FACULTY OF MECHANICAL ENGINEERING “In the name of Allah, The Most Beneficent, The Most Merciful”Lab 02: Heat ConvectionBMM 3531 Engineering Thermodynamics Lab Lab Instructors Muhamad Zuhairi Sulaiman Idris Bin Mat Sahat Prof. Dr. K. V. Sharma Amir Bin Abdul RazakMohd Razali Bin Hanipah Lab Location Thermodynamics Laboratory, FKMLab Outcomes By the end of the semester, student should be able to: 1.Define and explain the boundary layer concept 2.Distinguish between free and forced convective mechanisms and the non- dimensional numbers/parameters representing them. 3.Identify equations applicable for the estimation of free/force convective heat transfer coefficient for different geometries and flow conditions (laminar and turbulent). 4.Apply the concept and theoretical analysis of fins (for rectangular cross-section) 5.Distinguish between the mechanism of heat flow from a single fin and a fin array6.Evaluate the heat transfer coefficients for different fin arrays under free and forced convection. Group Members Student ID Section 100 Due Date: Delivered Date:
“In the name of Allah, The Most Beneficent, The Most Merciful”
Lab 02: Heat Convection
BMM 3531 Engineering Thermodynamics Lab
Lab Instructors
Muhamad Zuhairi SulaimanIdris Bin Mat SahatProf. Dr. K. V. Sharma
Amir Bin Abdul Razak Mohd Razali Bin Hanipah
Lab Location Thermodynamics Laboratory, FKM
Lab Outcomes
By the end of the semester, student should be able to:
1. Define and explain the boundary layer concept2. Distinguish between free and forced convective mechanisms and the non-
dimensional numbers/parameters representing them.3. Identify equations applicable for the estimation of free/force convective heat
transfer coefficient for different geometries and flow conditions (laminar andturbulent).
4. Apply the concept and theoretical analysis of fins (for rectangular cross-section)5. Distinguish between the mechanism of heat flow from a single fin and a fin
array 6. Evaluate the heat transfer coefficients for different fin arrays under free and
Convection is a mode of heat transfer which takes place between a surface and a fluid.
Convective process is accomplished by the transfer of heat from a solid (at a higher
temperature) to a fluid (at a lower temperature) adjacent to the surface. The energytransfer by convection due to temperature difference can be due to random molecular motion
(diffusion) and macroscopic or bulk motion of fluid. Bulk flow of fluid occurs when the flow is
due to external means, such as by a fan, a pump or atmospheric winds and called as Forced
convection. The flow induced by buoyancy forces which arise from density differences caused
by temperature variations in a fluid is natural or free convection. The quantity of heat flow
by convection is evaluated using the Newton's law of cooling given by
21 T T hAQ s
where the proportionality constant h is the heat transfer coefficient. The theoreticalestimation of convective heat transfer coefficient is obtained by solving the equations of
continuity, momentum and energy with the concept of boundary layer. Hence the properties
of the fluid such as thermal conductivity and viscosity play an important role in the transfer
of energy by convection.
2.0 Unit Design
Legend
A = Fan
B = Air duct
C, D , H = Temperature points (H = T1, D = T2, C = T3)
Student need to address the following points with figs wherever necessary.
1. Define and explain the boundary layer concept
2. Distinguish between free and forced convective mechanisms and the non-dimensional
numbers/parameters representing them.
3. Identify equations applicable for the estimation of free/force convective heat transfer
coefficient for different geometries and flow conditions (laminar and turbulent).
4. Apply the concept and theoretical analysis of fins (for rectangular cross-section)
5. Distinguish between the mechanism of heat flow from a single fin and a fin array
6. Evaluate the heat transfer coefficients for different fin arrays under free and forced
convection.
Students may also explain any other term or equation relevant to convective phenomenon
4.0 Operational guidelines
1. Place the LS-17004-FFC Free and forced convection apparatus on a level table. Adjust theadjustable levelling foot is necessary.
2. Plug the 3 pin plug to the 240VAC main power supply. Turn ON the power supply.
3. Switch ON the power supply unit ( K ) in front of the control panel.
4. Select the desired test specimen (i.e F, G, Q ). Take the dimensions of the test specimenfrom the operation manual.
5. Place the test specimen to the plate heater placement ( P). Lock it with the wing nutsprovided.
6. Connect the test specimen heater cable to the heater socket which is located at the backof the control panel.
7. Take the digital handheld temperature probe and meter, measure the initial temperature(T i) in the air duct by putting the temperature probe into temperature point E. ( Ensurethe fan is OFF).
8. After read the temperature at point E, place the temperature probe to point D.
1. Read the safety instruction given before conducting the experiment.
2. Read and understand the theory for free convection before lab session.
3. Prepare the accessories needed for the experiment.
Accessories
1. LS-17004-FFC Free and Forced Convection Apparatus
2. Handheld temperature probe and meter
3. Vertical plate heater
4. Cylindrical plate heater
5. Finned plate heater
5.0 Observations
Present your experimental data in the form of tables
6.0 Discussion of Results
List the results in the form of statements and numerical values. Show details of theanalysis and numerical calculation involved. Appropriate graph might be used for results demonstration and elaboration.
7.0 Conclusions
Give your conclusions based on the experimental results
8.0 Questions
1. Briefly state and explain the error that might be occurs in the experiment?
2. Give 3 examples and briefly explain of the heat convection application includingbut not limit to industrial and environment.
9.0 References
State any references used.
Acknowledgement
Thanks to the following staffs for their contributions in preparing the laboratory sheet:
