Hello There, Guest! Register
Login with Facebook

Anna University April/May/June 2015 UG/PG Theory and Practical Exam Timetable
Second National Conference On Electrical Power And Energy Systems (EPES) - Kongunadu College of Engineering and Technology
Anna University Internal Assessment Schedule for May/June 2015 Exam
Anna University Question Papers : Nov Dec 2014 and Jan 2015 Question Papers | April May June 2014 Question Papers
Anna University Study Materials for all Departments

Register or Login to Submit Study Materials , Shoutbox and also to access Many Features !!

Don't Destroy your Notes - Sell your Lecture Notes on Vidyarthiplus (V+)

HEAT AND MASS TRANSFER 2012 Important Questions
#1
HEAT AND MASS TRANSFER 2012 IMPORTANT QUESTIONS
Common to
ME41:Heat and Mass Transfer
ME1251 Heat And Mass Transfer
080120015:Heat And Mass Transfer
113401:Heat and Mass Transfer

Unit I

1. Derive the general heat conduction equation in cylindrical coordinates.
2. Explain briefly the concept of critical thickness of insulation and state any two applications of the same
3. A composite wall consists. of 10 cm thick layer of building brick, k = 0.7 W/mK and 3 cm thick plaster, k = 0.5 W/mK. An insulating material of k = 0.08 W/mK is to be added to reduce the heat transfer through the wall by 40%. Find its thickness. [same model may be asked]
4 .Circumferential aluminium fins of rectangular profile (1.5cmwide and 1mm thick) are fitted on to a 90 mm engine cylinder with a pitch of 10 mm. The height of the cylinder is 120 mm. The cylinder base temperature before and after fitting the fins are 200°C and 150°C respectively. Take ambient at 30°C and h(average) =100 W/m K2 Estimate the heat dissipated from the finned and the unfinned surface areas of cylinder body. [same model may be asked]
5. Derive the general heat conduction equation for a hollow cylinder.

Unit II

1. Air at 400 K and 1 atm pressure flows at a speed of 1.5 m/s over a flat plate of 2 m long. The plate is maintained at a uniform temperature of 300 K. If the plate has a width of 0.5 m, estimate the heat transfer coefficient and the rate of heat transfer from the air stream to the plate. Also estimate the drag force acting on the plate[same model may be asked]
2. A steam pipe 10 cm OD runs horizontally in a room at 23° C. Take outside temperature of pipe as 165 ° C. Determine the heat loss per unit length of the pipe. Pipe surface temperature reduces to 80° C with 1.5 cm insulation. What is the reduction in heat loss? [same model may be asked]
3. Define Reynold’s, Nusselt and Prandtl numbers
4. A 6 – m long section of an 8 cm diameter horizontal hot water pipe passes through a large room in which the air and walls are at 20°C. The pipe surface is at 70°C and the emissivity of the pipe surface is 0.7. Find the rate of heat loss from the pipe by natural convection and radiation.

Unit III

1. Define effectiveness of a heat exchanger. Derive an expression for the effectiveness of a double pipe parallel flow heat exchanger. State the assumptions made.

2. A tube of 2 m length a nd 25 mm outer diame te r is to be used to condense saturated steam at 100°C while the tube surface is maintained at 92°C. Estimate the average heat transfer coefficie nt and the ra te of condensation of steam if the tube is kept horizonta l. The steam condenses on the outside of the tube. [same model may be asked]
3. Derive the LMTD for a parallel flow heat exchanger stating the assumptions
4. Consider laminar film condensation of a stationary vapour on a vertical flat plate of length L and width b. Derive an expression for the average heat transfer coefficient. State the assumptions made.
5. Discuss the various regimes of pool boiling heat transfer.

Unit IV

1. State and prove the following laws:
(1) Kirchoffs law of radiation
(2) Stefan - Boltzmann law

2. Liquid Helium at 4.2 K is stored in a dewar flask of inner diameter = 0.48 m and outer diameter = 0.5 m. The dewar flask can be treated as a spherical vessel. The outer surface of the inner vessel and the inner surface of the outer vessel are well polished and the emissivity of these surfaces is 0.05. The space between the two vessels is thoroughly evacuated. The inner surface of the dewar flask is at 4.2 K while the outer surface is at 300 K. Estimate the rate of heat transfer between the surfaces[same model may be asked]
3. Two large parallel plates of 1m×1m spaced 0.5m apart in a very large room whose walls are at 27°C. The plates are at 900°C and 400°C with emissivities 0.2 and 0.5 respectively. Find the net heat transfer to each plate and to the room. [same model may be asked]
4. Explain briefly the following:
(i) Specular and diffuse reflection
(ii) reflectivity and transmissivity

