Van's Air Force
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Deltahawkengines
- Thread starter mlw450802
- Start date
They told me during a phone conversation with them.
Not quite true - any purchase contract constitutes a guarantee of payment for engines delivered.
Yep. Can't say that I have any real inside information that explains why businesses make the decisions they do - but I have seen several profitable businesses go down the tubes over the years because the current management made decisions that I and other "worker bees" knew were OBVIOUSLY stupid. So goes the world.
I don't take a position on whether or not DeltaHawk will be successful, but I do have to agree that it would make sense for them to have as many engines flying as possible if their intent is to make it big. Even accidents can provide evidence that the basic design is or is not good.
Not that I'm aware of and I'm sorry to say that Deltahawk is starting to look a lot like Zoche. Get the financing in place and just do it. Test it lots in your own aircraft, fix the glitches and get it into the experimental market. Once you make your R&D costs back, then think of certifying it if you must.
They are incrementally working towards release of engines for sale and certification and you must give them credit for staying with this so long. I don't buy their updated comparison of specs and costs vs. an IO-360. Pretty sure an IO does not burn 10 gal./hr. at 65% nor are people replacing spark plugs every 200 hours. Their SFC claims vary between .35 and .38 depending on the info you look at- only slightly better than a modern Lyco with FI and EI. DH should come clean on this stuff.
The longer this drags out, the more the program costs, the more the engines cost in the end and the less credibility you have.
Anyway, keep at it DH, we'd love to see how it all pans out.
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Top_prop
Well Known Member
UAV's desperate for new engines
From various sources I've heard the guys on the ground are loving the UAV's support... and thier feed back has the ear of the upper ends of the DoD.
But the .mil has a plan to go all diesel/jet fuel by 2010 (no more mo gas!). I have a friend who manufactures micro turbines for mini cruise missles... they want him to engineer a turbor prop varient for use on UAV's, but are jerking him around with funding... he's had personal visits from high ranking officers to find the money and get it done. He's holding out for them to pay for the developement.
So there is a market and lots of small companies working to get the UAV business and an expressed desire from the .mil for the product.
How this affects Delta Hawk is probably speculation at best.
my .02
Tom
From various sources I've heard the guys on the ground are loving the UAV's support... and thier feed back has the ear of the upper ends of the DoD.
But the .mil has a plan to go all diesel/jet fuel by 2010 (no more mo gas!). I have a friend who manufactures micro turbines for mini cruise missles... they want him to engineer a turbor prop varient for use on UAV's, but are jerking him around with funding... he's had personal visits from high ranking officers to find the money and get it done. He's holding out for them to pay for the developement.
So there is a market and lots of small companies working to get the UAV business and an expressed desire from the .mil for the product.
How this affects Delta Hawk is probably speculation at best.
my .02
Tom
Captain Avgas
Well Known Member
Deltahawk had their display engine at the Avalon Airshow in Melbourne, Australia in early 2005 (largest airshow in the southern hemisphere). A rep on their stand looked me straight in the eye and said they had over 200 firm orders and that the first run of engines was in production with first deliveries expected by mid 2005.
Now, almost 4 years later and not a single engine delivered. It does indeed sound a LOT like Zoche.
0.35 for SFC for a two stroke diesel with mechanical injection is hard to beleive; The Thielert FADEC 4 stroke was about at that figure;
Further, the 2 strokes generally have the optimum SFC over a very narrow RPM/Power range; 4 strokes are pretty much constant over all of the RPM/power range.
As well I whish them success, but indeed it is taking somewhat long; I hope they have not hit a technical road block !
FG
Why would a four-stroke be better with all that extra friction, higher cylinder pressures/thermal losses and what's FADEC got to do with it?
Again, I don't see much basis of fact from these comments either.
IMO, the only thing a two-stroke has going against it is the higher scavenging ratios required than a four-stroke - the rest is only advantageous.
A
Don?t read me wrong, 2 and 4 strokes diesels each have their pros and cons; There is a niche for both of them otherwise they would not exist. For 2 strokes strength it is their mechanical simplicity but they tend to lack in their ability to maintain optimality over a wider range of operation.
Looking at what is available today, my comments are based from a statistical standpoint comparing various engines SFC Charts. They factor everything and truly represent the ?what it costs vs what you get? ratio; Theory is good and correct but never accounts for the complete ?equation?.
My understanding is that a much higher air mass flow per BHP (higher pumping loads) is required by the 2 stroke diesels and, the combustion/injection processes can not be controlled to the same extent as it can be in a 4 stroke diesel (indeed pollutants control and completeness of combustion are huge challenges with 2 stroke diesels).
The 2 stroke diesels needs a lot of optimization (especially the intake and exhaust ports design) and are really optimum for one operating condition; 4 stroke diesels due to their valve arrangement offer a wider range of optimum operation.
