Van's Air Force
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Yet Another Diesel Startup.
- Thread starter Glovebox
- Start date
Interesting but pretty short on technical details. I always balk when people developing new engines start out by predicting huge TBOs before the design has even been flight tested, let alone having multiple examples actually prove these numbers in the real world. Highly unlikely that any new design will be achieving 4000-6000 hours on wing any time soon.
I'll be watching with interest to see where this one goes.
Skeptic
Oh, Ross! You're such a skeptic! Don't you know the Diesel is the answer to every motor-head's dream? They last 10s of thousands of hours and burn so little fuel that you have to drain the fuel once a year to fill the tanks with fresh stuff.
Seriousy, though, what galls my butt is when they make the comparisons between Diesel use vs avgas. They never tell you if the Diesel used much heavier Diesel fuel or kerosene, with their totally different BTU content, and how the plane, for a given fuel weight, has to carry fewer gallons, because of the heavier weight. I'd like to see them make their comparisons on BTU/HR or miles per BTU, then we'd see a lot lower difference which would just be to the higher efficiency from the higher CR and not the fuel. They also don't say a lot about the algae growth in the fuel or how it congeals at lower temps. Wouldn't it be nice if they told you the whole story rather than an ad-man's hype!
Oh, Ross! You're such a skeptic! Don't you know the Diesel is the answer to every motor-head's dream? They last 10s of thousands of hours and burn so little fuel that you have to drain the fuel once a year to fill the tanks with fresh stuff.
Seriousy, though, what galls my butt is when they make the comparisons between Diesel use vs avgas. They never tell you if the Diesel used much heavier Diesel fuel or kerosene, with their totally different BTU content, and how the plane, for a given fuel weight, has to carry fewer gallons, because of the heavier weight. I'd like to see them make their comparisons on BTU/HR or miles per BTU, then we'd see a lot lower difference which would just be to the higher efficiency from the higher CR and not the fuel. They also don't say a lot about the algae growth in the fuel or how it congeals at lower temps. Wouldn't it be nice if they told you the whole story rather than an ad-man's hype!
pierre smith
Well Known Member
That's why.....
...most of us don't even go there...same 'ol same 'ol.
Just a waste of Doug's bytes
Best,
...most of us don't even go there...same 'ol same 'ol.
Just a waste of Doug's bytes
Best,
Yeah, here we go again....
I know I don't "get it", but I do know this: I measure the economy of my diesel RV9 by my wallet. My plane burns an honest 4.8-5 GPM AVERAGE, including taxi, takeoff, climb, cruise. I know that on cross-country flights, my average cruise speed is 160 mph TAS. In the summer I burn diesel fuel, which costs me around $2.50/gal. In the winter, I burn Jet A, which costs me anywhere from $3.75 to $4.75/gal. Do the math - it's really cheap flying.
I really don't care about the extra weight of the fuel, since it just gives me more range. I look at is as a weight savings over long-range tanks. Yes, diesel gels when cold, but Jet A doesn't gel above -60C, which is too cold for me to fly in. This is why I use it in the winter, just to be safe.
I've seen lots of comments about Avgas engines being this economical, with plenty of math to support it, but it's always calculated at cruise, LOP, etc. I'm pretty sure that when you factor in the entire flight, it's not as good as it sounds. At least that's what many of my avgas-burning friends say... But for those who have tweaked their avgas engines to match the diesel's economy, I say "good for them", and applaud their success. Economy aside, though, I've got lots of diesel experience and believe that the good outweighs the bad, especially when it comes to safety.
But the bottom line is, avgas is on it's way out. There's no good alternative available yet, and when there is, you can be sure it will be very expensive. Diesel's coming, whether you're a "believer" or not. TCM and so many others wouldn't be investing so much in the technology if they didn't see it in the future. It may take awhile for it to become mainstream, but it will.
