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#31
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"Lonnie" @_#~#@.^net wrote in :
"Bertie the Bunyip" wrote in message ... Power/mercy snip - Bertie What a load of bull****. Nope. Efficiency is directly related to mission profile. That's not a spin, is frigging verbal lomcevak. If I didn't know better, I would suspect Anthony was forging your post. Of course you would. Since you're an idiot, you couldn't understand any of it. Since you're an idiot, you can't differenatiate between someone who has a pretty good idea of what he's talking about and a not-even- wannabe. it's just who you are. Be proud, k00k. Bertie |
#32
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"Lonnie" @_#~#@.^net wrote in :
"Bertie the Bunyip" wrote in message ... They do actually, and they can be very efficient indeed. http://www.youtube.com/watch?v=Nxz1UF67EQI There's also been the Dyke Delta, and the facetmobile, of course. Bertie Why would the Buttlipps be promoting the flying HEEL? Professional courtesy? Kindred spirit? Name association? Nope, thoght you must be quite familiar with their properties from being stepped on. Bertie |
#33
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a wrote in
: On Sep 6, 11:15*am, Leviterande Leviterande. wrote: Actually in teh begining of the * last century many designers started building circular aircraft, and all teh reports indicated that the flying *saucer had advantages as : easy and slow to fly almost impossible to stall highly crash proof cheap easy to manufacter if you dont think that is efficieny then I dont know what it is i read also in leonard G cramps books that during early wing tunnel tests the standard wing were *""retricted to be tested with * very limited AOA"" unlike the circular wings taht have been tested in extreme angles of attack without stall!! well, it is been a little offtopic but lets take a look at this propeller I found and it is patented 2008 it is easy to *contruct too what do you think? http://www.freepatentsonline.com/739...linkgrinder.co m/P atents/Divided_blade_r_7396208.html 'Lonnie[_3_ Wrote: ;659369']"Bertie the Bunyip" wrote in message .. .- They do actually, and they can be very efficient indeed. http://www.youtube.com/watch?v=Nxz1UF67EQI There's also been the Dyke Delta, and the facetmobile, of course. Bertie - Why would the Buttlipps be promoting the flying HEEL? Professional courtesy? Kindred spirit? Name association? -- Leviterande "Efficiency" in the sense I am using it is in the conventional engineering terms -- power out divided by power in. to do what? Travel a distance? Make a top speed? Rate of climb? That's the point I was making. I was alos using the smae yardstick, just not for one particualr mission, and high aspect ratio wings do not deliver in every case. Bertie |
#34
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a wrote in
: On Sep 6, 5:24*pm, Bertie the Bunyip wrote: a wrote innews:3bdcc9b5-67cc-4c34-a7a2-41e2a744b82d@z 72g2000hsb.googlegroups.com: On Sep 6, 5:41*am, Bertie the Bunyip wrote: a wrote innews:14d9aabc-33a9-4fdf-9ca5-78e407249a02@7 9g2000hsk.googlegroups.com: On Sep 6, 3:51*am, Bertie the Bunyip wrote: a wrote in news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424 @x35g2000hsb.googlegroups.com: On Sep 5, 6:46*pm, Leviterande Leviterande. wrote: Now woludnt a shorter prop with a bigger chord(and q-tips) move more a ir and thus creating equal thrust as a longer propeller with thinner chor d? when I tried the patented fan it was pretty quiet *however. How did you try the patented fan? AS for longer chords? Probably not. Think of the *most efficien t wing s for airplanes -- the ones that provide the best lift/drag. They are long and slender. The same principles hold for props. You can be sure if wide chords were better they'd be showing up on experimental aircraft, and they are not. They do actually, and they can be very efficient indeed. http://www.youtube.com/watch?v=Nxz1UF67EQI There's also been the Dyke Delta, and the facetmobile, of course. Bertie I don't think you'd find these as 'efficient' as conventionally shaped aircraft, else we'd be seeing competition gliders shaped this way. Those airplane shapes would have very light wing loading of course, but huge wetted areas -- think drag. Yeah, I understand al of that, but the word efficient is one that is often bandied as some sort of standard, but is just as misunderstood. While I know you mean aerodynamic efficiency in it's purest form, the mission is the yardstick by which you must measure the success of an airplane. Gliders are good at what they do, but they're as much a compromise as any other type of airplane. Low aspect ration machines have a few enormous advantages, not the least of which is a huge speed range and relatively low drag at low alpha. Span loading is more relevant than area loading in many ways and application, depending on what you're trying to get the wing to do at any given momen, and a low span loading, as in a glider, has to be paid for with *drag just like any other aerodynamic benifit. Simply put, the longer the span, the more air you're moving