Mechanical injection is great for aviation in terms of simplicity and reliability (SMA messed up the overall reliability of the injection system by installing an electronic ?throttle? control, nothing wrt metering/advance); However, common rail/FADEC allows you to do up to 5 injection events per cycle and real time controllable advance giving you more flexibility wrt the charge quality, output power, RPM, starting and altitude re-start capabilities, more complete burn, etc.
Looking at what is available today, my comments are based from a statistical standpoint comparing various engines SFC Charts. They factor everything and truly represent the ?what it costs vs what you get? ratio; Theory is good and correct but never accounts for the complete ?equation?.
My understanding is that a much higher air mass flow per BHP (higher pumping loads) is required by the 2 stroke diesels and, the combustion/injection processes can not be controlled to the same extent as it can be in a 4 stroke diesel (indeed pollutants control and completeness of combustion are huge challenges with 2 stroke diesels).
The 2 stroke diesels needs a lot of optimization (especially the intake and exhaust ports design) and are really optimum for one operating condition; 4 stroke diesels due to their valve arrangement offer a wider range of optimum operation.
Mechanical injection is great for aviation in terms of simplicity and reliability (SMA messed up the overall reliability of the injection system by installing an electronic ?throttle? control, nothing wrt metering/advance); However, common rail/FADEC allows you to do up to 5 injection events per cycle and real time controllable advance giving you more flexibility wrt the charge quality, output power, RPM, starting and altitude re-start capabilities, more complete burn, etc.
2 strokes have advantages but SFCs at high load/ high rpm on direct drive models isn't that great.
The Diesel Air site shows SFC as good as .38 at 2000 rpm and 65-80% power falling to .48 at max rated power and 2600 rpm. Pretty much the same as a Lycoming running LOP with EI and FI so I don't see much fuel savings with any 2 stroke designs for aviation currently.
I think lightweight aero 2 strokes have a lot to prove on the longevity front as well and will believe the 2000 hour TBOs when I see them.
What is the real advantage to these engines? Only the fact that they burn Jet fuel it seems (assuming you have this fuel where you fly). They will be expensive, relatively unproven and offer minimal gains in fuel economy over existing gasoline aero engines.
The Diesel Air site shows SFC as good as .38 at 2000 rpm and 65-80% power falling to .48 at max rated power and 2600 rpm. Pretty much the same as a Lycoming running LOP with EI and FI so I don't see much fuel savings with any 2 stroke designs for aviation currently.
I think lightweight aero 2 strokes have a lot to prove on the longevity front as well and will believe the 2000 hour TBOs when I see them.
What is the real advantage to these engines? Only the fact that they burn Jet fuel it seems (assuming you have this fuel where you fly). They will be expensive, relatively unproven and offer minimal gains in fuel economy over existing gasoline aero engines.
They will require installations that are well designed around the narrow range of optimum SFC, therefore limiting their missionability.
At ISO SFC, fuel flow wise their advantage would reside in the fact that the density of the Heavy Fuels is about 7/6 the one of 100LL; Indeed since we pay fuel to the volume, a little gain could be on cost per pound of fuel and that you can put more pounds in the same fuel tank volume.
There is a niche for all engines...however some may be smaller than others.
At ISO SFC, fuel flow wise their advantage would reside in the fact that the density of the Heavy Fuels is about 7/6 the one of 100LL; Indeed since we pay fuel to the volume, a little gain could be on cost per pound of fuel and that you can put more pounds in the same fuel tank volume.
There is a niche for all engines...however some may be smaller than others.
Ross, according to the Superior IO360 installation manual, their Lyclone will only do 0.61 lb/hp.h at full rated power which is a positive guzzler compared to the DieselAir's 0.48 (your quote)
Sure, the Lyclone can be made to produce reasonable numbers but only at a limited range of power levels and is very altitude dependent and relies on good management. A diesel is a fool-proof fuel miser.
I still don't buy the limited operating point of the two-stroke. Take the WAM-120 as an example. It operates an economy cruise BSFC of 0.43 at 2300 to a rated T/O power BSFC of 0.49 at 2700. That's neither an enormous spread of BSFC, nor a narrow operating window - in fact it's just what you want for direct drive. The numbers don't look that spectacular (it's IDI and uniflow scavenged - i.e. valvegear!) but in the real world they translate into pretty impressive fuel burn rates. A DI version would be another leap forward again.
Sure, the Lyclone can be made to produce reasonable numbers but only at a limited range of power levels and is very altitude dependent and relies on good management. A diesel is a fool-proof fuel miser.
I still don't buy the limited operating point of the two-stroke. Take the WAM-120 as an example. It operates an economy cruise BSFC of 0.43 at 2300 to a rated T/O power BSFC of 0.49 at 2700. That's neither an enormous spread of BSFC, nor a narrow operating window - in fact it's just what you want for direct drive. The numbers don't look that spectacular (it's IDI and uniflow scavenged - i.e. valvegear!) but in the real world they translate into pretty impressive fuel burn rates. A DI version would be another leap forward again.