I do agree that there are too many start-ups with too many outrageous numbers, and not enough info or flight hours to back it up. In the end, only a few designs are going to make it. But - IMHO, the writing is on the wall, and the first company with the "right" engine is going to do well.
Until then, I've got 200 hours on mine, and it's working quite nicely. I wouldn't trade it for a Lyc or any other alt engine - for now, anyway.
Kurt
I know I don't "get it", but I do know this: I measure the economy of my diesel RV9 by my wallet. My plane burns an honest 4.8-5 GPM AVERAGE, including taxi, takeoff, climb, cruise. I know that on cross-country flights, my average cruise speed is 160 mph TAS. In the summer I burn diesel fuel, which costs me around $2.50/gal. In the winter, I burn Jet A, which costs me anywhere from $3.75 to $4.75/gal. Do the math - it's really cheap flying.
I really don't care about the extra weight of the fuel, since it just gives me more range. I look at is as a weight savings over long-range tanks. Yes, diesel gels when cold, but Jet A doesn't gel above -60C, which is too cold for me to fly in. This is why I use it in the winter, just to be safe.
I've seen lots of comments about Avgas engines being this economical, with plenty of math to support it, but it's always calculated at cruise, LOP, etc. I'm pretty sure that when you factor in the entire flight, it's not as good as it sounds. At least that's what many of my avgas-burning friends say... But for those who have tweaked their avgas engines to match the diesel's economy, I say "good for them", and applaud their success. Economy aside, though, I've got lots of diesel experience and believe that the good outweighs the bad, especially when it comes to safety.
But the bottom line is, avgas is on it's way out. There's no good alternative available yet, and when there is, you can be sure it will be very expensive. Diesel's coming, whether you're a "believer" or not. TCM and so many others wouldn't be investing so much in the technology if they didn't see it in the future. It may take awhile for it to become mainstream, but it will.
I do agree that there are too many start-ups with too many outrageous numbers, and not enough info or flight hours to back it up. In the end, only a few designs are going to make it. But - IMHO, the writing is on the wall, and the first company with the "right" engine is going to do well.
Until then, I've got 200 hours on mine, and it's working quite nicely. I wouldn't trade it for a Lyc or any other alt engine - for now, anyway.
Kurt
Diesels do seem to do the mission for less fuel burn costs but the whole thing from acquisition, maintenance and TBO and cost of overhaul is really what counts and those numbers are not in yet for aero diesels.
The Thielert and SMA engines were in no way less expensive per flight hour than their avgas competitors because the engines were expensive and had maintenance and structural issues.
I agree with Kurt though, the first company to get things right and prove it over the long term with a decent sized fleet will have a ready market.
Anyway, I still respect those who develop new engines for aircraft. Keeps life interesting and gives people new choices. If we don't try something new, we'll always be stuck with the same old. It just makes more sense to keep your mouth shut until you prove everything in real life first. Test, test, test.
The Thielert and SMA engines were in no way less expensive per flight hour than their avgas competitors because the engines were expensive and had maintenance and structural issues.
I agree with Kurt though, the first company to get things right and prove it over the long term with a decent sized fleet will have a ready market.
Anyway, I still respect those who develop new engines for aircraft. Keeps life interesting and gives people new choices. If we don't try something new, we'll always be stuck with the same old. It just makes more sense to keep your mouth shut until you prove everything in real life first. Test, test, test.
Too bad the article doesn't hint at the config, only that it will be easy to use, low priced, low consumption, low weight and (reading between the lines) that it will dispense gumdrops if flying over kindergartens.
Diesel has the inherent advantage of not being reliant on electric spark and having good low rpm torque. Yet factory installations such as Thielert and Diamond's new mill Austro are FADEC, reduction box configs. Forced induction and liquid cooling are complications enough in my opinion, mechanical injection and direct drive should be a given.
I know WAMs are direct drive but apart from the glow plugs I'm not sure they need electrons to inject fuel. Deltahawk certainly doesn't but obviously they need to get flying in a customer installation before the simpler design can be properly marketed to all the diesel thirsty European flying clubs.
