Mechanical Engineering Exam > Mechanical Engineering Questions > A single cylinder compression ignition engine...
Start Learning for Free
A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine is
- a)10%
- b)35%
- c)50%
- d)70%
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A single cylinder compression ignition engine, operating on the air-st...
Thermal efficiency
Most Upvoted Answer
A single cylinder compression ignition engine, operating on the air-st...
Calculation of Thermal Efficiency of Diesel Engine
Given data:
Mean effective pressure = 1.0 MPa
Compression ratio = 21
Clearance volume = 5 x 10^-5 m^3
Heat added at constant pressure = 2.0 kJ
1. Calculation of Cut-off Ratio
Cut-off ratio is the ratio of the volume at the end of the combustion process to the volume at the beginning of the combustion process. It is calculated as follows:
Cut-off ratio = 1 / (compression ratio - 1)
Cut-off ratio = 1 / (21 - 1)
Cut-off ratio = 0.050
2. Calculation of Maximum Temperature
The maximum temperature in the cycle is reached at the end of the combustion process. It is calculated as follows:
Maximum temperature = (heat added at constant pressure) / (mass of air in the cylinder x specific heat at constant pressure)
Specific heat at constant pressure for air = 1.005 kJ/kg K
Mass of air in the cylinder = (clearance volume x atmospheric pressure) / (gas constant x absolute temperature)
Gas constant for air = 0.287 kJ/kg K
Atmospheric pressure = 101.3 kPa
Absolute temperature = 293 K
Mass of air in the cylinder = (5 x 10^-5 x 101.3) / (0.287 x 293)
Mass of air in the cylinder = 0.0069 kg
Maximum temperature = (2.0 x 10^3) / (0.0069 x 1.005)
Maximum temperature = 2899 K
3. Calculation of Thermal Efficiency
Thermal efficiency is the ratio of the net work output to the heat input. It is calculated as follows:
Thermal efficiency = 1 - (1 / (compression ratio)^((heat added at constant pressure) / (specific heat at constant pressure x mean effective pressure x cut-off ratio)))
Specific heat at constant pressure for air = 1.005 kJ/kg K
Thermal efficiency = 1 - (1 / (21)^((2.0 x 10^3) / (1.005 x 1 x 0.050)))
Thermal efficiency = 50%
Therefore, the thermal efficiency of the diesel engine is 50%.
Given data:
Mean effective pressure = 1.0 MPa
Compression ratio = 21
Clearance volume = 5 x 10^-5 m^3
Heat added at constant pressure = 2.0 kJ
1. Calculation of Cut-off Ratio
Cut-off ratio is the ratio of the volume at the end of the combustion process to the volume at the beginning of the combustion process. It is calculated as follows:
Cut-off ratio = 1 / (compression ratio - 1)
Cut-off ratio = 1 / (21 - 1)
Cut-off ratio = 0.050
2. Calculation of Maximum Temperature
The maximum temperature in the cycle is reached at the end of the combustion process. It is calculated as follows:
Maximum temperature = (heat added at constant pressure) / (mass of air in the cylinder x specific heat at constant pressure)
Specific heat at constant pressure for air = 1.005 kJ/kg K
Mass of air in the cylinder = (clearance volume x atmospheric pressure) / (gas constant x absolute temperature)
Gas constant for air = 0.287 kJ/kg K
Atmospheric pressure = 101.3 kPa
Absolute temperature = 293 K
Mass of air in the cylinder = (5 x 10^-5 x 101.3) / (0.287 x 293)
Mass of air in the cylinder = 0.0069 kg
Maximum temperature = (2.0 x 10^3) / (0.0069 x 1.005)
Maximum temperature = 2899 K
3. Calculation of Thermal Efficiency
Thermal efficiency is the ratio of the net work output to the heat input. It is calculated as follows:
Thermal efficiency = 1 - (1 / (compression ratio)^((heat added at constant pressure) / (specific heat at constant pressure x mean effective pressure x cut-off ratio)))
Specific heat at constant pressure for air = 1.005 kJ/kg K
Thermal efficiency = 1 - (1 / (21)^((2.0 x 10^3) / (1.005 x 1 x 0.050)))
Thermal efficiency = 50%
Therefore, the thermal efficiency of the diesel engine is 50%.
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
A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer?
Question Description
A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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 A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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 A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer?.
A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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 A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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 A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer?.
Solutions for A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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 A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer?, a detailed solution for A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A single cylinder compression ignition engine, operating on the air-standard diesel cycle, has a mean effective pressure of 1.0 MPa and a compression ratio of 21. The engine has a clearance volume of 5 x 10-5m3. The heat added at constant pressure is 2.0 kJ. The thermal efficiency of the engine isa)10%b)35%c)50%d)70%Correct 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