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I have access to some non-commercial data for TAE (FADEC-common rail, 18:1, geared, liquid cooled) and SMA (good old reliable mechanical injection, shy of 15:1, direct, air-oil cooled) and their ratio of max SFC over min SFC is around 5%, that is roughly T-O Power vs Cruise Power;
Looking at the data published (web site) by some aero 2 stroke diesels (all liquid cooled with TAE like compression ratios) you have for the same T-O/Cruise SFC ratio:
- WAM-120: 14%
- DeltaHawk: 19% and 46% depending on RPM
- Diesel Air: 18% and 21% depending on RPM
Based on the above, within the operational power range of interest we can say that the SFC bucket is shallower (therefore SFC is closer to a constant) for the 4 stroke diesels when compared to the deeper SFC bucket of the 2 stroke diesels (not saying they are bad, just different).
The good thing with any Diesel engine is that they are single lever by virtue of their mechanical design (not the same for their AVGAS counterpart) : Indeed, Power lever is power lever, mixture control not required since the mixture is always lean even at T-O (even if it smokes), prop control can be like on the SMA pre-set at a fixed governed speed and it works just fine (based on 1000 hours of service experience).
Well, we spend most of our time in cruise and the 2 stroke Diesels don't show an useful advantage over a good IO Lycoming there. If we look at what Klaus Savier is doing with a Conti O-200, I'm not impressed by any flying aero Diesel yet.
A good 4 stroke Diesel might be the ticket- if anyone ever develops one and keeps the weight down and cost. The turbo at least gives some more TAS up high.
A good 4 stroke Diesel might be the ticket- if anyone ever develops one and keeps the weight down and cost. The turbo at least gives some more TAS up high.
Researching through my notes I remembered the OPOC (Opposed Piston Opposed Cylinder) that was developped a few years ago but from what I know never obviously reached mass production.
It is a 2 stroke diesel w/FADEC, common rail, Electrically Assisted Turbocharger (EAT); It achieves an SFC of 0.34 with a very shallow and wide SFC bucket and offers power densities of about 1 HP/lb and 2 HP/cubic inch @ 3800 RPM and Sea Level.
A lot of technology and reasearch were (and properly still do) required to achieve the above number. However, if it could be successfully commercialized the above number would appeal to GA.
FG
It is a 2 stroke diesel w/FADEC, common rail, Electrically Assisted Turbocharger (EAT); It achieves an SFC of 0.34 with a very shallow and wide SFC bucket and offers power densities of about 1 HP/lb and 2 HP/cubic inch @ 3800 RPM and Sea Level.
A lot of technology and reasearch were (and properly still do) required to achieve the above number. However, if it could be successfully commercialized the above number would appeal to GA.
FG
Unless there are other constraints, I would select and design my PowerPlant installation for the CRZ point and to be somewhere at the bottom of the SFC bucket.
If you assume two exactly identical a/c except for the PowerPlant installation (same cooling/cowling drag) and having the same useful load, I would initially use the following to compare the two PowerPlants:
HFCD = (SFC2 * ((Wpp2 ? Wpp1)*(Cd/Cl)*(KTAS/326)*(1/np)) + BHP1*(SFC2-SFC1))*FP/7
- The first portion calculates the additional fuel flow required to haul the extra weight of the heavier PowerPlant,
- The second portion calculates the fuel flow for the lighter baseline PowerPlant
Where,
HFCD: Hourly Fuel Cost Differential, [$/hr], (PowerPlant 2 vs 1)
SFC1: Specific Fuel consumption of lighter PowerPlant, [lb/HP/hr]
SFC2: Specific Fuel consumption of heavier PowerPlant, [lb/HP/hr]
Wpp1: Weight of lighter PowerPlant, [lb]
Wpp2: Weight of heavier PowerPlant, [lb]
(Cd/Cl): (assumed constant for the two a/c)
KTAS: True AirSpeed, [knots]
np: Propeller efficiency (assumed constant), [dimensionless]
BHP1: Brake HP for the lighter PowerPlant, [HP]
FP: Fuel Price, [$/USG]
Ex.:
SFC1 = 0.35 (typical 2 liter 152 BHP 4 stroke Diesel)
SFC2 = 0.40 (typical 3.3 liter 160 BHP 2 stroke Diesel)
Wpp1 = 295 [lb]
Wpp2 = 327 [lb]
(Cd/Cl) = 0.08
KTAS = 120 [Kt]
np = 0.8
BHP1 = 120 [HP] (approx 75%-80%)
FP = 5.00 [$/USG]
Putting these numbers in the above equation yields an HFCD of 4.62 [$/hr] in favor of the 4 stroke Diesel (9245 $ over 2000 hours of operation).
Depending on other design/operational/maintenance criteria/actual data/mission profile, the advantage could possibly be reversed, but I would bet the 4 strokes will be lucky more often. Every situation will drive its own choices.
This further confirms that there is room for all under the sun !
