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"Andrew Sarangan" wrote in message
oups.com... On Sep 10, 6:28 pm, "Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote: ... "Small Turbine" and "Gas mileage" - you only get one - the thermodynamics just don't support both without real exotic materials. Other than that, though... -- I have heard that argument many times, but I have never seen that thermodynamic argument presented. I just borrowed the book on Aircraft Gas Turbine Engines from the library and plan to read it to find out what the real story is. My suspicion is that the limitation is in the materials, not thermodynamics. It may take a significant investment, That's why I said "without real exotic materials" The materials limit the maximum termperatures. The maximum temperatures limit the maximum efficiency. Also "small" (and I assume "reasonable cost") rule out regenerators to capture some of the waste heat (common on stationary applications) but if the military is also interested in similar things it won't be that hard to find the R&D suppport. I've heard that small turbines are of interest to the Air Force for potential use in UAVs. A UAV and a small GA airplane are not that far apart. In fact, the predator is True, but the military tends to care less about fuel cost and more about being able to use the same fuel in everything so if you have fuel, you have fuel. There were a number of programs in the 60's for turbines and direct injection piston engines that would run on "any fuel' that was available... ... Having said that, I know of at least two companies working on small turbines. One is Innodyn, and the other one is M-dot. The latter one I believe has some DoD contracts to be build turbines for UAVs. I doubt these companies would even exist if the basic physics is flawed. Nothing wrong with the physics. Small turbines work. And for some applications they have big adavantages. Fuel quantity per horsepower-hour, however, isn't one of them. -- Geoff The Sea Hawk at Wow Way d0t Com remove spaces and make the obvious substitutions to reply by mail When immigration is outlawed, only outlaws will immigrate. |
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On Sep 10, 7:43 pm, "Matt Barrow"
wrote: Possibly our own Mxmaniac is more representative of the current generation than we realize. By the way, cheap intergenerational shots don't help to bring in new customers, either! -- dave j |
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As I look at a high-school parking lot, there's so many cars I and
friends in "my day" would not be seen dead in. If this translates to airplanes, yoots today may not be interested in this kind of machinery. It's even true for older people, where so many SUVs have zero styling, and few convertibles or sport models available and sold in high numbers. F-- |
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On Mon, 10 Sep 2007 14:42:16 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in : While I agree that we need a modern aircraft at a "reasonable price" let's keep in mind that the vast majority of youngsters that you think are choosing not to fly because of the technology have never been close enough to the current airplanes to even see the technology. So the next time the local municipal airport holds an open house for the public, they should be sure ample leaflets are available at the local K-12 student campuses. Even better would be a brief presentation personally inviting everyone to take a reasonably priced introductory flight. And there need to be large 'Public Welcome' banners flying around the airport to attract motorists. Too often these sorts of inexpensive, but effective marketing are overlooked. From what I've seen, usually the attendance at these events is largely made up of aviators and others associated with the airport, not new blood. |
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On Mon, 10 Sep 2007 21:29:13 GMT, "Ken Finney"
wrote in : Aviation isn't exotic anymore, Perhaps not, but seed sown the magical moment when a kid experiences leaving the pavement during his first introductory flight in a Cessna 152 will blossom in the future when his situation is ready for it. |
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On Mon, 10 Sep 2007 23:42:21 -0000, Dave J
wrote in . com: I will tell you one thing that is not a solution: Cirrus aircraft and their like. GA is in a CLASSIC death-spiral: companies are moving to their high-end customers to maintain adequate margins. Cirrus's and others' $450k+ aircraft are not doing a damned bit to save GA. That sort of depends on how you define the future of GA. The FAA sees GA as a source of air-taxi passenger movers, so that airlines can utilize more airports. That is Cirrus' future market: air-taxi operators. |
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On Mon, 10 Sep 2007 17:06:34 -0700, Andrew Sarangan
