24-02-2011, 12:20 PM
PRESENTED BY:
SATYA PRAKASH
[attachment=9077]
6 STROKE ENGINE
THE SIX-STROKE ENGINE WITH EXTERNAL AND INTERNAL COMBUSTION AND DOUBLE FLOW CONCEPT
ABSTRACT
One of the most difficult challenges in engine technology today is the urgent need to increase engine thermal efficiency. This paper presents the six-stroke engine with external and internal combustion and double flow concept in the development of high-efficiency engines for the 21st century.
The majority of I.C.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 and limited to 180 degrees of crankshaft angle.
According to its mechanical design, the six-stroke engine is similar to the I.C.engine. It differs due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: a combustion and an air heating chamber, both independent from the cylinder. Combustion, doesn’t occur within the cylinder but in the supplementary combustion chamber, doesn’t act immediately on the piston, and its duration is independent from the 180 degrees of crankshaft rotation that occurs during the expansion of the combustion gases.
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.
Key words: Six stroke engine, external and internal combustion, heating chamber
1. INTRODUCTION
One of the most difficult challenges in engine technology today is the urgent need
to increase engine thermal efficiency. Thermal management strategies and the choice of fuels will play crucial roles in the development of high-efficiency engines for the 21st century.
However, it was during the 19th century that the fundamental principles governing the efficiency of internal combustion engines were first posited. In 1862, Alphonse Beau de Rochas published his theory regarding the ideal operating cycle of the internal combustion engine.
He stated that the conditions necessary for maximum efficiency were:
(1) Maximum cylinder volume with minimum cooling surface;
(2) Maximum rapidity of expansion;
(3) Maximum pressure of the ignited charge and
(4) Maximum ratio of expansion.
Beau de Rochas' engine theory was first applied by Nikolaus Otto in 1876 to a four-stroke engine of Otto's own design. The four-stroke combustion cycle later became known as the "Otto cycle".
In the Otto cycle, the piston descends on the intake stroke, during which the inlet valve is held open. The valves in the cylinder head are usually of the poppet type. The fresh fuel/air charge is inducted into the cylinder by the partial vacuum created by the descent of the piston. The piston then ascends on the compression stroke with both valves closed and the charge is ignited by an electric spark as the end of the stroke is approached. The power stroke follows, with both valves still closed and gas pressure acting on the piston crown because of the expansion of the burned charge. The exhaust stroke then completes the cycle with the ascending piston forcing the spent products of combustion past the open exhaust valve. The cycle then repeats itself.
Each Otto cycle thereby requires four strokes of the piston- intake, compression, power and exhaust- and two revolutions of the crankshaft.
The disadvantage of the four-stroke cycle is that only half as many power strokes are 2 completed per revolution of the crankshaft as in the two-stroke cycle and only half as much power would be expected from an engine of given size at a given operating speed. The four-stroke cycle, however, provides more positive scavenging and charging of the cylinders with less loss of fresh charge to the exhaust than the two-stroke cycle. Modern Otto cycle engines, such as the standard gasoline engine, deviate from the Beau de Rochas principles in many respects, based in large part upon practical considerations related to engine materials and the low-octane fuel used by the engine.
The six-stroke with external and internal combustion and double flow concept engine described in this monograph is designed to overcome many of the limitations inherent in the Otto cycle and bring the engine's operating cycle closer to Beau de Rochas' ideal efficiency conditions.
SATYA PRAKASH
[attachment=9077]
6 STROKE ENGINE
THE SIX-STROKE ENGINE WITH EXTERNAL AND INTERNAL COMBUSTION AND DOUBLE FLOW CONCEPT
ABSTRACT
One of the most difficult challenges in engine technology today is the urgent need to increase engine thermal efficiency. This paper presents the six-stroke engine with external and internal combustion and double flow concept in the development of high-efficiency engines for the 21st century.
The majority of I.C.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 and limited to 180 degrees of crankshaft angle.
According to its mechanical design, the six-stroke engine is similar to the I.C.engine. It differs due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: a combustion and an air heating chamber, both independent from the cylinder. Combustion, doesn’t occur within the cylinder but in the supplementary combustion chamber, doesn’t act immediately on the piston, and its duration is independent from the 180 degrees of crankshaft rotation that occurs during the expansion of the combustion gases.
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.
Key words: Six stroke engine, external and internal combustion, heating chamber
1. INTRODUCTION
One of the most difficult challenges in engine technology today is the urgent need
to increase engine thermal efficiency. Thermal management strategies and the choice of fuels will play crucial roles in the development of high-efficiency engines for the 21st century.
However, it was during the 19th century that the fundamental principles governing the efficiency of internal combustion engines were first posited. In 1862, Alphonse Beau de Rochas published his theory regarding the ideal operating cycle of the internal combustion engine.
He stated that the conditions necessary for maximum efficiency were:
(1) Maximum cylinder volume with minimum cooling surface;
(2) Maximum rapidity of expansion;
(3) Maximum pressure of the ignited charge and
(4) Maximum ratio of expansion.
Beau de Rochas' engine theory was first applied by Nikolaus Otto in 1876 to a four-stroke engine of Otto's own design. The four-stroke combustion cycle later became known as the "Otto cycle".
In the Otto cycle, the piston descends on the intake stroke, during which the inlet valve is held open. The valves in the cylinder head are usually of the poppet type. The fresh fuel/air charge is inducted into the cylinder by the partial vacuum created by the descent of the piston. The piston then ascends on the compression stroke with both valves closed and the charge is ignited by an electric spark as the end of the stroke is approached. The power stroke follows, with both valves still closed and gas pressure acting on the piston crown because of the expansion of the burned charge. The exhaust stroke then completes the cycle with the ascending piston forcing the spent products of combustion past the open exhaust valve. The cycle then repeats itself.
Each Otto cycle thereby requires four strokes of the piston- intake, compression, power and exhaust- and two revolutions of the crankshaft.
The disadvantage of the four-stroke cycle is that only half as many power strokes are 2 completed per revolution of the crankshaft as in the two-stroke cycle and only half as much power would be expected from an engine of given size at a given operating speed. The four-stroke cycle, however, provides more positive scavenging and charging of the cylinders with less loss of fresh charge to the exhaust than the two-stroke cycle. Modern Otto cycle engines, such as the standard gasoline engine, deviate from the Beau de Rochas principles in many respects, based in large part upon practical considerations related to engine materials and the low-octane fuel used by the engine.
The six-stroke with external and internal combustion and double flow concept engine described in this monograph is designed to overcome many of the limitations inherent in the Otto cycle and bring the engine's operating cycle closer to Beau de Rochas' ideal efficiency conditions.