Rotary10-RV
Well Known Member
Exception rather than the rule
Ross, Klaus Savier has a very slick airplane with many aero mods. If he put a diesel in it the diesel would get better milage too! Very few aircraft are going to do better, but it is the airframe and mods rather than the engine that does it. If anyone can get their coventional tractor to do as well as Klaus I would like to see the plane. Two-cycle is common in diesel use and doesn't lose all its advantage since the engine is direct injected. Deltahawk has shown some excellent numbers in testing and on the Velocity in the air. I just hope they can clear the hurdle of getting production into full swing.
Bill Jepson
Ross, Klaus Savier has a very slick airplane with many aero mods. If he put a diesel in it the diesel would get better milage too! Very few aircraft are going to do better, but it is the airframe and mods rather than the engine that does it. If anyone can get their coventional tractor to do as well as Klaus I would like to see the plane. Two-cycle is common in diesel use and doesn't lose all its advantage since the engine is direct injected. Deltahawk has shown some excellent numbers in testing and on the Velocity in the air. I just hope they can clear the hurdle of getting production into full swing.
Bill Jepson
I talked to Klaus at Reno last week and not only is the plane slick, the engine may be the most efficient gasoline engine flying today with the internal and EFI/ EI mods he has done. He is WAY more efficient than any other EZE flying and I'd make a bold guess that SFC is somewhat below .36.
A lightweight Diesel would be hard pressed to match his numbers IMO.
A lightweight Diesel would be hard pressed to match his numbers IMO.
Rotary10-RV
Well Known Member
I disagree but that is life!
Ross,
I visited Klaus' hangar in Santa Paula and got a real good look while a friend had Lightspeed questions. I think you could find at least 10 engines that would do better efficiency wise than Klaus O-200, but not his airframe. I believe that the DAIR opposed piston 2 cycle diesel would KILL the O-200's BSFC. I believe several subies would best it with a purpose-built PSRU. (Light weight) I believe it is a good running O-200 making better power than most O-200's but I don't think that matters even 1/2 as much as his aerodynamic refinements. DRAG is the biggest factor in efficiency, followed by weight. Klaus' plane is LIGHT too. He has been refining it for years. Like Dave Anders (?) who broke the CAFE record in a RV-4, continual refinement was/is the key. Bringing down the drag can work wonders even with a so-so engine. Witness Mike Arnolds AR-5, 213.85 MPH on only a standard rotax 65 HP engine! I have seen Mike's F1 (AR-6) Reno plane too also very fast winning F1 this year if the results I saw were correct. I like what Klaus is doing even with the O-200 but I believe it is beatable with other engines in his own airframe. Of course your milage may vary.
Bill Jepson
Ross,
I visited Klaus' hangar in Santa Paula and got a real good look while a friend had Lightspeed questions. I think you could find at least 10 engines that would do better efficiency wise than Klaus O-200, but not his airframe. I believe that the DAIR opposed piston 2 cycle diesel would KILL the O-200's BSFC. I believe several subies would best it with a purpose-built PSRU. (Light weight) I believe it is a good running O-200 making better power than most O-200's but I don't think that matters even 1/2 as much as his aerodynamic refinements. DRAG is the biggest factor in efficiency, followed by weight. Klaus' plane is LIGHT too. He has been refining it for years. Like Dave Anders (?) who broke the CAFE record in a RV-4, continual refinement was/is the key. Bringing down the drag can work wonders even with a so-so engine. Witness Mike Arnolds AR-5, 213.85 MPH on only a standard rotax 65 HP engine! I have seen Mike's F1 (AR-6) Reno plane too also very fast winning F1 this year if the results I saw were correct. I like what Klaus is doing even with the O-200 but I believe it is beatable with other engines in his own airframe. Of course your milage may vary.
Bill Jepson
An SFC of 0.36, I would like to see solid numbers and under what conditions not just a guess; Clearly not at TO power; If the engine is a GDI, maybe but still needs to be solidly substantiated and under what very limited conditions. If the engine has a PSRU, then for it to achieve 0.36 it needs to go down to something like 0.30 to 0.33 if we want the 0.36 at the prop flange, not the engine flange if we want to compare apples with apples.
Currently aero diesel engines with 2000-3000 hour TBO are possible (hard and recent real life data supporting that does exist) at 1.6 [lb/HP], power densities of 1.25 to 1.75 [HP/cu in] and an SFC of 0.30-0.32 (from idle to TO power);
N941WR
Legacy Member
JETA4GA,
You can read about the flight on the LightSpeed web site.
Here's the link:
http://www.lightspeedengineering.com/News/News.htm
Here's the Reader's Digest version:
You can read about the flight on the LightSpeed web site.
Here's the link:
http://www.lightspeedengineering.com/News/News.htm
Here's the Reader's Digest version:
LightSpeed said:
Typically best SFC numbers are not at TO power on aircraft engines. The TC Wrights and Conti 550s running LOP are around .375 in cruise. Lycoming may be in these ranges soon with the introduction of their new IE2 engines/ FADEC system.