wrote in .com: A small turbine may sound far fetched now, but ... There seem to be lots of small turbine engines available now, and they're getting bigger: http://www.gasturbine.pwp.blueyonder.co.uk/page2.htm Cobra Facts and Figures Thrust............................................ ....... ...163N Weight............................................ .........3.1 Kg Pressure ratio at max rpm.........................3.0 Max rpm..............................................1 05,000 rpm Idle speed............................................3 0,000 rpm Max exhaust gas temp..............................640 degrees C Mass flow.............................................. ..0.31 kg/s Specific Fuel Consumption (Propane).......0.8 Kg/N/Hr Lubrication.......Total loss system, Aeroshell 390 pressurised from compressor bleed. length including jet pipe............................444 mm Maximum width.......................................197 mm The Worlds Smallest Jet Aircraft Powered by two Cobra Engines -------------------------------------------------- http://www.gtba.co.uk/ THE GAS TURBINE BUILDERS ASSOCIATION http://www.gtba.co.uk/engine_designs...8e9bec894a 04 Homebuilt engine designs ------------------------------------- http://www.wrenturbines.co.uk/ http://www.wrenturbines.co.uk/product.php?pid=6 XL200 - AutostartStatistics Thrust 15kg (33lbs) Size 274mm x 120mm (11in x 4.8in) Weight 1800g (4lbs) Fuel Consumption 494ml/min Advanced Statistics Click Here Buy This Package Now for £2300 ------------------ http://www.swbturbines.com/ http://www.swbturbines.com/products/products.htm SWB-100SWB Proudly Announces the birth of our newest turbine the SWB-100. Actually producing 107 lb/ft thrust, this is one of the largest and most powerful turbines produced by SWB. This turbine is designed for professional large scale UAV applications. The engine has been extensively tested in our test cell using industry standard turbine testing procedures. The testing and qualification stages of this turbine engine are done. The engine is available for delivery, call today for more details. ----------------------------------------- http://www.heward-microjets.co.uk/en...wasp1h20.shtml WASP 1 H20 SPECIFICATIONS When correctly constructed: Max Thrust: 18-20 lb 8.1-9.07 kg Engine weight: 2 lb 950 gr Engine weight with starter: 2.4 lb 1090 gr Max RPM: 148,000 RPM Fuel consumption @ max RPM: 260 ml/min 200 gr/min Diameter: 3.74 in 95 mm Length: 6.69 in 175 mm Length with starter: 9.64 in 245 mm The Wasp 1 H20 is specially designed as a homebuild engine. The complete kit comes with a comprehensive and detailed Drawings and Instruction Manual which gives full instructions for the construction of each and every part of the engine. The construction manual can be purchased seperately and delivered by post or emailed as a PDF. If you do not wish to make the parts yourself, you may purchase them either individually or as a set. All parts are fully machined and ready for assembly. The price list of parts are as follows: ... The complete kit package comprising all parts required to build a Wasp 1 engine is priced at ONLY £899. This introductory offer is for a limited time only. Place your orders early to avoid disappointment. ------------------------------ http://www.amtjets.com/mk2hpes/mk2-hp.html Specifications Olympus HP E-start: Engine diameter: Engine length: Engine weight: Electronic Control Unit: Fuel pump: Gas bottle: Flight Battery: 2 solenoid valves: System airborne weight: 130 mm / 5.1 inches 375 mm / 14.7 inches 2850 Gram / 100 oz 110 Gram / 3.9 oz 170 Gram / 6.0 oz 95 Gram / 3.3 oz 350 Gram / 12.4 oz 80 Gram / 2.8 oz --------------------------------- 3685 Gram / 128.4 oz Thrust @ max. rpm@ STP (15 Deg.C/1013 Mbar): Maximum RPM: Idle RPM: Mass flow @ max. rpm: Normal EGT : Maximum EGT: Fuel consumption @ max. rpm: Fuel type: Throttle response from Idle RPM to Max RPM: Throttle response from 30% throttle to Max RPM: Throttle response from 50% throttle to Max RPM: E-start time: 23,5 Kilogram force / 51.7 Lbf 108,500 36,000 450 gr/sec. / 0.99 Lb/sec. 700 °C / 1290 °F 775 °C / 1380 °F 640 gr/min. / 22.5 oz/min. JP-4/paraffin/Jet A1, mixed with 4,5% Oil 3.5 Seconds. 1.5 Seconds. 0.5 Second. 10-15 seconds* * Fuel system primed from last engine run. Time measured from ignition to reaching idle RPM. Fully charged Nicad battery. Propane as starting gas. € 4.705,00 --------------------------------- |
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![]() "john smith" wrote in message ... In article . com, Andrew Sarangan wrote: - a small turbine engine suitable for GA aircraft with fewer moving parts and smoother operation I had a very good discussion at AirVenture 2007 with one of the people in the Williams tent. My question to him was what was Williams' side of the story with regards to the decision by Eclipse to drop their engine. The jist of his response was that Eclipse refused to accept that just because a jet engine is small doesn't mean it cost less than one a little bigger. That it could not develop the power/weight ration that the P&W did, in accordance with Eclipse's first request. That the Williams effort ran into numerous (?) problems pertaining to reliability, might have also been a factor. Sounds like Williams, great a company as they are, are making childish excuses for NOT PERFORMING. |