around. Now, for some applications, this is more efficient, since by agitating a greater volume air in a less agressive fashion than a little air, you may, and may is the operative word here, create less drag in your flight situation. . As for using that concept for prop blade shape, , where efficiency is defined in the conventional engineering sense as power out divided by power in, long and thin blades seem to win over short and fat. Depends on the application and what you're asking the blade to do. Length brings its own problem here again, but in spades, since tip speeds, particulalry at high cruise speeds, becomes a problem. There simply are no pat answers in aerodynamics. "Monoplanes are more efficient than biplanes" for instnace, is an oft touted example. Simply not true in every aspect. It depends on what you're asking the airplane to do. Of course, particualrexamples may be plucked from the air to prove almost any POV here. You could look at two types of aircraft and compare their performance with a single yardstick, such as fuel burn, but that doesn't make one more efficient than another as whole. just on fuel burn. If the fuel efficient one can't get out of the 800 foot strip it's parked in and the other one can, then the one that can is the more efficient machine for it's mission. That's not to say some airplanes aren't just plain inefficient, but it is a bit ridiculous to say that just because there's a popular mission and most airplanes tend to gel in that corner of design that those types of aircraft are ultimatley the most efficient things in the sky. Bertie The mission that seems best served by short span broad chord propellers seems to be in the marinas -- long and thin are not popular there. Even that may be changing, you may have seen a satellite view of an Ohio class submarine with its screw exposed recently (the navy goofed, those things are usually shrouded when they would be otherwise exposed) *and it looked like something that belonged on an airplane. Well, my main drive has short span long chord blades. So do most high bypass fan jets... Bertie early on I mentioned relatively low speed GA airplanes, and for sure recognize the difference fan jets provide. I'm sure you recognize that the high bypass stuff you drive is a different animal, and really not unlike the ducted fan with lots of hardware overhead I also mentioned. Get thy tongue from thy cheek! Your digression was from Anthony's manual. Not really. In fact I wondered if you might be an anthony sock for a bit! I just have a bee in my bonnet about emprical statements! You're not wrong about high aspect ration wings, but you're not completely right either. You're not going to win a soaring competition with an airplane with a 1-1 aspect ratio doesn't mean youcan't make it do something quite respectable. That Arup had some remarkable performance figures. They were far from just being a curiosity in the thirties when they were built. They got a lot of attention in the aviation press and the performance was remarkable. I have some of them somewhere but just going from memory the small engined ones, I think it had a 75 HP LeBlond on it, had a speed range of something like 30-120 MPH. They have some serious drag issues at low speeds, of course, but this can be turned to advantage, giving a steep approach so desirable in stol ops. This is the reason the Navy were interested in the Flying Flapjack airplanes in the mid 40s. Potentially good carrier airplanes with a very high cruise speed. Bertie |
#35
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On Sep 7, 3:23*am, Bertie the Bunyip wrote:
a wrote : On Sep 6, 5:24*pm, Bertie the Bunyip wrote: a wrote innews:3bdcc9b5-67cc-4c34-a7a2-41e2a744b82d@z 72g2000hsb.googlegroups.com: On Sep 6, 5:41*am, Bertie the Bunyip wrote: a wrote innews:14d9aabc-33a9-4fdf-9ca5-78e407249a02@7 9g2000hsk.googlegroups.com: On Sep 6, 3:51*am, Bertie the Bunyip wrote: a wrote in news:e5fb9dcd-6bd8-42e3-9a50-f6370d188424 @x35g2000hsb.googlegroups.com: On Sep 5, 6:46*pm, Leviterande Leviterande. wrote: Now woludnt a shorter prop with a bigger chord(and q-tips) move more a ir and thus creating equal thrust as a longer propeller with thinner chor d? when I tried the patented fan it was pretty quiet *however. How did you try the patented fan? AS for longer chords? Probably not. Think of the *most efficien t wing s for airplanes -- the ones that provide the best lift/drag. They are long and slender. The same principles hold for props. You can be sure if wide chords were better they'd be showing up on experimental aircraft, and they are not. They do actually, and they can be very efficient indeed. http://www.youtube.com/watch?v=Nxz1UF67EQI There's also been the Dyke Delta, and the facetmobile, of course. Bertie I don't think you'd find these as 'efficient' as conventionally shaped aircraft, else we'd be seeing competition gliders shaped this way. Those airplane shapes would have very light wing loading of course, but huge wetted areas -- think drag. Yeah, I understand al of that, but the word efficient is one that is often bandied as some sort of standard, but is just as misunderstood. While I know you mean