IC Engine |internal combustion Engine| Question and answers
IC Engine |internal combustion Engine| Question and answers
An internal combustion engine (I.C. engine) is a type of engine that generates mechanical power by burning fuel inside a combustion chamber. Here are brief explanations of different aspects of I.C. engines:
Purpose: The primary purpose of an I.C. engine is to convert the energy stored in fuel into mechanical work. This work is used to propel vehicles, generate electricity, or perform various mechanical tasks.
Combustion Process: Combustion in I.C. engines can occur in two types of engines: spark-ignition (S.I.) engines and compression-ignition (C.I.) engines. In S.I. engines, the combustion process begins with a spark from the spark plug. In C.I. engines, the self-ignition of fuel occurs due to high temperature and pressure.
Components: An I.C. engine consists of several key components, including a piston, cylinder, crankshaft, connecting rod, intake valve, exhaust valve, fuel injector or spark plug, and a combustion chamber. These components work together to facilitate the intake, compression, combustion, and exhaust processes.
Air-Standard Cycles: The performance analysis of I.C. engines often involves studying air-standard cycles, such as the Otto cycle and Diesel cycle. These theoretical models help analyze the thermodynamic processes occurring inside the engine, including intake, compression, combustion, and exhaust, to evaluate the engine’s efficiency and power output.
IC Engine |internal combustion Engine| Question and answers
Testing and Performance: I.C. engines are tested to measure their performance and characteristics. Engine performance testing involves measuring parameters like power output, torque, fuel consumption, and emissions. Dynamometers are commonly used to load the engine and measure its output. Brake Mean Effective Pressure (BMEP) is a key indicator of engine performance.
Lubrication: Engine lubrication is crucial to reduce friction and wear between moving parts. Lubricating oil is circulated within the engine to provide a thin film of oil that prevents direct metal-to-metal contact and aids in heat dissipation.
Types of Fuel: I.C. engines commonly use gasoline (petrol) or diesel as fuel. Gasoline engines rely on spark ignition, while diesel engines achieve combustion through compression ignition. Alternative fuels like natural gas, ethanol, and hydrogen are also used in some engines.
Efficiency and Emissions: Improving the efficiency of I.C. engines is an ongoing area of research and development. Higher efficiency means extracting more useful work from the fuel and reducing waste. Efforts are also made to minimize emissions of pollutants like nitrogen oxides (NOx), carbon monoxide (CO), and particulate matter.
Overall, I.C. engines have played a significant role in various industries and transportation sectors, and ongoing advancements continue to enhance their performance, efficiency, and environmental impact.
IC engine:
a) What is the role of a piston in an I.C. engine?
Answer: To transfer the force of combustion to the crankshaft.
b) What is the function of an intake valve in an I.C. engine?
Answer: “To let the mixture of air and fuel get inside the part where it burns and produces power.
c) Which component of the engine is responsible for changing back-and-forth motion into circular motion?”
Answer: Crankshaft.
d) What is the purpose of engine lubrication?
Answer: To reduce friction and wear between moving parts.
e) Name one type of I.C. engine other than spark-ignition and compression-ignition engines.
Answer: Rotary engine.
f) What does “I.C.” stand for in I.C. Engines?
Answer: Internal Combustion
h) Name one major difference between an I.C. engine and an external combustion engine.
Answer: Combustion occurs inside the engine (I.C.) vs. outside the engine (external)
i) What is the primary purpose of an I.C. engine?
Answer: To convert fuel energy into mechanical work
j) Which fuel is commonly used in I.C. engines?
Answer: Gasoline (petrol) or diesel
k) Name one component of an I.C. engine that aids in the combustion process.
Answer: Spark plug (in S.I. engines) or fuel injector (in C.I. engines)
Air-standard Otto & Diesel Cycles:
IC Engine |internal combustion Engine| Question and answers
a) What are the two main types of air-standard cycles used in I.C. engines?
Answer: Otto cycle and Diesel cycle
b) Which cycle is used in spark-ignition (S.I.) engines?
Answer: Otto cycle
c) Which cycle is used in compression-ignition (C.I.) engines?
Answer: Diesel cycle
d) State one difference between the Otto cycle and the Diesel cycle.
Answer: Otto cycle relies on spark ignition, while Diesel cycle relies on self-ignition due to high pressure and temperature.
e) What is the main purpose of an air-standard cycle analysis?
Answer: To analyze and evaluate the performance of I.C. engines theoretically.
h) What is the compression ratio of an Otto cycle engine?
Answer: The ratio of the cylinder volume at the beginning and end of compression.
i) How is the combustion process initiated in an Otto cycle engine?
Answer: By a spark from the spark plug.
j) What is the main difference between the Otto and Diesel cycles in terms of heat addition?
Answer: Otto cycle has constant volume heat addition, while Diesel cycle has constant pressure heat addition.
k) What is the purpose of the expansion stroke in the Diesel cycle?
Answer: To extract work from the high-pressure gases.
l) Which cycle is more thermodynamically efficient: Otto or Diesel?
Answer: Diesel cycle is generally more thermodynamically efficient.
Combustion in S.I. & C.I. Engines:
a) What does “S.I.” stand for in S.I. engines?
Answer: Spark Ignition
b) What does “C.I.” stand for in C.I. engines?
Answer: Compression Ignition
c) In which type of engine does the combustion process begin with a spark?
Answer: Spark Ignition (S.I.) engines
d) In which type of engine does the combustion process begin with the self-ignition of fuel due to high temperature and pressure?
Answer: Compression Ignition (C.I.) engines
e) What is the common byproduct of the combustion process in both S.I. and C.I. engines?
Answer: Carbon dioxide (CO2) and water vapor (H2O)
f) Name one pollutant produced during combustion in S.I. and C.I. engines.
Answer: Nitrogen oxides (NOx).
g) What is the function of a catalytic converter in S.I. engines?
Answer: To reduce harmful emissions by promoting chemical reactions.
h) What is the ignition temperature of diesel fuel?
Answer: Lower than gasoline; around 200-250 degrees Celsius.
i) How is the air-fuel mixture ignited in a spark-ignition engine?
Answer: By a spark generated by the spark plug.
j) Which type of engine is more prone to knocking: S.I. or C.I.?
Answer: S.I. engines are more prone to knocking.
Performance & Testing of Internal Combustion Engines:
IC Engine |internal combustion Engine| Question and answers
a) What is the measure of an engine’s power output?
Answer: Horsepower (HP) or kilowatts (kW)
b) What does BMEP stand for in engine performance testing?
Answer: Brake Mean Effective Pressure
c) What is the purpose of a dynamometer in engine testing?
Answer: To measure the power output and torque of an engine.
d) What is the purpose of a dynamometer in engine testing?
Answer: To measure the power output and torque of an engine.
e) What is the purpose of a dynamometer in engine testing?
Answer: To measure an engine’s power output and torque.
f) What is indicated power in engine performance testing?
Answer: The power developed within the engine cylinder, measured by an indicator.
g) What is brake power in engine performance testing?
Answer: The power available at the crankshaft after accounting for losses.
h) Name one method used to measure fuel efficiency in engine testing.
Answer: Brake-specific fuel consumption (BSFC).
i) What is the purpose of a pressure transducer in engine testing?
Answer: To measure pressure changes within the combustion chamber.
For more data please visit: Mechanicle vibrations
For Telangana Latest notifications please visit: TSPSC