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![]() "Dave J" wrote in message ps.com... Maybe because they are overwhelmed with things to keep them entertained, 24x7, and we live in a socity in which challenging yourself is not encouraged. I think the armies of kids cramming for the SATs, busting their butts to get precious scholarships to get them through college without a debt, etc, are challenging themselves just fine. Really? How many is that? How many cramming for a test that's been dumbed down annually for thirty years? I don't know how old you are 52...been there. , but I hazard to guess that kids today are growing up in a more competitive environment than any time in modern history. A couple generations ago, half of kids went to college. Now everyone has to go, even though few are really qualfiied for a college curriculum. Note, too, how many college seniors can't pass a test that junior high kids did not too long ago. As for "competitive", that's the last things are faced with - every one gets a brass ring regardless of capability or effort. It's not challenge. If anything, it's risk/reward. And the challenge is applying and dealing with those risk factors. Oh, and by the way, you can kill yourself in an airplane, which, to my knowledge, has not happened with an iPod. Could be wrong on that. ![]() Well, you can certainly cook your brain matter. One key factor is the antiquated airplanes we fly. That might be part of it, but I'd say it was pretty much insignificant. The newer 172s and 182s are a good foundation, and even their costs are minor for a generation that thinks nothing of $150 sneakers, a $20000 Honda Civic with fart mufflers, $300 a wheel rims and other trim "features". Wha? that $150 pair of sneakers is going to get you what, 3/4 of an hour in a new 172? Around here, a two year old 172 goes for $105, wet. How many sneakers do you think kids today are buying? A lot more than they did when a pair of sneakers cost $15 and a 172 went $19/hr. My flying habit, at its max has been about 100 hours a year in 30-year-old 172's and Cherokees. That's been roughly $10,000/yr all told. That's the same cost as the Honda, *gone* in two years. At least with the Honda, you've got a car at the end of two years. You know, I _think_ you just showed the attitude that may be behind the dearth of new students. Look, I *love* aviation. I suspect you do, too. But I don't think we can build aviation's future on people who just love airplanes. Practical allpication helps. I've average 350 hours/year the past nine years. That's because I operate my business not as a local endeavor, but across about half a million suare miles. Couldn't do that by car, by airline, or even by the regionals. In sum, it's gives me a hell of an advantage over my competitors (there's that competition thing again) who want to still in their backwater towns and wait for business to knock on their doors. Only way it could be done is by GA airplne, but that vehilcle has to be very capable, reliable/dependable, and FAST. You need to get people who, well, just "kinda like" airplanes and might even find them useful sometimes. As above, the USEFUL is the key; there are , as I pointed out, so many other "hobbies" to participate in that are cheaper and, to someone NOT an airplane lover, jsut as rewarding. Yet, how rewarding is playing X-BOX? Possibly our own Mxmaniac is more representative of the current generation than we realize. He is somewhat, and I believe I am somewhat. I don't know mxmanic's background. I suspect he works in the computer business. I am a computer engineer (I don't program computers, I design their chips). I've worked hard to be skilled at my craft. In fact, I like becoming skilled at crafts. That's a lot of the fun for me -- hence aviation! But I struggle to find time and cash to keep this hobby up. You just hit on the major facet: COST. The other key word is: HOBBY. -- Matt Barrow Performance Homes, LLC. Cheyenne, WY |
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![]() "Dave J" wrote in message oups.com... On Sep 10, 7:43 pm, "Matt Barrow" wrote: Possibly our own Mxmaniac is more representative of the current generation than we realize. By the way, cheap intergenerational shots don't help to bring in new customers, either! With MX, there is no such thing as a Cheap Shot, intergenerational or otherwise. Even his peers in terms of age disdain and ridicule him. I think many, if not most, here don't want such a mentally defective lout in the REAL air with us. |
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