Advanced Heat Transfer-II Question Paper 2011 for BPUT M.Tech Mechanical Engineering (Thermal or Heat Power engineering) 2nd Semester is given below. These questions were asked from Advanced Heat Transfer-2 subject. Mahesh Rathode is Heat Transfer book (Laxmi Publication) is the Best book for Advanced Heat Transfer-II subject.
Second Semester Examination 2011
ADVANCED HEAT TRANSFER-II Question Paper 2011
(CONVECTIVE HEAT & MASS TRANFER)
Time: 3 Hours
Max. Marks: 70
Answer Question No.1 which is compulsory and any five from the rest.
The figures in the right-hand margin indicate marks.
1. Answer the following questions: 2×10
(a) What do you understand by turbulence modeling?
(b) How does Scale analysis differ from Dimensional analysis?
(c) Give the significance of Reynolds-Colburn analogy?
(d) Whether the solution of natural convection is more complicated than the solution of forced convection or not? Justify your answer.
(e) What is LMTD and write down the expression for it.
(f) What is the effectiveness of heat exchanger, write down the expression for effectiveness for parallel and counter flow exchanger?
(g) Explain how boiling is differ from evaporation.
(h) Define Prandtl number with its physical significance.
(i) What is Shearwood number, and what is its physical significance
(j) Write down the mass continuity equation for incompressible flow in cylindrical coordinate system.
2. Derive the generalized energy equation in two-dimensional Cartesian coordinate system. Simplify the same for incompressible, laminar flow and fluid of constant properties, neglecting heat generation.
3. Prove that the Nusselt number for fully developed flow in a-circular tube subjected to constant surface temperature remains constant.
4. Prove that Nu= f (Gr, Pr) for a natural convection. Differentiate between the dimensional analysis and scale analysis.
5. A counter flow concentric tube heat exchanger is used to cool the lubricating oil for a large industrial gas turbine engine. The flow rate of cooling water through the inner tube (Di = 25mm) is 0.2 Kg/s, while the flow rate of oil through the outer annulus (Do = 45mm) is 0.1 Kg/s . the oil and water enter at temperature of 100 and 30 degree celcius respectively. How long must be the tube is made if the outlet temperature of the oil is to be 60 degree celcius.
6. Hot exhaust gases, which enter a finned tube, cross-fow heat exchanger at 300 degee Celcius and leaves at 100 degree celcius, are used to heat pressurized water at a flow rate of 1 kg/s from 35 to 125 degree C. The exhaust specific heat is approximately 2.6 kj/kg and the overall heat transfer coefficient based on the gas-side surface area is Uh=100W/m2K. Determine the required gas side surface area Ah using the NTU method.
7. Explain the boiling curve and the regimes.
8 . Derive the vorticity transport equation and state its limitation and advantage compared to that of primitive variable method.