hence to power a 50% increase in speed I must increase the power of the engine by 1.5 raised to the power of 3, around 3.3 times.  The Mooney would need to increase its power from 200hp to 660hp.  Plus whatever drag would increase by owing to increasing main spar strength and up isconsequent weight.  So apart from finding a 660hp piston engine we would probably need to go to a gas turbine.  If it has the same thermal efficiency as the piston engine we are going to burn 3.3 times as much fuel.  For the same range we are going to require increased weight for the extra fuel which will incur more drag  etc etc.  The exercise looks something like a TBM 800, a Mooney designed aircraft.

Speed alone I creases required horse power by dramatic amounts, probably why turbines seem to be very thirsty.

Good conclusion; that's where the maths takes us.

If you can produce much faster trip times carrying more load with the negatives of much higher prime cost and much higher fuel cost, your market has to be applications which want the benefits and can pay the costs.

Hence the WalMart pricing concept that led to the huge success of the current turbine based RPT industry, and the use in aircraft like the Cessna Caravan and Kodiak 100.

 

Hitching a Turbine to a Recreational aircraft requires some thought about VNE and what the annual sales volume would be to the rich and famous.

[Ian]

On 08/04/2022 at 12:39 AM, pmccarthy said:

We will not have the mineral raw materials to build electric aircraft, or cars, in the numbers required. This is a fundamental blockage, not something that can be overcome by more spending. For example, even if exploration and development of copper mines is accelerated to the maximum, we will have a deficit of one million tonnes of raw copper per year for the next twenty years. And other minerals are similar or worse.

In relation to cars, this isn't a view being borne out by industry except Toyota whose strategic direction is increasingly at odds with the market. IC cars are going the way of the dinosaur like it or not, to believe otherwise is a bit niave.

Your concerns relating to limited availability of materials don't really stack up. While copper's a prime choice for things like engine windings materials like aluminium are generally more cost effective and available, yes you lose some size and efficiency advantages. This is why the power cables near your house are aluminium and not copper. It's also why everyone doesn't use 98 octane fuel.

Lithium is a finite resource however there's actually a lot of it about and it's an industry in its infancy. You can also make Sodium Ion batteries which don't really have the same resource constraints.

 

I can't see electric planes for anything except training platforms where the pilot does 10 circuits and then lands or short hop metro flights. Trucks are also another matter however I'm expecting a bit of a resurgence in rail freight in the coming decades.

 

I wish the builder well and I'd like to see turbine engines going forwards however I think everyone struggles with fuel costs and turbine efficiency generally means higher costs unless you've been unusually clever. The other problem with turbines is that they don't throttle well so you don't get the chance to reduce that fuel burn once your at altitude.

 

That being said there are a number of markets where a cost effective turboshaft engine would be very attractive.

 

 

[Bruce Tuncks]

Geoff_h, what do you think about putting one in a Jab230?  I would like the extra power, but would not need or want to fly over 120 knots on cruise.

( 120 knots is where the ASI goes from green to yellow).

As far as weight is concerned, the figures show a substantial saving over the 3300 engine, and at least in my case, there are a few kg of lead which could be taken out the tail end.

 

[turboplanner]

5 minutes ago, Bruce Tuncks said:

Geoff_h, what do you think about putting one in a Jab230?  I would like the extra power, but would not need or want to fly over 120 knots on cruise.

( 120 knots is where the ASI goes from green to yellow).

As far as weight is concerned, the figures show a substantial saving over the 3300 engine, and at least in my case, there are a few kg of lead which could be taken out the tail end.

 

How much would you pay for it?

[Bruce Tuncks]

Bugger! at the risk of answering my own question, I see the weight of the turbine is 123kg installed compared with 81kg for my 3300 jabiru motor.

AND the fuel usage of 47.6  l/hr is more than the Jabiru uses which is 20  l/hr.

It looks so small and light, and turbine motors are mounted ahead of where ic engines go on ag planes, so I just assumed it was a lot lighter than the 3300 ic.  Of course it is more powerful, so maybe it should be compared with the Lycoming 360.

Looks like I'll be waiting for better batteries before going electric.

[turboplanner]

1 minute ago, Bruce Tuncks said:

Bugger! at the risk of answering my own question, I see the weight of the turbine is 123kg installed compared with 81kg for my 3300 jabiru motor.

AND the fuel usage of 47.6  l/hr is more than the Jabiru uses which is 20  l/hr.

It looks so small and light, and turbine motors are mounted ahead of where ic engines go on ag planes, so I just assumed it was a lot lighter than the 3300 ic.  Of course it is more powerful, so maybe it should be compared with the Lycoming 360.

Looks like I'll be waiting for better batteries before going electric.

Go back to my post on Applications which allow high Prime Cost and high fuel consumption.

Ag Plane operators get their income from rich farmers like you.

[turboplanner]

17 minutes ago, Ian said:

In relation to cars, this isn't a view being borne out by industry except Toyota whose strategic direction is increasingly at odds with the market. IC cars are going the way of the dinosaur like it or not, to believe otherwise is a bit niave.

The tribe has pretty much spoken on EV - market share has failed to fire, and apart from finding the current minerals (as against an academic assumtion that new minerals or processes will be found/invented), Prime Cost is beyond families and so is incentivising using taxpayer (our) money (50% market penetration - $15 bn/year start up. increasing exponentially by $15 bn/yr. Range limit knocks out most applications.