No way the current crop of Subaru engines would be anywhere close to what Klaus is getting with his O-200. Figures from Fuji put their best engines at no better than .42 in a very narrow rpm range, well below anything useful for aviation applications. Some of the new DI gasoline engines from Toyota, GM and BMW have just broken the .40 range.
Sorry to say there are NO aero Diesels being flown today which have accumulated enough real world flight time to demonstrate real 2000-3000 hour TBOs.
IMO it will be some time before any aero Diesel with comparable power to weight ratios to current Lycoming type gasoline engines, demonstrates these sort of TBOs in real life. Heavy ground based Diesels, yes, lightweight aero Diesels no.
Certainly the Thielert was an economic disaster with engines costing twice to 3 times that of a traditional aero engine, gearbox inspections every few hundred hours and most falling woefully short of their TBRs with a wide range of serious problems.
People are naive to think that aero Diesels will automatically duplicate the reliability of heavy ground based designs. The high continuous power settings required for aviation prime movers and the requisite high boost pressures that Diesels must run to achieve these put their longevity in question, especially in the exhaust valve and piston/ring departments. Most ground Diesels actually operate most of their lives at relatively low specific outputs.
I think the time will come but it is not here yet.
No way the current crop of Subaru engines would be anywhere close to what Klaus is getting with his O-200. Figures from Fuji put their best engines at no better than .42 in a very narrow rpm range, well below anything useful for aviation applications. Some of the new DI gasoline engines from Toyota, GM and BMW have just broken the .40 range.
Sorry to say there are NO aero Diesels being flown today which have accumulated enough real world flight time to demonstrate real 2000-3000 hour TBOs.
IMO it will be some time before any aero Diesel with comparable power to weight ratios to current Lycoming type gasoline engines, demonstrates these sort of TBOs in real life. Heavy ground based Diesels, yes, lightweight aero Diesels no.
Certainly the Thielert was an economic disaster with engines costing twice to 3 times that of a traditional aero engine, gearbox inspections every few hundred hours and most falling woefully short of their TBRs with a wide range of serious problems.
People are naive to think that aero Diesels will automatically duplicate the reliability of heavy ground based designs. The high continuous power settings required for aviation prime movers and the requisite high boost pressures that Diesels must run to achieve these put their longevity in question, especially in the exhaust valve and piston/ring departments. Most ground Diesels actually operate most of their lives at relatively low specific outputs.
I think the time will come but it is not here yet.
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This is an interesting article; However, it would have been nice if we could have had some dyno data where conditions can be better controlled and, the actual BHP at the prop flange and fuel flow can be obtained with high accuracy using calibrated high precision instruments.
Nevertheless, I see that the sweet spot is at that 17500 feet altitude where they used WOT essentially eliminating the pumping loads, something the Diesels share at all power levels and altitudes, 300 LOP that is a mixture level shared by design by Diesels (and beyond 300 LOP) at all power settings and altitudes without any high tech equipment. With a comparable diesel engine in the same conditions, thermodynamics suggests that due to the fact that the compression ratio is more than twice that of the O-200, more energy would be transformed into mechanical energy per pound of fuel, therefore likely a better SFC.
FG
As you know the SFC of Diesels are fairly constant over the idle-TO power range, that without any fancy leaning procedures and at one sweet spot.
TBO wise, at the higher power densities diesels have to revert to non-casting technologies to achieve proper reliability due to better material choices availability and dimesional control. Nevertheless, I remember that with the SMA engines our TBO engine was dismanteled every 1000 hours without showing any wear of any of the parts in the hot section area execpt maybe the heads but that was mainly due to supplier issues if I recall. The problems of these two diesel contenders were for most of them self inflicted due to their design experience infancy (I am sure Lyco and TCM were no better back then). The real problem with SMA in the TBO domain are the things around the hot section where the design, though good, needs to be optimized, but they were the first generation; A second generation is currently in the making (in this world vacuum you create always gets filled by the competition).
wrt the cost of the TAE engines, all I can say is that their OEM prices were substantially lower than those of the Lycomings and Continentals, not 3 times. You are probably referring to the retrofit FWF Kits with STCs that have to charge for a lot of installation NRE and a lot more installation parts and a/c Mods.
FG
Clearly to me at least, Thielert was selling these engines to Diamond well below the cost to manufacture them to hook them and promote them. There is simply no way these could be made in these quantities at the OEM prices given the complexity of the design and development costs.
Furthermore, 2 minutes with a calculator dividing the reported $250-300 million R&D costs on the 1.8 engine alone by the numbers sold to Diamond for the prices asked along with the massive numbers of warranty replacement engines and parts showed this exercise to be a big money loser and this did not include what must have been huge additional costs to develop and test the 2.0 and 4.0 engines. The "new" prices for 2.0 engines are probably what Thielert needed to be selling the 1.8 engines to Diamond for in the first place.