Unit V

1. Discuss briefly the following
(i) Fick’s law of diffusion
(ii) Equimolar counter diffusion
(iii) Evaporation process in the atmosphere
2. Air at 1.01 bar and 30°C flows past a tray full of water with a velocity of 2 m/s. The partial pressure of water vapour is 0.7 kPa and the saturation pressure is 3.17 kPa. The tray measures 40 cm along the flow direction and has a width of 20 cm. Calculate the evaporation rate of water if the temperature on the water surface is 25°C. Assume the following properties for air: density, ? 1.2 kg/m3, kinematic viscosity, ? = 15 × 10-6 m2/s and diffusivity, D = 0.145 m2/h[same model may be asked]
3. The temperature recorded by a thermometer whose bulb covered by a wet wick in dry air at atmospheric pressure is 22°C. Estimate the true air temperature. [same model may be asked]
4. Write short notes on the following:
(i) Analogy between heat and mass transfer
(ii) Evaporation process in the atmosphere.

For the student , by the student , to the student !!



Possibly Related Threads...
Thread Author Replies Views Last Post
  GE6351-Environmental science And Engineering Nov Dec 2014 Important Question kavi 4 1,744 04-12-2014, 02:58 PM
Last Post: Aravindhan Manogaran
  GE6251 Basic Civil And Mechanical Engg Nov Dec 2014 Important question kavi 0 521 03-12-2014, 06:47 PM
Last Post: kavi
  AT6032 Mechanics Of Machines Nov Dec 2014 Important Question kavi 0 617 03-12-2014, 04:56 PM
Last Post: kavi
  EC2312-Microprocessor and Microcontroller Nov Dec 2014 Important Question V+ Rajee 0 575 03-12-2014, 11:54 AM
Last Post: Rajee
  EC2304 Microprocessors And Microcontrollers Important Questions - Anand Edition Anandec 1 981 30-08-2014, 07:54 AM
Last Post: Srini
  080230069 Cloud computing Important Questions - All Units Srini 0 1,571 03-04-2014, 07:54 AM
Last Post: Srini
  ELECTRIC CIRCUITS AND ELECTRON DEVICES - Two Marks Important Questions Srini 4 5,833 25-01-2014, 09:56 AM
Last Post: pujimani
Thumbs Up ANNA UNIV- BASIC INDUSTRIAL BIOTECHNOLOGY- IMPORTANT 16 MARKS indiainspire 1 1,356 05-12-2013, 01:27 PM
Last Post: Rdx
  ANNA UNIV- BT2255 MICROBIOLOGY IMPORTANT 16 MARKS indiainspire 2 1,252 04-12-2013, 10:59 AM
Last Post: indiainspire
  BT2202 BIOORGANIC CHEMISTRY IMPORTANT QUESTIONS indiainspire 0 1,038 03-12-2013, 08:32 PM
Last Post: indiainspire
Reply


Subscribe


Recommend on Google

Latest Threads
-> M.Sc.(Software Engg.) Distance Education Dec 2013 Question Paper
Forum : Alagappa University
Last Post : Mathi Subhash
-> M.Sc.(IT) Distance Education Dec 2013 Question Paper
Forum : Alagappa University
Last Post : Mathi Subhash
-> 240 - Corporate Finance Question Paper Dec 2011
Forum : Annamalai University Question Paper
Last Post : Srini
-> Current Affairs 4th March 2015
Forum : Current affairs
Last Post : kavi
-> Current Affairs March 3rd 2015
Forum : Current affairs
Last Post : kavi
-> National Conference on “Corporate Social Responsibility As A Tool for Branding -...
Forum : Other Department / Other Events
Last Post : kavi
-> BAM 6L1 Vehicle Maintenance Lab Manual
Forum : Automobile Lab Manuals
Last Post : Srini
-> RATHINAM FEST - Rathinam Group of Institution
Forum : EEE Department Events
Last Post : kavi
-> Cebroid 2k15 - CSE & IT - Adhi College Of Engineering And Technology
Forum : CSE Department Events
Last Post : kavi
-> Operational Experiences of Chandrapur-Padghe HVDC bipole Project
Forum : Students IEEE Papers
Last Post : Aravindhan Manogaran
-> M.Pharm Quality Assurance Course Structure and Syllabus Type Version
Forum : Syllabus
Last Post : Aravindhan Manogaran
-> 251 - Banks and Stock Exchanges Question Paper Dec 2011
Forum : Annamalai University Question Paper
Last Post : Aravindhan Manogaran
-> 311 - Mobile and Wireless Networking Question Paper Dec 2011
Forum : Annamalai University Question Paper
Last Post : Aravindhan Manogaran
-> 310 - Telecom Network Management Question Paper Dec 2011
Forum : Annamalai University Question Paper
Last Post : Aravindhan Manogaran
-> 301 - Personnel Management Question Paper Dec 2011
Forum : Annamalai University Question Paper
Last Post : Aravindhan Manogaran