Saturday, 2 April 2011

what is an IC Engine.....???

                                  The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine the expansion of the high-temperature and -pressure gases produced by combustion applies direct force to some component of the engine, such as pistons, turbine blades, or a nozzle. This force moves the component over a distance, generating useful mechanical energy.

                            The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.

The Concept IC Engine:
 
                                            The second really innovative engine design described in these pages, is the Concept IC Engine , which utilises a revolutionary new design , to completely transform the conventional IC engine . The great advantage of this design is that existing IC engines can be modified to run as Concept IC engines at minimum cost while at the same time increasing efficiency by as much as 200% and also reducing fuel emissions to zero. 
 
                     This may sound far fetched but as you will see , if you continue to read these pages , a detailed and well documented rationale is given as to why this engine can and will work. In fact anyone who can provide a logical and verifiable refutation of the Concept IC engine shall receive from me a most abject and humble letter of apology. Studies have shown , and this may easily be verified from The Colorado State University Engine Web Site , a link to which is provided , that IC engines lose 42% of their energy to exhaust and 28% of their energy to the cooling system. With more than 500 million cars world wide (not counting buses , trains , construction and military transport ) and with this number constantly increasing there is an urgent need for better , cleaner , more efficient engines. The Concept IC engine provides a low cost and highly effective solution to solving all these problems. 
 
 Efficiency of the IC engine:
 
                                             IC engines lose 42% of their energy to exhaust and 28% of their energy to the cooling system. Therefore the true explanation for the poor performance of the engine would seem to lie in inefficient use of energy and loss of energy through heat transfer. The loss incurred through inefficient use of energy is easily understood , compressed fuel and air is ignited and is then used to propel the piston down the cylinder with explosive force for a distance of just a few inches after which all further energy developed by the fuel is lost and in fact becomes a liability since the piston has to reverse direction , a process which is inhibited by the pressure of trapped gases on the piston head. The reason that energy loss to heat transfer has been tolerated , and even welcomed by engineers , is a little more involved and will be referred to later on in the article. Notwithstanding the improvements made to the RI engine we have to ask ourselves , and this is the million dollar question , is this really the limit of performance of the reciprocating internal combustion engine, does this mark the end of the road for this more than 200 year old concept , some entrepreneurs seem to think not , they have come up with the idea of a concept IC engine. 
 
 

 
Power stroke in an IC engine examined:

                       If we examine in detail , the power stroke in a four stroke cycle of the RI engine the concept of a recoilless engine , and why it can work , becomes clearer., We find that ignition is intitiated at a minimum of 20 - 30 degrees before TDC , the piston then continues up the cylinder reaches TDC and then reverses direction traveling down the cylinder , valve lead or the opening of the exhaust valve in order to relieve pressure on the piston head has to be initiated in the same stroke at a minimum of 50 degrees before BDC , if this were not the case the piston head would be damaged or cracked due to the conflicting stresses. Thus taking the full stroke to be 180 degrees , we find that power is available for roughly 130 degrees. In a concept IC engine , the exhaust valve would be fully opened after ignition and conventional power (i.e with valves closed ) would be available for 80 to 90 degrees as compared to the 130 degrees of the conventional engine and recoilless energy would account for completion of the remaining part of the stroke, the difference to final power output would therefore be negligible.  
 

Specification of an IC Engine
                        The internal combustion engine (or ICE) is quite different from external combustion engines, such as steam or Stirling engines, in which the energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in some kind of boiler.

                                 A large number of different designs for ICEs have been developed and built, with a variety of different strengths and weaknesses. Powered by an energy-dense fuel (which is very frequently gasoline, a liquid derived from fossil fuels). While there have been and still are many stationary applications, the real strength of internal combustion engines is in mobile applications and they dominate as a power supply for cars, aircraft, and   boats, from the smallest to the largest.

History:

                                      At one time, the word, "Engine" (from Latin, via Old French, ingenium, "ability") meant any piece of machinery—a sense that persists in expressions such as siege engine. A "motor" (from Latin motor, "mover") is any machine that produces mechanical power. Traditionally, electric motors are not referred to as "Engines"; however, combustion engines are often referred to as "motors." (An electric engine refers to a locomotive operated by electricity.)

Engines can be classified in many different ways: By the engine cycle used, the layout of the engine, source of energy, the use of the engine, or by the cooling system employed.


Operation:

Four-stroke cycle (or Otto cycle)
1. Intake
2. Compression
3. Power
4. Exhaust

As their name implies, operation of four stroke internal combustion engines have four basic steps that repeat with every two revolutions of the engine:

   1. Intake
          * Combustible mixtures are emplaced in the combustion chamber
   2. Compression
          * The mixtures are placed under pressure
   3. Combustion (Power)
          * The mixture is burnt, almost invariably a deflagration, although a few systems involve detonation. The hot mixture is expanded, pressing on and moving parts of the engine and performing useful work.
   4. Exhaust
          * The cooled combustion products are exhausted into the atmosphere

Many engines overlap these steps in time; jet engines do all steps simultaneously at different parts of the engines.

More...

1. What happens when you start a car ....!!


video