09-03-2012, 04:20 PM
Six-stroke IC Engine:
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Introduction:
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber during the final stage of compression. Diesel engines have wide range of utilization for automobiles.
In this seminar we discuss about the six stroke engine. It include Introduction, the types of six stroke engine than how to work this six stroke, Factors contributing to increased thermal Efficiency, Reduced Fuel Consumption and Pollutant Emission of SIX STROKE I. C. ENGINE.
Analysis:
Six-stroke engine is mainly due to the radical hybridization of two- and four-strok technology. The six-stroke engine is supplemented with two chambers, which allow parallel function and results a full eight-event cycle: two four-event-each cycles, an external combustion cycle and an internal combustion cycle. In the internal combustion there is direct contact between air and the working fluid, whereas there is no direct contact between air and the working fluid in the external combustion process. Those events that affect the motion of the crankshaft are called dynamic events and those, which do not effect are called static events.
6.Engine parts modified :
6.1 Camshaft / Crankshaft Sprockets:
Crank has 1080 degrees of rotation for 360 rotation of camshaft
Hence their corresponding sprockets are having teeth ratio 3:1
34 teeth sprocket of camshaft in the four stroke is replaced by 42 teeth sprocket
17 teeth crankshaft sprocket is replaced by 14 teeth sprocket
6.2.Cam lobes:
360 degrees of cam has divided into 60 degrees among six strokes
Inlet valve is opened in the first stroke only and the exhaust valve, in the fourth, fifth and sixth strokes by the exhaust valve cam.
The exhaust valve cam is double lobed
6.3.Valve Timing:
IVO at 0 degree at TDC
IVC at 25 degree after BDC
EVO at 0 degree at BDC which was 25 degree before BDC in the original engine
EVC at 10 degree before TDC
Air inlet reed valve is opened in the fifth stroke and then for the sixth stroke exhaust valve is opened
7. Advantages:
Reduction in fuel consumption .
Better scavenging and more extraction of work per cycle .
Lower engine temperature - easy to maintain the optimum engine temperature level for better performance .
8. Disadvantages:
Dramatic reduction in pollution.
Liquefied Petroleum Gas.
Cost of a six-stroke engine is more.