K L University 2008 B.E Industrial Production

Time 3hrs max marks 60
ans 1 ques. from all units
ans all units
Unit 1
1) Define the subsequent
a. Internal energy
b. Heat
c. Work
2) Describe joules experiment which conclude the internal energy of a gas depends only on its temperature, and not on its pressure and quantity
OR
1) State and expalin the 1st legal regulations of thermodynamics. elaborate its limitations.
2) Air at pressure of 50 bar and a quantity of 0.3 m^3 is expanded at constant pressure until the quantity is doubled. It is then expanded according to PV^(1.3)= constant until the quantity is o.8m^3. Caculate the work done in every process.
Unit 2
1) Derive the steady flow energy formula.
2) Air flows through a turbine in a quasi static adiabatic process from 3.5 bar and 823 K to one bar. The inlet velocity is 30 m/s and the outlet velocity is 300 m/s. compute the work output of the turbine per Kg of air .
Or
1) State the 2 statements of 2nd legal regulations of thermodynamics and prove their equivalency
2) A heat engine is supplied with 300 KJ per 2nd of heat at constant fixed temperature of (347+273)k with rejection of heat 280K, reported at the trades of
a. 210
b. 140
c. 70KJ/sec. comment on the nature of the cycle in every case, as followed by the heat engine.
Unit 3
1) Derive an expression for the change in entropy in a polytropic process involving an ideal gas in terms of pressure ratio, the polytropic exponent, the ratio of specific heats and specific heat at constant quantity.
2) Discuss briefly the concept of entropy. Starting from any point (T-S) sketch the subsequent operations for an ideal gas:
a. Iso thermal process
b. Constant quantity process
c. Constant enthalpy process
OR

1) Draw P-V diagram and T-S diagram for diesel cycle. Derive an expression for air standard efficiency of diesel cycle
2) A mass of one kg of air is taken through a Diesel cycle. Initially the air is at 180C and one bar. The compression ratio is 16, and the heat added is 1800KJ. compute the ideal cycle efficiency and mean effective pressure. presume R=0.287 KJ/kg0k, Cp=1.00KJ/kg0k and ¥= 1.4
Unit 4
1) Describe with a suitable sketch the 2 stroke cycle SI engine. How its indicator diagram differs from that of 4 stroke cycle engine.
2) What are the basic kinds of carburettors? Expalin with a neat sketch the working of any 1 of them.
OR
1) What are the different methods of measurement of brake horse power? Compare their merits and demerits.
2) A gas engine has piston diameter of 150mm, length of stroke 400mm and mean effective pressure 5.5 bar. The engine makes 120 explosions per minute. Determine the mechanical efficiency of the engine, if its BHP is 5KW
Unit 5
1) Describe the working of a single stage reciprocating air compressor
2) A single stage air compressor delivers 20kg of air minute after compressing it according to the legal regulations PV1.25= constant. obtain the power needed to drive the compressor, if the air is sucked at 270C and the pressure ratio is 20:3 .
OR
1) Derive the expression for the minimum work needed for a 2 stage reciprocating air compressor.
2) Find the percentage saving in work by compressing air in 2 stage from 1 bar to seven bar instead of in 1 stage. presume compression index 1.35 in both the cases and optimum pressure and complete inter cooling in 2 stage compressor.

Earning:   Approval pending.