> 00000FT205121902 Pages: 2

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Third semester B.Tech examinations (S) September 2020

Course Code: FT205
Course Name: FUDAMENTALS OF HEAT AND MASS TRANSFER

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer any three full questions, each carries 10 marks. Marks
1 ஐ Derive the heat conduction equation in cylindrical coordinates. (7)

b) A temperature difference of 500°C is applied across a fire-clay brick having a (3)
10cm thick and a thermal conductivity of 1.0 W/mK. Find the heat transfer rate
per unit area.
2 9) Derive the General conduction equation in Cartesian Co-ordinates with all (5)
assumptions.
b) What is meant by critical radius of insulation? (5)
3 a) Using Buckingham 7 Theorem, show that Nusselt number is a function of (5)

Reynold’s number and Prandtl number.

b) What is forced convection and free convection? Give example for each. (5)

4 9) Explain the classification of boiling process. (6)

b) What are the differences between drop wise and film wise condensation? (4)
PART छ

Answer any three full questions, each carries 10 marks.

5 9) Derive the LMTD expression for parallel flow heat exchanger by indicating its (6)
assumptions involved.
b) Explain the various laws of radiation. (4)
6 9) A counter flow heat exchanger with a heat transfer area of 17.5 ന is to be used (5)
to cool oil (र्ण oil is 1.9kJ/kg.K )at 473 K .The oil flow rate is 2.77kg/s. Water
at 293 K is available as a cooling medium . It flows at a rate of 0.83 kg/s.
Calculate the exit temperatures of oil and water if the overall heat transfer
coefficient 19 300W/m°K.
b) What is LMTD and NTU? Discuss the advantage of NTU over the LMTD (5)

method?

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