Wankel Engines Project Report edited .pdf - 123SeminarsOnly

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crankshafts. The redline of a rotary engine is limited by wear of the synchronizing gears. Hardened steel gears are used for extended operation above 7000 or 8000 rpm. Mazda Wankel engines in auto racing are operated above 10,000 rpm. In aircraft they are used conservatively, up to 6500 or 7500 rpm. However, as gas pressure participates in seal efficiency, running a Wankel engine at high rpm under no load conditions can destroy the engine. Fig. 5 Currently very few major companies employ this engine in their models, Mazda being one of them. O.S. Engines, a Japanese model engine manufacturer, is the only company in the world to produce a Wankel rotary aircraft engine. APPLICATIONS OF THE WANKEL ENGINE AIRCRAFTS In principle, a Wankel engine should be ideal for light aircraft, as it is light, compact, almost vibrationless and has a high power-to-weight ratio. Further aviation benefits of a Wankel engine include: (i) rotors cannot seize, since rotor casings expand more than rotors; (ii) a Wankel is not susceptible to "shock-cooling" during descent; (iii) a Wankel does not require an enriched mixture for cooling at high power; (iv) having no reciprocating parts, it is less vulnerable to damage during "over-revving" (the main rev-limit being the strength of the main bearings). Unlike the case with cars and motorcycles, a Wankel aero-engine will (because of the time taken for pre-flight checks) inevitably be sufficiently warm before full power is asked of it. A Wankel aero-engine spends most of its working time at high power outputs, with little 8
idling, so peripheral ports are ideal; and this makes feasible modular engines with more than two rotors. If "carb-icing" is an issue, plenty of waste engine heat is available to prevent trouble. Fig. 6 Aircraft using twin rotor Wankel engine Aircraft Wankels have made something of a comeback in recent years. None of their advantages have been lost in comparison to other engines. They are increasingly being found in roles where their compact size and quiet operation is important, notably in drones, or UAVs (Unmanned Aerial Vehicles). Many companies and hobbyists adapt Mazda rotary engines (taken from automobiles) to aircraft use; others manufacture Wankel rotary engines dedicated for the purpose. Wankel engines are also becoming increasingly popular in homebuilt experimental aircraft. Most are automobile engines, converted to aviation use. This is a very cost-effective alternative to certified aircraft engines, providing engines ranging from 100 to 300 horsepower (220 kW) at a fraction of the cost of traditional engines. These conversions first took place in the early 1970s. With a number of these engines mounted on aircraft, as of 10 December 2006 the National Transportation Safety Board has only seven reports of incidents involving aircraft with Mazda engines, and none of these were a failure due to design or manufacturing flaws. Peter Garrison, Contributing Editor for Flying magazine, has said that "the most promising engine for aviation use is the Mazda rotary." Mazdas have indeed worked well when converted for use in homebuilt aircraft. However, the real challenge in aviation is producing FAA-certified alternatives to the standard reciprocating engines that power most small general aviation aircraft. Mistral Engines, based in Switzerland, developed purpose-built rotaries for factory and retrofit installations on certified production aircraft. Mistral claims to have overcome the challenges of fuel consumption inherent in the rotary, at least to the extent that the engines are demonstrating specific fuel consumption within a few points of reciprocating engines of similar displacement. While fuel burn is still marginally higher than traditional engines, it is outweighed by other beneficial factors. 9
Page 1 and 2: PROJECT REPORT Application of Wanke
Page 3 and 4: IMPROVEMENT OF GAS SEAL ...........
Page 5 and 6: housing and a rotor that is similar
Page 7: Fig. 3 While a four-stroke piston e
Page 11 and 12: DISADVANTAGES OF WANKEL ENGINES The
Page 13 and 14: SEALING The gas sealing mechanism f
Page 15 and 16: Fig. 11 INTAKE AND EXHAUST MECHANIS
Page 17 and 18: Fig. 14 Fig. 15 Therefore, an appro
Page 19 and 20: Fig. 18 Fig. 19 The discharge of th
Page 21 and 22: consumption in an automobile and th
Page 23 and 24: determined to secure sufficient ope
Page 25 and 26: Fig. 30 Fig. 31 Fig. 32 The LDR rot
Page 27 and 28: (2) DETERIORATION OF LIGHT-WAD DRIV
Page 29 and 30: The amount of NO emission is decrea
Page 31 and 32: LOCATION AND NUMBER OF SPARK PLUGS
Page 33 and 34: exhaust gas temperature as high as
Page 35 and 36: port opening time and eliminating o
Page 37 and 38: STRATIFIED CHARGE TYPE ROTARY ENGIN
Page 39 and 40: Also, a multi-rotor engine with mor

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