Thermal Engineering-1 Important Questions



Short Answer Questions

UNIT-I

  1. What is valve timing diagram why the inlet valve is opened before TDC and closed after BDC?
  2. What is combustion efficiency and combustion back duration?
  3. What is fluid friction in an engine?
  4.  What are the products formed during combustion process
  5.   What is an internal combustion engine?
  6. What is scavenging?
  7. What is meant by compression ratio? 
  8.  Define firing order
  9. What do you mean by SFC
  10. Define mean effective pressure.



UNIT-II 

  1. What is the normal combustion and abnormal combustion in SI engine?
  2. What is called flame front and flame velocity?
  3.  What is knocking in both SI and CI engines?
  4. What decides severity of knocking in both SI and CI Engines?
  5. What is pre ignition and optimum ignition timing?
  6. What is ignition delay period?
  7. Define suction induced swirl and combustion induced swirl?
  8.  What is mixture strength? How it influences the combustion?
  9.  What are anti knock agents? Main difference between working of anti knock agent in SI and CI ENGINES
  10. . What is a combustion chamber? What are the different combustion zones



UNIT-III

  1. Define brake power
  2. Define mechanical efficiency
  3. List the devices used to measure the cylinder pressure
  4. What is an indicated power
  5. What are the various losses of IC Engine?
  6. How do you determine heat losses explain with sankey diagram?
  7. Define clearance ratio.
  8. What is the function of air compressor?
  9. Define Isothermal work done
  10.  What is volumetric efficiency in case of compressor?
 
UNIT-IV
  1. What is volumetric efficiency in case of compressor?
  2. Define slip factor
  3. Define pressure coefficient.
  4. What is the difference between reciprocating and rotary compressors?  
  5. What is stalling?
  6. Draw p-v and T-S diagram of a MULTI stage reciprocating compressors?  
  7. What is the function of an intercooler in compressors?
  8. What are rotary compressors? 
  9. What is the difference between positive displacement and non positive  displacement   compressors?
  10.  What do you mean by Choking?
 
UNIT-V 
  1. 1. Define refrigeration
  2. Define (i) actual COP (ii) Theoretical COP (iii) Relative COP
  3. What is the difference between wet compression and dry compression?
  4. Write short notes on p-h chart.
  5. What is unit of refrigeration
  6. What is the function of capillary tube in vapour compression refrigeration
  7. What are the different components of vapour compression system
  8. what is the effect of subcooling
  9. Effect of superheating
  10. What is the function of Expansion valve?





ESSAY TYPE QUESTIONS

UNIT-I
  1. Give classification of IC Engines.  
  2. Distinguish between SI engines and CI engines?
  3. Sketch and explain the valve timing diagram of a 
  4. four stroke Otto cycle engine?
  5. In what respect two stroke engines differs from 4-stroke engine Discuss?
  6. Explain fuel injection system of an SI engine?
  7. What are the different lubrication systems available for IC engines?
  8. Discuss the importance of cooling system for an IC engines.
  9. Describe different cooling systems?
  10. List out the properties of fuel for  (i) SI engine (ii) CI engine.
  11. Explain lubrication system for IC engines?
  12. Explain cooling system for IC engines?





UNIT-II
  1. State and explain different combustion stages in SI engine?
  2. State and explain different combustion stages in CI engine?
  3. Explain knocking, properties and its effects in CI engine?
  4. Explain different types of combustion chambers in SI and CI engines?
  5. Explain the need for air motion and types?
  6. Factors influencing knocking in SI and CI engine?
  7. at are the requirements of fuel for a diesel engine?
  8. Differentiate   between   normal   combustion   and  abnormal   combustion phenomena incase of SI Engine
  9. What is the importance of variables like flame speed flame front in case of delay period.
  10. Plain knocking additives
  11. Discuss air flow movements in CI engines

UNIT-III
  1. Explain the Morse test to fins the frictional power.
  2. What is wilian’s line .how do you measure frictional power using this.
  3. Discuss different types of dynamometers.
  4. Write short notes on Exhaust gas analysis
  5. Derive volumetric efficiency of air compressor
  6. Classify compressors
  7. Explain Isothermal work done
  8. Derive equation for workdone of reciprocating air compressor  with T-S  and p-V diagrams
  9. Explain about intercooling
  10. Explain multistage compression

UNIT-IV
  1. State how the air compressors are classified?
  2. Explain the working of roots blower?
  3. the working of vane blower and also draw the actual p -v diagram of a compressor? 
  4. What is rotary compressor how are they classified?  
  5. Draw the velocity diagram of an axial flow compressor? 
  6. What do you mean by multistage compression? And state its advantages?
  7. Draw velocity diagrams of centrifugal compressors? 
  8. Compare between reciprocating and rotary compressors? 
  9. Compare between axial flow and centrifugal compressors? 
  10. Discuss of working centrifugal compressors? 


UNIT-V
  1. Describe a simple vapour compression cycle giving clearly its flow diagram
  2. Show the vapour compression cycle on T-S diagram when the vapour is dry saturated super heated, and is wet after compression 
  3. What are the factors that effect the performance of a vapour compression system and explain.
  4. What are desired properties of refrigerants 
  5. Explain with neat sketch the working of a vapour absorption system. 
  6. Compare between vapour compression and vapour absorption systems 
  7. Explain air refrigeration system 
  8. Explain reversed carnot cycle on T-S diagram, 
  9. What are the different components of vapour compression system and explain with neat  sketch 
  10. Classify refrigerants