Diesel has the inherent advantage of not being reliant on electric spark and having good low rpm torque. Yet factory installations such as Thielert and Diamond's new mill Austro are FADEC, reduction box configs. Forced induction and liquid cooling are complications enough in my opinion, mechanical injection and direct drive should be a given.
I know WAMs are direct drive but apart from the glow plugs I'm not sure they need electrons to inject fuel. Deltahawk certainly doesn't but obviously they need to get flying in a customer installation before the simpler design can be properly marketed to all the diesel thirsty European flying clubs.
Ron Lee
Well Known Member
Maybe...maybe not. Even if 100LL is gone in 20 years does not man that diesel is the primary GA fuel. If you do something to force a 100% conversion to diesel/Jet A you kill GA.
There is a reason that auto/truck engines are primarily gasoline in the USA. I don't know the reason but don't expect diesel to become the primary engine in the USA.
Assuming that these folks come up with a product. How long would reasonable people wait until buying one to let initial developmental problems get resolved and reliability established? 10 years, 15? 20?
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Too bad the article doesn't hint at the config, only that it will be easy to use, low priced, low consumption, low weight and (reading between the lines) that it will dispense gumdrops if flying over kindergartens.
Diesel has the inherent advantage of not being reliant on electric spark and having good low rpm torque. Yet factory installations such as Thielert and Diamond's new mill Austro are FADEC, reduction box configs. Forced induction and liquid cooling are complications enough in my opinion, mechanical injection and direct drive should be a given.
I know WAMs are direct drive but apart from the glow plugs I'm not sure they need electrons to inject fuel. Deltahawk certainly doesn't but obviously they need to get flying in a customer installation before the simpler design can be properly marketed to all the diesel thirsty European flying clubs.
Pretty well every diesel design in the last 20 years has been turbocharged because they have to be to generate useful torque, hp and power to weight ratios. The 2 stroke diesel is the best option for aircraft IMO to keep the weight reasonable as WAM has shown.
Well, here's where the WAM-120 could go with the right backing...
http://papers.sae.org/2010-01-2147
http://papers.sae.org/2010-01-2147
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I didn't mean to say that Jet A will be the primary fuel for GA, only that it would be mainstream.
IMHO the reason that AUTO engines are gasoline in the usa is that they are very quiet, very smooth, and reasonably efficient. They are also very reliable, durable, and they start / run well in all climates. What's not to like? We're willing to sacrifice a bit of economy for comfort, unlike the Europeans, who seem to favor diesel. But the primary fuel in the USA for TRUCKS 3/4 ton and over, is diesel. There is plenty of info in other threads that explain why. As Ross points out, it has much to do with turbocharging.
And you're right, it will take several years for a good diesel product to become mainstream, especially here in the US. Any mandate to convert the GA fleet to diesel / jet A would spell the end of GA, so it will have to come slowly, as new aircraft are brought to market.
Kurt
The only reason diesels have become so popular in Europe is from the massive fuel excise/tax subsidies in mainland Europe. I don't know what it's like now, but historically, diesel has been 50-70% of the price of gasoline in France, Germany, Italy and other places.
If this wasn't the case, Europe would still be as gasoline as the US is and common-rail diesel engine technology would be a passing note in a 1930's technology handbook... (yes really!)
If this wasn't the case, Europe would still be as gasoline as the US is and common-rail diesel engine technology would be a passing note in a 1930's technology handbook... (yes really!)
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This is true to some extent. But diesel and and gasoline are very close on the pump price right now. I can only speak for Norway but the pump prices are within 5-6%. If you fly a diesel you can buy agricultural diesel which doesn't include the road tax. The only difference between regular and agricultural is a green dye which authorities use to determine if cars are using it - also handy to spot leaks I suppose.
But you can do the same with Mogas, although I'm not 100% sure on the procedure. Basically you buy pump gas, keep the receipts and claim the road tax back later.