17 minutes ago, Ian said:

 Trucks are also another matter

Two pilot programmes where you would think there would be a chance - local delivery/local return to base applications, have been shut down.

17 minutes ago, Ian said:

however I'm expecting a bit of a resurgence in rail freight in the coming decades.

In theory, however it still can't pick up from a factory/distributor and deliver to the customer's premises; its these two transfer costs that is stopping it.

 

[Ian]

1 hour ago, Geoff_H said:

Far too general a statement.  Quality gas turbines can get to 40% efficiency with expensive Blade material and multiple compressor stages.  Higher than all but the most sophisticated piston engines.  Cheap turbines do have poor fuel efficiency.

Hi Geoff, do you have any information on the relative efficiencies of smaller low cost turbines and their ability to throttle?

Based upon this specific fuel consumption table anything small has pretty horrible fuel economy and this is at maximum efficiency not part power.

One of the reasons why jets fly at high altitudes is to achieve the best angle of attack because they can't throttle efficiently. An aircraft that can throttle efficiently can achieve maximum range regards of altitude, you simply need to slow down to achieve the best angle of attack. Flying higher reduces trip time but does nothing for efficiency. (However you might gain some by flying lower)

 

I'd actually like to see someone makes a smaller Junkers Jumo 204 even in 1940 the fuel numbers were pretty good.

19 hours ago, pmccarthy said:

Demand far exceeds supply, price will go way up and we will not get our wind, solar and battery goodies. Hence the IC engine will be around much longer than current predictions.

I don't think that supply issues will constrain the transition to away from fossil fuels for vehicles, supply is easy to fix. Issues associated with dispatchable power and distribution will have a greater impact. As soon as you have to pay for carbon capture instead of polluting those EVs start to look really good.

For instance the cost to supply Singapore with intermittent Solar from the NT was ~40B to supply 20% of their power needs some of the time using HVDC.

 

 

[Bruce Tuncks]

HAR!  Gosh it would be good to be a rich farmer...Here's the question going around...

  Q:

"how do you make a small fortune from farming?"

 

answer:

 

You start out with a large fortune.

[Geoff_H]

2 hours ago, APenNameAndThatA said:

 

Check out the dates of the original manufacture of the engines in the brake specific field consumption.  Of GT and piston increase dramatically as date gets more recent.  

GT low power very low bsfc are a function of air compressor pressures at low speed.  Hence low "compression ratio".  I always ran my Mooney at full throttle, landing very much excepted.  

[Bruce Tuncks]

I was just reading about how ev's were selling like hot cakes and how used ev's were also selling well.

Look at power tools...   the battery ones would be outselling corded ones for sure. And the increasing price of petrol sure is helping ev car sales.

Maybe our next car will be battery electric? I like the way there is bugger-all maintenance on electric stuff.

[pmccarthy]

24 minutes ago, Ian said:

 

I don't think that supply issues will constrain the transition to away from fossil fuels for vehicles, supply is easy to fix.

 

 

My point is that supply is not easy to fix, it is impossible to fix. The known deposits of major minerals are quite inadequate to deliver the supply. The time from drill discovery to first production for any major deposit is more than twenty years, even assuming community support for a project. And there are increasingly stories like this from January 2022:

 

The Serbian government has revoked the lithium mining licences granted to Rio Tinto after growing opposition to the company’s plans. Ana Brnabić, the Serbian prime minister, said all decisions and licences regarding Rio Tinto’s plans had been annulled because of environmental concerns.

[Bruce Tuncks]

Is it not probable that environmental concerns are the province of the rich and well-fed?

With the exception of global warming, I reckon there are too many politically correct bleeding hearts stopping progress.

Here's an example...  the highway to Melbourne from Ararat has been halted because "indigenous" ( but they look very white to me ) types  have demonstrated against the removal of a single tree, said tree being far too young to have been used in Aboriginal times.

 

 

 

[turboplanner]

1 hour ago, Bruce Tuncks said:

Is it not probable that environmental concerns are the province of the rich and well-fed?

With the exception of global warming, I reckon there are too many politically correct bleeding hearts stopping progress.

Here's an example...  the highway to Melbourne from Ararat has been halted because "indigenous" ( but they look very white to me ) types  have demonstrated against the removal of a single tree, said tree being far too young to have been used in Aboriginal times.

• My experience indicates the opposite; the rich and well-fed seem to be happy with out environment, the people tying themselves to dozers etc seem to be skinny menu under 30 and women with long hair around 20, neither having any money.
• Where there are legitimate environmental issues the people beating the developers tend to be quiet, keep away from the scene, and do an incredible amount of homework.
• The tree is claimed to be a birthing tree.
• A gum tree a metre or so in diameter (not circumference) can be around 150 years old, and from memory the tree was much bigger.

So far so good

 

You'll be pleased to know you're not losing your eyesight because the people which appear white to you seem to be in direct portion to the remote, genuine tribal people who urgently need help and the multi-billion dollar aborindustry which can turn a buck out of anything,  and, as you would imagine most tribes became extinct by the end of the 1800 to 1930s. You might have heard about the last Boandik "Lankey" from Beachport.

I haven't taken too much notice of the birthing tree on the Western Highway, but certainly someone should be doing some homework.

 

Global warming has been stopped by the records from Fort Dennison.

[Geoff_H]