Thermal Engineering 1 Diploma 3rd Semester Important questions

Thermal Engineering 1 Diploma 3rd Semester Important questions

Unit 2  

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We have added Thermal Engineering 1 Important Questions, Thermal Engineering 1 Diploma 3rd Semester Important questions for N scheme. You can download the Thermal Engineering 1 Diploma 3rd Semester Important questions pdf 

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Department of Mechanical Engineering

Subject Code: 4020340                                                                      Subject: Thermal Engineering 1

Note:

1. The following questions are collected from board exam question papers (from april 2014) of the previous scheme (L and M )
2. The highlighted questions are asked more than two times in Board Exam
3. Join Diploma Exam Corner Study Material WhatsApp and Telegram group for Mechanical Department Study materials

Unit 2, THERMODYNAMIC AIR CYCLES AND HEAT TRANSFER

14 Marks

1. In an otto cycle, the pressure and temperature of the air at the beginning of compression are 97 kN/m² and 50⁰C respectively. The ratio of compression is 5:1. The heat supplied during the cycle is 970 kJ/kg of the working fluid. Determine (i) maximum temperature of the cycle (ii) the thermal efficiency of the cycle and (iii) the work done during the cycle per kg of working fluid assume γ = 1.4 and Cv = 0.717 kJ/kgK
2. Find the power output of a diesel engine working on a standard diesel cycle with a compression ratio of 16 and an air flow rate of 0.25 kg/s. the initial condition of air is at 1 bar pressure absolute and 27^o C temperature. Head added per cycle is 2500 kJ/kg. Assume Cp=1.0 kJ/kgK Cv = 0.714 kJ/kgK
3. An engine working on otto cycle has a compression ratio of 7. The temperature of air at the start of compression stroke is 40^o the maximum temperature is 1250⁰C. Determine the work done per cycle and the efficiency of the cycle. Assume Cp = 1.005 kJ/kgK and Cv=0.717 kJ/kgK
4. A Carnot cycle works between the temperatures limits 627⁰C and 27⁰C and pressure limits of 60 bar and 1 bar. Determine (i) Pressure and temperature at all points of the cycle (ii) Workdone per kg of air (iii) thermal efficiency Assume γ = 1.4
5. In an ideal Diesel Cycle, the compression ratio is 15:1 and the expansion ratio is 7:5:1. The pressure and temperature at the beginning of compression are 98 k/Nm²  and 44⁰C respectively and the pressure at the end of expansion is 258.6 kN/m². Determine (i) the maximum temperature of the cycle and (ii) thermal efficiency of the cycle Take γ = 1.4
6. Mention the applications of steady flow energy equation
7. Determine the air standard efficiency of an engine working on otto cycle. If the pressure at the beginning and the end of compression are 103.5 kN/m² and 827.5 kN/m² Take γ = 1.4

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8. Explain the working of a parallel flow heat exchanger with a line sketch

9. Determine the air standard efficiency of a diesel cycle engine. If the cut off is 6% of the stroke and the clearance is 1/13^th of the stroke. Take γ = 1.4

10. Air expands from 4 bar to 1 bar in a nozzle. The initial velocity is 100 m/s and the temperature is 160^o Determine the final velocity Cp = 1.005 kJ/kgK

11. Explain the working of a counter flow heat exchanger with a line sketch.

12. Derive the formula for air standard efficiency of carnot cycle. Draw its P-V and T-S diagrams

13. A carnot engine working between the temperature limits of 650K and 310K delivers 150J of work. Find (a) thermal efficiency and (B) Heat added

14. Derive steady flow energy equation. Draw the steady flow system and state assumptions made.

15. Derive the formula for thermal efficiency of otto cycle. Draw its P-V Diagram

16. In an otto cycle operation, the compression ratio is changed from 4.5 to 8.5. determine the increase in air standard efficiency of the cycle. Take γ=1.4

17. Derive the formula for energy equation in a non flow system (4 marks)

18. Derive the formula for heat conducted through three composite plane wall of thickness t₁,t₂ and t₃ and thermal conductivity K₁, K₂ and K₃ respectively

19. An otto cycle has a compression ratio of 7 and works between the temperature limits 300K and 1430K. determine the maximum power developed when the working fluid is used at the rate of 0.4 kg/min. also determine the temperature at the end of compression If γ=1.4 and Cv = 0.718 kJ/kgK

20. A perfect heat engine working on carnot cycle convers 1/6^th of the heat input into work. When the temperature of the sink is reduced by 62^oC, the efficiency is doubled. Determine the temperature of the sink and source.

Thermal Engineering – 1 3 Marks Questions and answers
Unit 1	Click here
Unit 2 Part 1	Click here
Unit 2 Part 2	Click here
Unit 3	Click here
Unit 4	Click here
Unit 5	Click here