Jet A1 to private customers out of the airport pump is around 15-20% cheaper than road diesel with the road tax. I think agricultural diesel comes ahead but it does of course involve transporting fuel to the field.
So gas, diesel and Jet A1 are all taxed but historically gasoline was taxed the hardest, first. Once diesel caught on, it got hit by the tax stick as well. But none of them contain tetraethyl lead, which is the primary bane of 100LL.
Diesel engines run better with electronic injection control. From a smoother idle to greater power, efficiency and cleaner emissions. We have them at work.
In North America, Liquified Natural Gas (LNG) seems to be the available fuel of the future. (says T. Boone Pickens) With 'Gas to Diesel' refining; diesel aircraft engines might be OK.
I keep thinking MultiFuel is the future, with diesel compression ratio, direct injection and a spark plug but no throttle. Then a wider variety of liquid hydrocarbons would work well (think unleaded Mogas to Home heating oil). The engine sensor and control package would tune the engine for the fuel and the power demand. Every time a combustion event occurs, the controls would calculate an improved spark or mixture for the next event. Controlling ignition advance, injection advance and injection duration.
Simple diesel like WAM are great. They have the market, if they can fill it. The next will have to be better to survive. That's going to be hard.
In North America, Liquified Natural Gas (LNG) seems to be the available fuel of the future. (says T. Boone Pickens) With 'Gas to Diesel' refining; diesel aircraft engines might be OK.
I keep thinking MultiFuel is the future, with diesel compression ratio, direct injection and a spark plug but no throttle. Then a wider variety of liquid hydrocarbons would work well (think unleaded Mogas to Home heating oil). The engine sensor and control package would tune the engine for the fuel and the power demand. Every time a combustion event occurs, the controls would calculate an improved spark or mixture for the next event. Controlling ignition advance, injection advance and injection duration.
Simple diesel like WAM are great. They have the market, if they can fill it. The next will have to be better to survive. That's going to be hard.
The more I read what's in the science pipeline, the more I become convinced that diesel aircraft engines are simply a niche transitional product. I'm betting that batteries sufficient for cross-country flying will be available within a decade - or less time than I expect my current IO-320 to last.
smokyray
Well Known Member
Head of Steam
This prospect always intrigued me:
http://www.flixxy.com/besler-steam-airplane.htm
Smokey
HR2
RVX
.
This prospect always intrigued me:
http://www.flixxy.com/besler-steam-airplane.htm
Smokey
HR2
RVX
.
I think battery operation is the same as what you say for Diesel, a transitional product. I'm betting that the final thing in the future will be the fuel cell powering the much more efficient electric motor. The nice thing about a fuel cell is that it will be powered with a fuel that can be pumped into the tanks at your airport. Batteries are nice, but not very practical.
I would like to see develpment of an aircooled, direct drive, pushrod, flat 4 using mogas, direct injection, and full electronic ignition with the appropriate algorithms built in to automatically lean and richen when necessary. It would be light, cheap, reliable, and efficient.
Tim
Tim
You know, one of the things that is left out of this whole propulsion thing is that if you make a cleaner, lower drag airframe, and use a high efficiency prop, you can get along with less power and lower fuel burn. As Pat Panzera pointed out to me, if you notice, these electric-powered airplanes have a really efficient low-drag design and high-aspect ratio wings to lower parasite and induced drag. Using what you've written and combining with this is the better way to go!
ColoCardinal
Well Known Member
Diesel fuel in a plane?
I have a deisel tractor and know of that fuels pittfals. Diesel trucks need heaters in the fuel tanks and along the fuel lines if you want to run them in the winter (or fly to altitude). Storing diesel fuel for long can be a proble too because It will support mold growth wich will clog fuel injectors. Jet-A is more stable and less prone to these problems. that said, you'd still be pouring Prist into your tak in the winter; and now you're in a price range that's higher than Mogas again.
