Looking for PTU B.Tech old question papers ? You can see here B.Tech HEAT TRANSFER 2014 question paper. Collect the question paper contents provided below.
Punjab Technical University
B.Tech 2014
HEAT TRANSFER
PAPER CODE :BTME-602
PAPER ID: [A-2362]
Time Allowed: 3 Hours Max. Marks: 60
Section A
Q1.
a) What is the effect of temperature on thermal conductivity of solids, liquids and gases? Justify your answer.
b) What is meant by critical thickness of insulation?
c) Define Kirchoff`s law.
d) Write down Fourier, Laplace & Poisson equations of heat transfer.
e) Define thermal diffusivity. What is its physical significance?
f) Define Shape factor.
g) What is critical Reynolds number? State its approximate values for flow over flat plate and a circular tube.
h) Define effectiveness and NTU of a heat exchanger.
i) Define hydrodynamic boundary layer. Which non dimensional number governs the relative magnitude of hydrodynamic and thermal boundary layers?
j) State Buckingham pi theorem. What are repeating variables, how they are selected?
Section B [Marks: 5 each]
Q2. Explain different types of condensation.
Q3. Derive three dimensional heat conduction equation in cylindrical coordinates. Reduce the equation to one dimensional, steady state without internal heat generation.
Q4. Define emissive power and intensity of radiation. Using the concept of solid angle find relation between the two.
Q5. Prove by dimensional analysis for natural convection, Nu= F (Gr, Pr).
Q6. What is the criterion for selection of heat exchangers?
Section C [Marks: 10 each]
Q7. Derive relation of temperature distribution and heat transfer for thin fin insulated at the tip.
Q8. Air at 200C and at atmospheric pressure flows at a velocity of 5.5 m/s past a flat plate with a sharp leading edge. The entire plate surface is maintained at a temperature of 700C. Assuming that the transition occurs at a critical Reynolds No. of 5x105, find the distance from the leading edge at which the boundary layer changes from laminar to turbulent. At the location, calculate the following:
i. Thickness of hydrodynamic boundary layer.
ii. Thickness of thermal boundary layer.
iii. Local & average convective heat transfer coefficients.
iv. Heat transfer rate from both sides per unit width of plate.
Q9. Three hollow thin walled cylinders having diameters 10cm, 20cm, 30 cm are arranged concentrically. The temperatures of the innermost & outermost cylindrical surfaces are 150K & 350K respectively. Assuming vacuum between annular spaces, find the steady state temperature attained by the cylindrical surface having diameter of 20cm. Take e1= e2= e3=0.04.
Punjab Technical University
B.Tech 2014
HEAT TRANSFER
PAPER CODE :BTME-602
PAPER ID: [A-2362]
Time Allowed: 3 Hours Max. Marks: 60
Section A
Q1.
a) What is the effect of temperature on thermal conductivity of solids, liquids and gases? Justify your answer.
b) What is meant by critical thickness of insulation?
c) Define Kirchoff`s law.
d) Write down Fourier, Laplace & Poisson equations of heat transfer.
e) Define thermal diffusivity. What is its physical significance?
f) Define Shape factor.
g) What is critical Reynolds number? State its approximate values for flow over flat plate and a circular tube.
h) Define effectiveness and NTU of a heat exchanger.
i) Define hydrodynamic boundary layer. Which non dimensional number governs the relative magnitude of hydrodynamic and thermal boundary layers?
j) State Buckingham pi theorem. What are repeating variables, how they are selected?
Section B [Marks: 5 each]
Q2. Explain different types of condensation.
Q3. Derive three dimensional heat conduction equation in cylindrical coordinates. Reduce the equation to one dimensional, steady state without internal heat generation.
Q4. Define emissive power and intensity of radiation. Using the concept of solid angle find relation between the two.
Q5. Prove by dimensional analysis for natural convection, Nu= F (Gr, Pr).
Q6. What is the criterion for selection of heat exchangers?
Section C [Marks: 10 each]
Q7. Derive relation of temperature distribution and heat transfer for thin fin insulated at the tip.
Q8. Air at 200C and at atmospheric pressure flows at a velocity of 5.5 m/s past a flat plate with a sharp leading edge. The entire plate surface is maintained at a temperature of 700C. Assuming that the transition occurs at a critical Reynolds No. of 5x105, find the distance from the leading edge at which the boundary layer changes from laminar to turbulent. At the location, calculate the following:
i. Thickness of hydrodynamic boundary layer.
ii. Thickness of thermal boundary layer.
iii. Local & average convective heat transfer coefficients.
iv. Heat transfer rate from both sides per unit width of plate.
Q9. Three hollow thin walled cylinders having diameters 10cm, 20cm, 30 cm are arranged concentrically. The temperatures of the innermost & outermost cylindrical surfaces are 150K & 350K respectively. Assuming vacuum between annular spaces, find the steady state temperature attained by the cylindrical surface having diameter of 20cm. Take e1= e2= e3=0.04.
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