A 6 Stroke Engine - an Innovation in Autuomotive Industry

SIX STROKE ENGINE:

AN INNOVATION IN AUTUOMOTIVE INDUSTRY

ABSTRACT

The increasing demands for low emissions and low fuel consumption in modern combustion engines requires improved methods for combustion process. The Beare Head is a new type of six-stroke engine head design known as the "Beare Head" after its designer, Malcolm Beare. The Beare Head uses a piston and ports very much like a two stroke engine to replace the overhead valve system that is found in four stroke engines today. The four-stroke block, piston and crankshaft remain unaltered. This combination of two stroke and four-stroke technology has given the technology its name the "six stroke engine".

Six Stroke engine, the name itself indicates a cycle of six strokes out of which two are useful power strokes. According to its mechanical design, the six-stroke engine with external and internal combustion and double flow is similar to the actual internal reciprocating combustion engine. However, it differentiates itself entirely, due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: combustion and an air heating chamber, both independent from the cylinder. In this the cylinder and the combustion chamber are separated which gives more freedom for design analysis. Several advantages result from this, one very important being the increase in thermal efficiency.

It consists of two cycles of operations namely external combustion cycle and internal combustion cycle, each cycle having four events. In addition to the two valves in the four stroke engine two more valves are incorporated which are operated by a piston arrangement.

The Six Stroke is thermodynamically more efficient because the change in volume of the power stroke is greater than the intake stroke and the compression stroke. The main advantages of six stroke engine includes reduction in fuel consumption by 40%, two power strokes in the six stroke cycle, dramatic reduction in pollution, adaptability to multi fuel operation.Six stroke engine's adoption by the automobile industry would have a tremendous impact on the environment and world economy.

 INTRODUCTION:

The majority of the actual internal combustion engines, operating on different cycles have one common feature, combustion occurring in the cylinder after each compression, resulting in gas expansion that acts directly on the piston (work) and limited to 180 degrees of crankshaft angel.

According to its mechanical design, the six-stroke engine with external and internal combustion and double flow is similar to the actual internal reciprocating combustion engine. However, it differentiates itself entirely, due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: Combustion, does not occur within the cylinder but in the supplementary combustion chamber, does not act immediately on the piston, and it's duration is independent from the 180 degrees of crankshaft rotation that occurs during the expansion of the combustion gases (work).

The combustion chamber is totally enclosed within the air-heating chamber. By heat exchange through the glowing combustion chamber walls, air pressure in the heating chamber increases and generate power for an a supplementary work stroke. Several advantages result from this, one very important being the increase in thermal efficiency. IN the contemporary internal combustion engine, the necessary cooling of the combustion chamber walls generate important calorific losses.

 ANALYSIS OF SIX STROKE ENGINE:

Six-stroke engine is mainly due to the radical hybridization of two- and four-stroke 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.

VIEW OF A SIX STROKE ENGINE

 ANALYSIS OF EVENTS:

 External combustion cycle: (divided in 4 events):

No direct contact between the air and the heating source.

e1. (Event 1) Pure air intake in the cylinder (dynamic event).

e2. (Event 2) Compression of pure air in the heating chamber (dynamic event).

e3. (Event 3) Keeping pure air pressure in closed chamber where a maximum heat exchange occurs with the combustion chambers walls, without direct action on the crankshaft (static event).

e4. (Event 4) Expansion of the super heated air in the cylinder, work (dynamic event).

 Internal combustion cycle: (divided in 4 events)

Direct contact between the air and the heating source.

I1. (Event 5) Re-compression of pure heated air in the combustion chamber (dynamic event)

I2. (Event 6) Fuel injection and combustion n closed combustion chamber, without direct action on the crankshaft (static event).

I3. (Event 7) Combustion gases expanding in the cylinder, work (dynamic event).

I4.