SMA is maybe pricing their engines realistically to make it a viable business and they are well in excess of comparable Lycoming and Continental engines.
The fact is today to develop and certify a new engine design, costs tens of millions typically (or hundreds), without military sales where price is not really important, per unit commercial cost is likely to be far higher than established designs from decades ago where R&D, certification and tooling costs were paid for long ago.
The Thielert deal was hyped to the max by the press and never delved into much on a real world or economic level until their collapse. It was all gee whiz- look at how cool this is. The reality for operators was far different. The engines were a costly disaster for Diamond owners.
Hopefully buyers have learned something from all this. Wait until these engines are developed and proven for a few years first before you commit. An engine that burns 20% less fuel but costs twice as much to buy in the first place and requires more maintenance is no bargain, especially when the company goes bankrupt.
I applaud new engine development as you know but the economic realities of this often overshadow the enthusiasm of the technical work. Wanting to believe in something new to be wonderful does not make it so.
It will be a long time before Deltahawk investors get their money back and they are at least going the smart way with military interest.
Statements at the 2007 SAE World Congress said that with technologies such as BMWs Valvetronic and DI, gasoline engines were poised to soon be close to par for SFCs to Diesel designs and a great future was seen there. Indeed, we see this today with substantial fuel economy gains using these technologies. The gap is closing rapidly on Diesel vs. gasoline SFCs in the automotive world.
All I'm saying is aero Diesel proponents have a lot to prove before I'll accept it as reality.
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clearly this is not the case, since at idle the BSFC is by definition, infinite, a divide by zero error, or whichever way you wish to look at it.
BSFC always degrades with decreasing load. On a gasoline engine, it does this much more quickly due to the increase in pumping work and deviation from optimal compression ratio. Running lean mitigates this to an extent, but you run into the lean combustible limit at some point and must throttle to reduce load further.
You are technically right wrt BSFC; Notwithstanding, one can say that though by definition the BSFC goes to infinite, using proper math at the limits the latter multiplied by zero+ BHP (idle) probably gives you back your idle fuel mass flow which based on a normal flight power profile does not mean much on the overall block fuel.
The money you are talking about probably is for the 1.7, 2.0, 3.2 and, 4.0 liters (maybe others) as well as the many STCs NRE, distribution network and, product support (if any !); The price to certain OEMs may have been low but we need to consider the source of certain major parts (Mercedes) that are mass produced with the consequent lower price vs typical high cost of the small production a/c parts. As we now know, there may also be other less glamorus business decisions that may have contributed to this downfall.
The cost of developping and certifying an aero engine is more like 25-35 M$ when you already master the key technology it is based on; The other big costs are marketing, distribution network, liability, engineering and, product support/continuing airworthiness, etc.; They may significantly vary if you are a newcommer (TAE, SMA, etc.) or you are already established in the market (Lyco, TCM, Diamond Aircraft/Austro Engines, etc.). It also greatly helps if you are or you use an already established and highly competent engine designer that has significant (like a lot) knowledge and experience of the technology you are using.
I agree with you, the ROI figures in the aero engine business is nothing but brilliant, but you have to be in it for the long run and, have deep...very deep pockets and very patient shareholders.
In my opinion, at least initially the aero diesels will be more popular in the high power range on high usage commercial/utility a/c in competing with the lower end power turboshaft engines which have BSFCs about twice those of the aero diesels while burning the same fuels and, having an acquisition cost higher than the aero diesels: There the ROIs, if any, will be the most appealing of the eligible power range and allow the establishement of that technolgy at all levels from design through customer support.
As for any products, the tenacity and vision of the developers are what makes this world to reach new milestones and achieve progress.
FG
I'd agree with you on this point.
I don't see Diesels successful in competing with a PT6 at all any more than the Orenda V8 was. This market has money for fuel and wants smooth, reliable turbine power. A 600-1000 hp Diesel would be immensely heavy. The reduced fuel load required might offset this weight of course but it is not likely that King Air users would buy into the Diesel world IMO.
The TRACE-ORENDA engine in its current configuration is in my opinion outdated and, the turbine has an unquestionable reliability;
The cross over point for the turboshaft and aero diesel, i.e. where the total mission fuel (block fuel , alternate if required and, various reserves/contingencies) + powerplant mass, is at around 2.0 to 3.0 hours); Clearly not the short hop type mission in a suitable airport rich environment and, VFR.
By commercial/utility I did not mean any aero diesel would wipe out the turboshaft engines (especially above 750-1000 HP) but they could serve very well and present a definite appeal on many platforms like certain UAVs (typical mission is more than 3 hours), AG Planes could use the "inexpensive" AG Diesel fuels within their by definition typical low altitude/above gel point operational envelope, utility a/c especially in developing countries, replace some ageing radial engine applications, etc.
The parallel in the transport industry is the trucking and industrial applications which is mostly diesel and not generalized on MOGAS or turboshaft based powerplants.