aerodynamic efficiency in it's purest form, the mission is the yardstick by which you must measure the success of an airplane. Gliders are good at what they do, but they're as much a compromise as any other type of airplane. Low aspect ration machines have a few enormous advantages, not the least of which is a huge speed range and relatively low drag at low alpha. Span loading is more relevant than area loading in many ways and application, depending on what you're trying to get the wing to do at any given momen, and a low span loading, as in a glider, has to be paid for with *drag just like any other aerodynamic benifit. Simply put, the longer the span, the more air you're moving around. Now, for some applications, this is more efficient, since by agitating a greater volume air in a less agressive fashion than a little air, you may, and may is the operative word here, create less drag in your flight situation. . As for using that concept for prop blade shape, , where efficiency is defined in the conventional engineering sense as power out divided by power in, long and thin blades seem to win over short and fat. Depends on the application and what you're asking the blade to do. Length brings its own problem here again, but in spades, since tip speeds, particulalry at high cruise speeds, becomes a problem. There simply are no pat answers in aerodynamics. "Monoplanes are more efficient than biplanes" for instnace, is an oft touted example. Simply not true in every aspect. It depends on what you're asking the airplane to do. Of course, particualrexamples may be plucked from the air to prove almost any POV here. You could look at two types of aircraft and compare their performance with a single yardstick, such as fuel burn, but that doesn't make one more efficient than another as whole. just on fuel burn. If the fuel efficient one can't get out of the 800 foot strip it's parked in and the other one can, then the one that can is the more efficient machine for it's mission. That's not to say some airplanes aren't just plain inefficient, but it is a bit ridiculous to say that just because there's a popular mission and most airplanes tend to gel in that corner of design that those types of aircraft are ultimatley the most efficient things in the sky. Bertie The mission that seems best served by short span broad chord propellers seems to be in the marinas -- long and thin are not popular there. Even that may be changing, you may have seen a satellite view of an Ohio class submarine with its screw exposed recently (the navy goofed, those things are usually shrouded when they would be otherwise exposed) *and it looked like something that belonged on an airplane. Well, my main drive has short span long chord blades. So do most high bypass fan jets... Bertie early on I mentioned relatively low speed GA airplanes, and for sure recognize the difference fan jets provide. I'm sure you recognize that the high bypass stuff you drive is a different animal, and really not unlike the ducted fan with lots of hardware overhead I also mentioned. Get thy tongue from thy cheek! Your digression was from Anthony's manual. Not really. In fact I wondered if you might be an anthony sock for a bit! I just have a bee in my bonnet about emprical statements! You're not wrong about high aspect ration wings, but you're not completely right either. You're not going to win a soaring competition with an airplane with a 1-1 aspect ratio doesn't mean youcan't make it do something quite respectable. That Arup had some remarkable performance figures. They were far from just being a curiosity in the thirties when they were built. They got a lot of attention in the aviation press and the performance was remarkable. I have some of them somewhere but just going from memory the small engined ones, I think it had a 75 HP LeBlond on it, had a speed range of something like 30-120 MPH. They have some serious drag issues at low speeds, of course, but this can be turned to advantage, giving a steep approach so desirable in stol ops. This is the reason the Navy were interested in the Flying Flapjack airplanes in the mid 40s. Potentially good carrier airplanes with a very high cruise speed. Bertie If you associate me with Mx your judgment is seriously impaired. Keep an eye on that, and if the manifestations continue seek some professional help before it's too late. I seriously doubt the form factors those airplanes suggest for props would lead to any improvement in propeller efficiency, using the classical (energy out over energy in) definition. If they did, hanging one on a C152, C172, or a P140 would improve things like rate of climb or service ceiling or fuel economy (my Mooney gets about 18 mpg) by about the the same percentage as increased efficiency. There would be a nice market for such an improvement. My prediction is we'll continue to see only narrow chord blades in front of us for the next 15 years. |
#36
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Hi everybody, I just really wish I could view your intersting replies without the very very long "quotes" that come automaticly.. so could you please just delete the unnessesary quotos ?