I have a deisel tractor and know of that fuels pittfals. Diesel trucks need heaters in the fuel tanks and along the fuel lines if you want to run them in the winter (or fly to altitude). Storing diesel fuel for long can be a proble too because It will support mold growth wich will clog fuel injectors. Jet-A is more stable and less prone to these problems. that said, you'd still be pouring Prist into your tak in the winter; and now you're in a price range that's higher than Mogas again.
Fuel Cells require some specific type of fuel (some even use gasoline), and ultimately require replacement of the catalyst (usually platinum, at platinum prices). Fuel is specific. Electricity is not, and can be obtained (indirectly, at least) from any "fuel" source (e.g. coal; nuclear; wind; solar; etc.). Thus, fuel cells are yet another way of locking us into a proprietary solution while batteries abstract us from the source of energy. Commodity energy is the ultimate goal from the Consumer standpoint, preventing cartels such as Opec from dictating your prices.
At some point batteries will become rather indistinguishable from capacitors in that their useful life will be relatively unlimited and the available current draw will be sufficient for sustained aircraft operations while allowing quick-charge or slow charge almost anywhere.
For quick charging, airfields will have a "battery tank" analogous to existing fuel tanks, and voltage adapters will allow tailoring volts/amps to the capabilities of the target aircraft. Voltage will likely be quite high to keep amps lower and allow smaller wires. Fillups will take about the same amount of time they take today, with no chance of spills.
At the end of the day (or millenium), physics dictates what is most efficient. Indefinite life batteries / capacitors (whichever develops the best energy density) will trump any system requiring greater complexity, such as fuel cells. The other big win will be that once solar cells break a certain level of efficiency at a certain manufacturing cost, they become cheaper than the cost of simply pumping oil out of the ground. Once that happens, NO ONE will bother with oil - except perhaps as a lubricant.
whats the difference in price now? that would be a fair gauge of how far off your "not bothering with oil" scenario will happen
If it will be possible in the future to get the energy density of batteries/supercaps, coupled with higher efficiency electric motors, to equal or exceed that of gasoline and an IC engine, along with the ability to "fill-up" immediately, that will be something to shoot for!
I'm still waiting to hear about the first people who get electrocuted by these high voltage batteries in cars or the caustic spill that will result in a collision. I know they are conducting schools for first-responders in how to handle batteries and wiring in electric cars. If you've ever seen what happens when you accidentally bridge the 12V battery terminals with a wrench, imagine the explosion that will result if you do the same with an over-200V battery. Our Radar-Computer Guidance station had dual 75kW battery-powered UPS and I was extremely careful around the batteries. I came to that caution from working on battery back-ups in central office telephone systems.
I'm still waiting to hear about the first people who get electrocuted by these high voltage batteries in cars or the caustic spill that will result in a collision. I know they are conducting schools for first-responders in how to handle batteries and wiring in electric cars. If you've ever seen what happens when you accidentally bridge the 12V battery terminals with a wrench, imagine the explosion that will result if you do the same with an over-200V battery. Our Radar-Computer Guidance station had dual 75kW battery-powered UPS and I was extremely careful around the batteries. I came to that caution from working on battery back-ups in central office telephone systems.
LNG is supposed to be North America's fuel of the future.
Fuel cells would run on it very nicely.
The dissadvantage would be fueling directly before the flight, although the fuel use rate would exceed the boil off even if the tanks weren't well insulated.
De-fueling unused LNG would be a pain however...
Fuel cells would run on it very nicely.
The dissadvantage would be fueling directly before the flight, although the fuel use rate would exceed the boil off even if the tanks weren't well insulated.
De-fueling unused LNG would be a pain however...
detlef lili
Well Known Member
Hi Kurt!
What engine model do you fly?
Detlef
What engine model do you fly?
Detlef
Dave_Boxall
Well Known Member
Kurt has a Wilksch WAM-120 diesel in his RV-9A.
Dave
Dave
