Factors Affecting Detonation In IC Engine

Factors Affecting Detonation In Internal Combustion Engine:

In an internal combustion engine cylinder sometime sudden and violent knocks are experienced, this is known as "Detonation". This knock is set up by a high pressure wave giving loud pulsating noise as it strikes against cylinder walls, cylinder head and piston.

Following are the main factors, which affects detonation:-

01) The fuel used in internal combustion engine will considerably effects on the chances of detonation. Alcohol and benzol do not cause detonation but it can not be use due its low calorific value and other objections to use as fuel. Again alcohol cannot blend with petrol in the presence of water.

02) The detonation is also promoted by increase in compression ratio. The compression ratio at which detonation just occurs is known as the Highest Useful Compression Ratio. Higher the compression ratio higher the chances of detonation and lower the output.

03) If the carbon deposits are in the cylinder and used excessive sparking temperature, the detonation will increased rapidly.

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.) What is the direction of tangential acceleration ?

Ans:The direction of tangential acceleration may be same or opposite to that of angular velocity.

2.)Why excess air is required to burn a fuel completely ?

Ans: Excess air is required to ensure adequate mixing of fuel and air, avoid smoke, minimize slagging in coal burning, and to ensure maximum steam output.

3.)Which type of plant will you recommend for remote location if power is required in six to twelve months time ?

Ans: Diesel engine power plant.

4.)What do you understand by forced convection ?

Ans: When convection heat transfer occurs between a solid body and a fluid and where circulation of fluid is caused and controlled by some mechanical.

Thermodynamic Processes

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)What happens if gasoline is used in a Diesel engine?Diesel engine will work ?

Ans.:No, It will not work,as the Compression ratio of Petrol engine is 6 to 10 & that of Diesel engine is 15 to 22. Thus on such high compression, gasoline gets highly compressed & it may blast.

2.)Why different types of sound are produced in different bikes though they say run on SI engine?

Ans:Engine specifications are different in different manufactures like as Bore Diameter(CC), Ignition timing.Also the exhaust passage take more responsible for sound.

3.)1 hp how much watt?

Ans: 746.2Watt

4.)Explain Bicycle rear wheel Sprocket working?

Ans:Rear wheel sprocket works under the principle of ratchet and pawl.

Spark Plug

 

A spark plug (sometimes in British English a sparking plug, colloquially a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto. The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded. The central electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the central electrode and usually one or more protuberances or structures attached to the inner end of the threaded shell and designated the "side", "earth", or "ground" electrode(s).
Spark plugs may also be used for other purposes; in Saab Direct Ignition when they are not firing, spark plugs are used to measure ionization in the cylinders - this ionic current measurement is used to replace the ordinary cam phase sensor, knock sensor and misfire measurement function.[citation needed] Spark plugs may also be used in other applications such as furnaces wherein a combustible fuel/air mixture must be ignited. In this case, they are sometimes referred to as flame igniters.