any way.. the efficiency right now for me is the developed "static thrust" per horsepower" helicopter are good at but their complicated cyclcic and collective mechanincs and the very huge rotors takes down the efficiency( my opinion only) so what i am simply looking for is a simple propeller that is shafted to a motor (with or without gears) that is not too large for its thrust.. q-tips propellers are coming closer to that and that is why the fan I made with side portions was quite compared to other conventional rc propellers did you check this?: http://www.linkgrinder.com/Patents/D...r_7396208.html it is new and simple propeller claimed to produce 200 pounds of static thrust at a 85cm diamter with a 30hp! as i said I would appreciate if we could talk about efficieny of propellers thanx Kalle |
#37
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On Sep 7, 9:15*am, Leviterande Leviterande.
wrote: Hi everybody, I just *really wish I could view your intersting replies without the very very long "quotes" that come automaticly.. so could you please *just *delete the *unnessesary quotos ? any way.. the efficiency right now for me is the developed "static thrust" per horsepower" *helicopter are good at but their complicated cyclcic and collective mechanincs and the very huge rotors takes down the efficiency( my opinion only) *so what i am simply looking for is a simple propeller that is shafted to a motor (with or without gears) that is not too large for its thrust.. q-tips propellers are coming closer to that and that is why the fan I made with side portions was quite compared to other conventional rc propellers * did you check this?:http://www.linkgrinder.com/Patents/D...r_7396208.html it is new and simple *propeller claimed to produce *200 pounds of static thrust at a 85cm diamter with a 30hp! as i said I would appreciate if we could *talk about *efficieny of propellers thanx Kalle Leviterande wrote it is new and simple propeller claimed to produce 200 pounds of static thrust at a 85cm diamter with a 30hp! Thrust has nothing to do with efficiency. If the engine weighed 200 pounds it develops 200 pounds of thrust downward just sitting there. Horsepower measures work, in common units that would be about moving 33000 pounds a foot every minute (I may be wrong about that number). You told us the work going in -- that's 30 hp. What is the work coming out? Maybe you should define your problem or issue differently. It now seems to be you're trying to do something with an RC model. What exactly is your objective? Tell us that, and you'll have a better chance at getting a useful answer. My understanding is that RC models have power to burn -- way more than scale -- but my knowledge of that world is very limited. Y |
#38
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![]() "Bertie the Bunyip" wrote in message ... to do what? Travel a distance? Make a top speed? Rate of climb? That's the point I was making. I was alos using the smae yardstick, just not for one particualr mission, and high aspect ratio wings do not deliver in every case. Bertie Bull****, you are just trolling and trying to drift the thread. Get lost lamer. |
#39
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![]() "Bertie the Bunyip" wrote in message ... You are truly a wonder. Bertie Maybe to you, buy you seem to wonder about a lot of things. |
#40
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![]() "Bertie the Bunyip" wrote in message ... Of course you would. Since you're an idiot, you couldn't understand any of it. Since you're an idiot, you can't differenatiate between someone who has a pretty good idea of what he's talking about and a not-even- wannabe. it's just who you are. Be proud, k00k. Bertie Nonsense Kaptain Klueless, I know exactly that you are nothing but a wanna be troll. |
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