Again, every type of engine has a niche market, though some smaller than others and changing with time as progress is made.
The cross over point for the turboshaft and aero diesel, i.e. where the total mission fuel (block fuel , alternate if required and, various reserves/contingencies) + powerplant mass, is at around 2.0 to 3.0 hours); Clearly not the short hop type mission in a suitable airport rich environment and, VFR.
By commercial/utility I did not mean any aero diesel would wipe out the turboshaft engines (especially above 750-1000 HP) but they could serve very well and present a definite appeal on many platforms like certain UAVs (typical mission is more than 3 hours), AG Planes could use the "inexpensive" AG Diesel fuels within their by definition typical low altitude/above gel point operational envelope, utility a/c especially in developing countries, replace some ageing radial engine applications, etc.
The parallel in the transport industry is the trucking and industrial applications which is mostly diesel and not generalized on MOGAS or turboshaft based powerplants.
Again, every type of engine has a niche market, though some smaller than others and changing with time as progress is made.
noinwe8uj2
I'm New Here
I know this post is a bit old, but are the deltahawks (US) now in the market and flying?
Dave_Boxall
Well Known Member
Correct me if I'm wrong...
Correct me if I'm wrong but I don't believe that there even one customer Deltahawk engine flying.
Dave
Correct me if I'm wrong but I don't believe that there even one customer Deltahawk engine flying.
Dave
I believe you are wrong, but can't swear to it.
It was my understanding that there was an early batch of motors delivered to customers for use on experimentals. They have also reportedly delivered many for a government contract for pilot-less drones.
The best way to get an answer would simply be to call them and ask how long it will take them to deliver you an engine.
Here's a clip of the Deltahawk engine on a test stand.
http://www.youtube.com/watch?v=nz8jwrkD2EQ
I don't know the intended application or who/what ABC is, but I does look like a tractor config.
Speaking of tractor, it sure sounds like one at idle.
Once it spools up it seems to smooth out nicely, or at least the prop sound masks that London taxi rattle. It's also nice to see that it doesn't smoke too much, you can see the puff of rich burning diesel before the turbo has spooled up to lean it out. It probably smokes a bit at WOT though.
http://www.youtube.com/watch?v=nz8jwrkD2EQ
I don't know the intended application or who/what ABC is, but I does look like a tractor config.
Speaking of tractor, it sure sounds like one at idle.
Once it spools up it seems to smooth out nicely, or at least the prop sound masks that London taxi rattle. It's also nice to see that it doesn't smoke too much, you can see the puff of rich burning diesel before the turbo has spooled up to lean it out. It probably smokes a bit at WOT though.
This probably isn't Deltahawk themselves but one of the customers. And a tractor config is a "puller", the Velocity is a pusher.
A clue to its use was in the video tags, one of them was "blimp". There is a company called American Blimp Corporation and a blimp uses engine pods so I suppose that's the most likely explanation given the video's title.
A clue to its use was in the video tags, one of them was "blimp". There is a company called American Blimp Corporation and a blimp uses engine pods so I suppose that's the most likely explanation given the video's title.
These guys are using the deltahawk engine in their helicopter. I believe they have been doing some test flying.
http://www.deltahelicopters.com.au/
http://www.deltahelicopters.com.au/
Here's CEO Diane Doers giving an interview on the history and some stories from the development - such as the time it ran with the crank in three pieces!
http://www.eaa.org/video/timelessvoices.html?videoId=60637056001
http://www.eaa.org/video/timelessvoices.html?videoId=60637056001
No problem, it was a very interesting piece. And that whole interview series is excellent, I'm glad I found it. What a treat to hear Frank Borman talk about his first hairy crosswind landing!
But anyway, I'm spoiled rotten on information in this age so it feels strange that there isn't more information on the engine available. Might as well gather all the good bits in this thread. I'm pretty sure I've read every publication and every forum post about it. Deltahawk has been saying "we'll have an engine ready this year" for many years, when that "promise" goes undelivered it can only hurt their reputation.
But it's a sound design and I think it will be a good product. It'll be ready when it's ready. I know I'm not building anything for a few years still, so patience is a cheap virtue for me.
But anyway, I'm spoiled rotten on information in this age so it feels strange that there isn't more information on the engine available. Might as well gather all the good bits in this thread. I'm pretty sure I've read every publication and every forum post about it. Deltahawk has been saying "we'll have an engine ready this year" for many years, when that "promise" goes undelivered it can only hurt their reputation.
But it's a sound design and I think it will be a good product. It'll be ready when it's ready. I know I'm not building anything for a few years still, so patience is a cheap virtue for me.
No problem, it was a very interesting piece. And that whole interview series is excellent, I'm glad I found it. What a treat to hear Frank Borman talk about his first hairy crosswind landing!
But anyway, I'm spoiled rotten on information in this age so it feels strange that there isn't more information on the engine available. Might as well gather all the good bits in this thread. I'm pretty sure I've read every publication and every forum post about it. Deltahawk has been saying "we'll have an engine ready this year" for many years, when that "promise" goes undelivered it can only hurt their reputation.
