theoretical & derivation based questions and...

http://ajourneywithtime.weebly.com/ats.html By M. K. PODDAR, A.P, IIT GZB.

Theoretical & Derivation based Questions and Answer

Unit 01

1. Derive the condition for exact differentials.

Solution:


2*. Derive the Maxwell relations and explain their importance in thermodynamics.

Solution:


3. Starting from 1st Maxwell relation and using cyclic relation, derive remaining three

relations.

Solution:


4*. Derive the equation for Clausius – Clapeyron equation for evaporation of liquids.

Answer: Refers class notes

5*. Explain the following

(a) Coefficient of volume expansion

(b) Joule Thomson coefficient

(c) Isothermal compressibility.


6*. Explain the following

a) What are primary fuels and secondary fuels? List some important primary and secondary

fuels.

b) What do you mean by stoichiometric air-fueln(A/F) ratio?

c) Enthalpy of formation (ΔHf)

d) Heating values of fuel

e) Adiabatic Flame Temperature


For Numericals

Refers class notes and solve previous year numerical questions

Unit 2:

7. Classify the boiler briefly.


8*. Give the name of various mountings and accessories of boiler and also explain its functions.


9. What are the elements of steam condensing plant? Explain its function briefly. Answer: Refers class notes

10. State the comparison between jet and surface condenser. Answer: Refers class notes & Books

11. Explain briefly the effects of air leakage in a steam condenser?


12*. Explains briefly any one jet condenser with neat sketch. Answer: Refers class notes & Books

13*. With neat sketch, explain the working of evaporative condenser. Answer: Refers class notes & Books

For Numericals


Unit 3

14. Explain the various operation of a vapour carnot cycle. Also represent it on a T-s

and p-v diagrams.



15*. Describe the different operation of Rankine cycle. Derive also the expression for its

efficiency. What are the effects of pressure and temperature on rankine cycle?


16*. Explain the working with the help of neat diagram & also derive an expression for

its thermal efficiency. Also explain its advantages and disadvantages

(a) Reheat cycle

(b) Regenerative cycle.

(c) Binary vapour cycle.

(d) Modified Rnakine cycle


17. Explain with neat sketch the construction and working of steam engine.


18*. Explain clearly what do you mean by ‘saturation curve’ and missing quantity.

Suggest the ways by which missing quantity can be reduced.


For Numericals


Unit 04

19*. Derive the expression for mass flow rate per unit area of steam in a nozzle. Also

give the condition for maximum discharge.


20. Define critical pressure ratio for the nozzle of steam turbine. Obtain analytically its value

in term of index of expansion (n).


21*. What do you mean by a supersaturated flow? Explain with the help of h-s diagram.

Answer: Refers book ‘Thermal engineering’ by Er. R.K Rajput, Ch-18, page no. 444

22. What is the nozzle efficiency?

Answer: it is defined as the ratio of the actual enthalpy drop to the isentropic enthalpy drop

between the same pressures.

23*. Make a comparison between impulse turbine and reaction turbine.


24. Explain the working of a single stage impulse steam turbine. Sketch the pressure

and velocity variations along the axis of the turbine.

Answer:


25. Draw the velocity vector diagram of a single stage impulse turbine and set up

expression for the axial thrust, tangential force, work done and diagram efficiency.


26*. Why compounding is done in steam turbine? Discuss the various methods of compounding

steam turbine. Also discuss its salient features.


27*. Derive the condition for maximum efficiency of single stage impulse turbine and

write its expression. Also plot efficiency vs blade speed ratio.


28**. Explain various methods used for governing of steam turbines.

Answer:


For Numericals


For steam turbine problem prefer 1st manual approach it time permits them go for 2

nd method

graphical approach.

Unit 5 29. What is the difference between gas turbine Vs Steam turbine?


30*. Derive an expression for the air standard thermal efficiency of the Brayton cycle in

terms of the compression ratio and adiabatic index.

Solution:


31*. Prove that the optimal pressure ratio for maximum specific output for a gas

turbine plant is given by rp= (T3/T1)γ/2(γ-1)

, where T3 and T1 is the maximum and

minimum temperate. or

For a constant pressure closed cycle gas turbine, derive the mathematical Expression of

optimum pressure ratio for maximum cycle thermal efficiency

Solution: Up to work done do same as Q. no. 30, rearrange workdone in term of pressure ratio

& differentiat it w.r . to pressure ratio & equate it to zero. For detail Refers class notes

32*. Discuss the influence of reheating, regeneration and intercooling on the

performance of a gas turbine cycle.


33**. Explain with a neat sketch the working of

(a) Turbojet engine (b) Turbo-prop engine (c) Rocket Engine

Also discuss its application & advatages

For Numericals


Solve both numerical of closed cycle gas turbine and open cycle gas turbine

theoretical & derivation based questions and...

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