Mechanical Engineering Exam > Mechanical Engineering Questions > The knocking tendency in compression ignition...
Start Learning for Free
The knocking tendency in compression ignition engines increase with
- a)increase of coolant water temperature.
- b)increase of temperature of inlet air.
- c)decrease of compression ratio
- d)increase of compression ratio
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
The knocking tendency in compression ignition engines increase witha)i...
In SI engine, knocking tendency increases with increase in compression ratio. In CI engine, knocking tendency decreases with increase in compression ratio and vice versa. If compression ratio is low in CI engine, there will not be enough temperature generation for ignition of the fuel air mixture.
Most Upvoted Answer
The knocking tendency in compression ignition engines increase witha)i...
Explanation:
Knocking tendency in compression ignition engines refers to the spontaneous combustion of fuel-air mixture before the intended ignition timing, which can cause engine damage. The following factors can affect knocking tendency:
Compression Ratio:
Compression ratio is the ratio between the volume of the combustion chamber when the piston is at the bottom of its stroke and the volume of the combustion chamber when the piston is at the top of its stroke. It has a direct impact on the pressure and temperature inside the combustion chamber during the compression stroke. Higher compression ratios tend to increase the temperature and pressure inside the chamber, which can increase the tendency of knocking.
Coolant Water Temperature:
Coolant water temperature affects the engine's cooling system, which can indirectly affect the knocking tendency. Higher coolant water temperature tends to reduce the cooling efficiency, which can increase the temperature inside the combustion chamber and increase the knocking tendency. However, this effect is much smaller compared to compression ratio.
Inlet Air Temperature:
Inlet air temperature affects the density of the air entering the engine, which can indirectly affect the knocking tendency. Higher inlet air temperature tends to reduce the air density, which can lower the compression pressure and reduce the tendency of knocking. However, this effect is much smaller compared to compression ratio.
Conclusion:
Among the given options, compression ratio has the most significant impact on the knocking tendency in compression ignition engines. Higher compression ratios tend to increase the temperature and pressure inside the combustion chamber, which can increase the tendency of knocking. Hence, option 'C' is the correct answer.
Knocking tendency in compression ignition engines refers to the spontaneous combustion of fuel-air mixture before the intended ignition timing, which can cause engine damage. The following factors can affect knocking tendency:
Compression Ratio:
Compression ratio is the ratio between the volume of the combustion chamber when the piston is at the bottom of its stroke and the volume of the combustion chamber when the piston is at the top of its stroke. It has a direct impact on the pressure and temperature inside the combustion chamber during the compression stroke. Higher compression ratios tend to increase the temperature and pressure inside the chamber, which can increase the tendency of knocking.
Coolant Water Temperature:
Coolant water temperature affects the engine's cooling system, which can indirectly affect the knocking tendency. Higher coolant water temperature tends to reduce the cooling efficiency, which can increase the temperature inside the combustion chamber and increase the knocking tendency. However, this effect is much smaller compared to compression ratio.
Inlet Air Temperature:
Inlet air temperature affects the density of the air entering the engine, which can indirectly affect the knocking tendency. Higher inlet air temperature tends to reduce the air density, which can lower the compression pressure and reduce the tendency of knocking. However, this effect is much smaller compared to compression ratio.
Conclusion:
Among the given options, compression ratio has the most significant impact on the knocking tendency in compression ignition engines. Higher compression ratios tend to increase the temperature and pressure inside the combustion chamber, which can increase the tendency of knocking. Hence, option 'C' is the correct answer.
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
|
Explore Courses for Mechanical Engineering exam
|
|
Similar Mechanical Engineering Doubts
Top Courses for Mechanical EngineeringView all
The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer?
Question Description
The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer?.
The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer?.
Solutions for The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering.
Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice The knocking tendency in compression ignition engines increase witha)increase of coolant water temperature.b)increase of temperature of inlet air.c)decrease of compression ratiod)increase of compression ratioCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
|
|
Explore Courses for Mechanical Engineering exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup