Engine performance and pollutant emission of an SI engine using ethanol–gasoline blended fuels

A comprehensive chemical kinetic combustion model for the four butanol isomers

Engine performance and exhaust gas emissions of methanol and ethanol–diesel blends

http://maghaleh2012.persiangig.com/document/yasaman/ls4.pdf

The use of ethanol–gasoline blend as a fuel in an SI engine

The stricter worldwide emission legislation and growing demands for lower fuel consumption and anthropogenic CO2 emission require significant efforts to improve combustion efficiency while satisfying the emission quality demands. Ethanol fuel combined with gasoline provides a particularly promising and, at the same time, a challenging approach. Ethanol is widely used as an alternative fuel or an effective additive of gasoline due to the advantage of its high octane number and its self-sustaining concept, which can be supplied regardless of the fossil fuel. As a result, vast study has been carried out to study its effects on engine performance and emission. The first part of this article discusses prospect of fuel ethanol as a gasoline substitute. Then it discusses comparative physicochemical properties of ethanol and gasoline. The slight differences in properties between ethanol and gasoline fuels are enough to create considerable change to combustion system as well as behaviors of SI engines. These effects lead to several complex and interacting mechanisms, which make it difficult to identify the fundamentals of how ethanol affects NOx emission. After that, general NOx forming mechanisms are discussed to create a fundamental basis for further discussion. Finally, the article discusses different fuel composition, engine parameter and engine modification effects on NOx formation as well as mathematical approach for NOx prediction using ethanol.

Effect of ethanol–gasoline blend on NOx emission in SI engine

This paper reports on emissions levels for CO, NO{sub x}, and unburned fuel (UBF) from a stationary four-cylinder Chrysler engine measured under a variety of operating conditions for gasoline and three different 20 vol percent alcohol-gasoline blends. In tests of separate isobutanol, ethanol, and methanol blends, lower CO and CO{sub x} emissions were observed for the alcohol blends relative to gasoline, particularly for fuel-rich operation. Generally, on a volume (mole) basis unburned fuel emissions were highest for methanol blends and lowest for gasoline, but on a mass or OMHCE basis only small differences were noted. For a given fuel, the separate effects of engine speed, load, and equivalence ratio were examined.

Exhaust Gas Emissions of Butanol, Ethanol, and Methanol-Gasoline Blends

An apparatus and method effects the cyclical actuation of an actuation member. The apparatus can be driven by a crankshaft and has at least one dual-acting phasing apparatus with at least three rotatable mounted internally splined members and at least a first rotatably mounted, externally splined, flexible member having a portion thereof rotatably disposed within each of at least two of the internally splined members. One inner splined member can be connected nonrotatably to a first rotatable member such as an inner shaft, which is rotatably disposed within an outer shaft of a concentric camshaft. Another internally splined member can be nonrotatably connected to the outer shaft. Yet another internally splined member can be nonrotatably connected to a pulley wheel driven by the crankshaft. A fourth internally splined member can be connected to one of the other three internally splined members. A second externally splined, flexible member can be disposed with a portion thereof rotatably disposed within each of at least two of either the three or four internally splined members. Various configurations of cam members and camlobe members can be disposed as integral portions of the inner shaft and the outer shaft. The cam members can be fixed or variable, full width cam members or splittable cam members. More than one concentric camshaft can be controlled by a single dual-acting phasing mechanism. More than one dual-acting phasing mechanism can be used to control two camshafts, concentric or conventional.

/pdf/dual-acting-apparatus-for-variable-valve-timing-and-the-like-1ug7zikivl.pdf

Dual-acting apparatus for variable valve timing and the like

A method of attaining a desired engine performance comprises the steps of changing the angular position of a variable camlobe (or cam) member relative to a fixed camlobe (or cam) member from a first angular position to a second angular position. In changing from the first to the second angular position, the variable camlobe (or cam) member moves in a predetermined direction relative to the direction of rotation of a camshaft. The predetermined direction and the magnitude of the angular movement of the variable camlobe (or cam) member is dependent at least in part upon at least one desired operating condition of the engine. The method further comprises changing the angular position of both camlobe (or cam) members relative to a reference point of a drive pulley. This change in the angular position of both of the camlobe (or cam) members relative to the reference point involves movement of the camlobes (or cams) in a direction relative to the direction of rotation of a camshaft. The direction and magnitude of this movement is based at least in part upon at least one desired operating condition of the engine.

/pdf/method-for-continuous-camlobe-phasing-4g5u9fmh52.pdf

Method for continuous camlobe phasing

An actuating apparatus, which can be used to perform variable valve timing of the intake or exhaust valves of an internal combustion engine, includes a hollow shaft with at least one slot defined through a cylindrical wall. A movable cam member is disposed to project through the slot and is rotatable relative to the hollow shaft in a channel defined in the interior surface of the hollow shaft. A base circle band extends circumferentially around the outer surface of the hollow shaft between the endwalls of the slot. The exterior surface of the hollow shaft can define grooves which receive front or back ear members of the cam member. The exterior surface of the hollow shaft also can define recesses, which in some embodiments have bottom surfaces and in other embodiments have partial bottom surfaces or no bottom surface. The recesses can receive tongue members formed on the cam member. The cam member can be engaged by a cam follower that has a roller to engage the cam surface. When the length of the roller exceeds the width of the cam surface, base circle arcuate sections can be provided on the exterior surface of the hollow shaft to carry the roller across the exposed portion of the slot that exists between the endwall of the slot and the free end of the cam member. An inner shaft extends through an opening defined transversely through the cam member and nonrotatably engages same. The nose portion of the cam member can be defined by a rotatable roller. Twin cam members having identical cam surface profiles can be disposed side-by-side, with one cam member projecting through the slot and the other cam member secured to the outer surface of the hollow shaft. A single follower such as a tappet defining a circular cylindrical surface can be provided to engage both cam members and can be held nonrotatably.

/pdf/variable-valve-actuating-apparatus-4b6rpl96vl.pdf

Alvon C. Elrod

Papers

Exhaust Gas Emissions of Butanol, Ethanol, and Methanol-Gasoline Blends

Dual-acting apparatus for variable valve timing and the like

Method for continuous camlobe phasing

Variable valve actuating apparatus

Development of a Variable Valve Timed Engine to Eliminate the Pumping Losses Associated with Throttled Operation