But it's a sound design and I think it will be a good product. It'll be ready when it's ready. I know I'm not building anything for a few years still, so patience is a cheap virtue for me.
Interesting interview for sure. I'm not sure I'd call anything unproven a sound design. The fact that it has taken so long now likely means there have been many problems encountered along the way. Only many thousands of trouble free flight hours will confirm the robustness of the design and only when it's on the market will we see what the price will really be. It's a non-starter for the RV world at the present prices being circulated for all but the wealthiest diesel enthusiasts. The published SFC number comparisons and cost per hour numbers didn't make sense either. I wish they'd publish some realistic data if they have it.
Kudos to them for staying at it all this time but I could only guess that the development costs to date have been staggering and I question the economic viability of the whole project- what will the break even point be on production engines with regards to prices and quantities required? It seems this is headed towards a primarily military market where these questions are far less important.
I believe there is a long road and a long wait ahead still but nice at least to see and hear one running.
Thanks. Yes, I knew the engine had flown many years ago but it has now been about 15 years in development and still not being sold to the experimental or certified markets. My business background and the historical track record of new aero engine designs successfully reaching the market place leaves me skeptical that the DH will ever be a big player here in the civilian aircraft world. The certification process is usually the death knell financially. I hope to be proven wrong though!
David-aviator
Well Known Member
The interview with Diane Doers is long, some 27 minutes, but well worth the time to hear her perspective on developing this engine. The set backs along the road, like paying for 100 crankshafts and receiving 2, bring into focus the challenges a small company faces.
Her positive enthusiasm, not at all exaggerated but straight forward and honest, no doubt has sustained the effort and will continue to do so simply because it appears she will not give up. The set backs have been many but there have been no lives lost in the effort and when the engine is delivered, it will be as thoroughly researched and tested as anything can be.
I talked with someone in their company at OSH in 2002 about the engine in a RV and came away with the feeling it would happen soon - but of course it did not. That was a let down that would not go away just like with Zoch. I went with a Subaru instead and that too was a costly let down.
The interview has changed my feeling about Deltahawk. They are attempting to do it right and if Diane Doers remains on the scene, it just may happen.
Her positive enthusiasm, not at all exaggerated but straight forward and honest, no doubt has sustained the effort and will continue to do so simply because it appears she will not give up. The set backs have been many but there have been no lives lost in the effort and when the engine is delivered, it will be as thoroughly researched and tested as anything can be.
I talked with someone in their company at OSH in 2002 about the engine in a RV and came away with the feeling it would happen soon - but of course it did not. That was a let down that would not go away just like with Zoch. I went with a Subaru instead and that too was a costly let down.
The interview has changed my feeling about Deltahawk. They are attempting to do it right and if Diane Doers remains on the scene, it just may happen.
You're absolutely right. I should've said the concept and the theory is sound, how it actually turns out in practice is another matter. If they succeed in having it certified and get some OEMs onboard, homebuilders won't have to do the first leaps to find that out.
Delta Hawk and Cirrus
I also belong to the Cirrus forum and it looks like Delta Hawk has teamed up with Lo Presti to do the STC work. The install photos look awesome. It is a very clean design. They are sticking to the over 1,000NM, 196TAS, 600 lbs as advertised on the delta hawk site. What's nice is both RJ (owner of lo presti) and Dennis Webb are on the site.
I also belong to the Cirrus forum and it looks like Delta Hawk has teamed up with Lo Presti to do the STC work. The install photos look awesome. It is a very clean design. They are sticking to the over 1,000NM, 196TAS, 600 lbs as advertised on the delta hawk site. What's nice is both RJ (owner of lo presti) and Dennis Webb are on the site.
Time to reopen this thread...
My question is directed at the guys who actually paid a deposit to DeltaHawk in 2003/2004.
My deposit was accepted at Sun 'n Fun 2004 with a promised delivery the following year.
I am still waiting.
Now I see, OSH2014, DeltaHawk are promising delivery 'next year' again; first for Experimentals, then STC's for certified aircraft.
I live in South Africa, am now retired, so the last time I was at OSH was in 2009 and then the price of the 'package' had jumped from the promised $25,500 to a mind boggling $65,000.
Can someone let me know what the projected delivery price will be 'next year.?'
My question is directed at the guys who actually paid a deposit to DeltaHawk in 2003/2004.
My deposit was accepted at Sun 'n Fun 2004 with a promised delivery the following year.
I am still waiting.
Now I see, OSH2014, DeltaHawk are promising delivery 'next year' again; first for Experimentals, then STC's for certified aircraft.
I live in South Africa, am now retired, so the last time I was at OSH was in 2009 and then the price of the 'package' had jumped from the promised $25,500 to a mind boggling $65,000.
Can someone let me know what the projected delivery price will be 'next year.?'
