Module 4.1
Measurement of thermophysical properties
Quadrant 2
List of animations/Videos:
Thermal conductivity:
1. Experiments on thermal conductivity – 3 experiments are presented:
http://www.youtube.com/watch?v=XbOQCiGHaZE
2. Heat conduction experiment is conducted:
http://www.youtube.com/watch?v=W4C49pUGrTI
3. Classic thermal conductivity experiment – thermal conductivity of 5 metal rods
(aluminium, brass, copper, steel, zinc) are measured (qualitative demonstration).
http://www.youtube.com/watch?v=SNG_5lPe2a8
4. Thermal conductivity of liquids, pastes, powders :
http://www.youtube.com/watch?v=fIDAAcgndG4
Calorific value of fuels / Heat capacity of liquids:
5. Specific heat of a liquid by cooling method
http://www.youtube.com/watch?v=QvKlLjRJAAA
6. Specific heat of a liquid : http://www.youtube.com/watch?v=S9JSR2zpYKk
7. Specific heat capacity explained : http://www.youtube.com/watch?v=BclB8UaSH4g
8. Specific heat of a metal : http://www.youtube.com/watch?v=8gHFaL2990U
9. Specific heat capacity of water : http://www.youtube.com/watch?v=caoneXrvp9k
10. Bomb calorimeter working animation :
http://www.youtube.com/watch?v=YXo9B2AbH0s
11. Bomb calorimeter experimental procedure:
http://www.youtube.com/watch?v=Dn817kYC4tw
12. Bomb calorimetry , setup and operation:
http://www.youtube.com/watch?v=ohyA9amFfsc
13. Determination of calorific value using bomb calorimeter (Hindi) :
http://www.youtube.com/watch?v=9suiA6EWQ18
14. Bomb calorimeter, problems and solutions :
http://www.youtube.com/watch?v=3VkWpycr5xA
15. Coffee cup calorimeter : http://www.physicsclassroom.com/class/thermalP/u18l2c.cfm
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16. Bomb calorimeter : http://highered.mcgrawhill.com/sites/9834092339/student_view0/chapter48/bomb_calorimeter.html
17. The oxygen bomb calorimeter animation : http://web.mst.edu/~gbert/animation.html
Viscosity of fluids:
18. Viscosity video, definition of viscosity, shear viscosity, kinematic viscosity, bulk viscosity,
Newtonian and non-Newtonian fluids, viscosity in solids, viscosity measurement, units,
viscosity of fluids are presented
http://en.wikipedia.org/wiki/Viscosity
19. What is viscosity? Viscosity of milk and honey are compared. Molecular forces are
explained. Effect of temperature on viscosity is explained.
http://www.youtube.com/watch?v=1AESWxko4nI
20. Lecture on viscosity : http://www.youtube.com/watch?v=xTeA_YYlMMI
21. Lecture on Viscosity – dynamic and kinematic viscosity :
http://www.youtube.com/watch?v=fPPE3KB7G-s
22. Viscosity of liquids –comparison of viscosity of different liquids
http://www.youtube.com/watch?v=3KU_skfdZVQ
23. Determination of Viscosity co-efficient of a given liquid using Ostwald's Viscometer
http://www.youtube.com/watch?v=yekYoNxcH5Y
viscosity of non-Newtonian fluid using Brookfield rotational viscometer
http://www.youtube.com/watch?v=AGcyXbASPZc
24. Viscosity of water and glycerine are compared :
http://www.youtube.com/watch?v=x0Y9XJvHwD0
25. Viscosity measurement using viscotube
http://www.youtube.com/watch?v=J6SdO4INiBo
26. Viscosity measurement using Ostwald’s viscometer
http://www.youtube.com/watch?v=Gs3gfwG9a7k
27. Demonstration of viscometer : http://www.youtube.com/watch?v=TPfjX9EtmyA
28. Viscosity of Newtonian Fluids using Haake falling ball viscometer :
http://www.youtube.com/watch?v=wmQTjtKOmCQ
29. Rotational viscometer : http://www.youtube.com/watch?v=M3y7hXT3Qcs
30. TQC Rotational Viscometer according to Brookfield Method, allows quick determination
of viscosity in laboratory, research centres, and during production. The intuitive, easy
functionality, light weight, and the fact they are battery operated provide great
versatility. TQC Rotational Viscosimeter can even be used as a portable instrument.
http://www.youtube.com/watch?v=1_oZfaEIYII
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31. Viscometer calibration using coaxial cylinder geometry :
http://www.youtube.com/watch?v=EL5OYjuAH7g
32. How to use a viscometer- calibration : http://www.youtube.com/watch?v=7Y03qNtzUzE
Illustrations:
1. Viscosity measurement of glass (schematic of parallel plate viscometer is shown
http://glassproperties.com/viscosity/ViscosityMeasurement.htm
2. Different types of viscometers are presented
http://www.iitk.ac.in/transEL/tests_details/viscosity%20test.htm
List of questions (FAQ):
Thermal conductivity:
1. Define thermal conductivity. What is calorimetry?
2. Write the defining equation for thermal conductivity
3. With usual notations write equations for thermal conductivity. Write the assumptions
made.
4. Explain guarded hot plate apparatus for solid sample with a neat diagram.
5. Explain guarded hot plate apparatus for liquid sample with a neat diagram.
6. Explain radial heat conduction apparatus for liquids and gases, with a neat sketch.
7. With a neat sketch explain thermal conductivity comparator.
8. With a neat schematic diagram, explain the principle and working of a laser flash
apparatus.
Calorific value of fuels / Heat capacity of liquids:
9. Write a note on heat capacity and its measurement.
10. With suitable equations, give a brief account on heat capacity of a solid.
11. Write a note on heat capacity of liquid
12. How is calorific value of fuels measured?
13. List the different processes in a calorimeter experiment.
14. Explain Bomb calorimeter with a neat diagram
15. Explain continuous flow calorimeter and write the energy balance equation.
Viscosity of fluids:
16. How is viscosity of fluids measured? Explain.
17. Name the different methods employed to measure viscosity
18. Explain, how laminar flow in a capillary is used to measure viscosity, with neat sketch.
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19. Explain Saybolt viscometer
20. Explain rotating cylinder viscometer, with a neat sketch.
Quadrant 3
Wiki links/reference links/courses from other university websites/case studies:
Thermal conductivity:
1. Units of thermal conductivity, experimental values, definitions, influencing factors are
discussed in this link: http://en.wikipedia.org/wiki/Thermal_conductivity
2. Thermal conductivity of some common metals are listed :
http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html
3. Thermal conductivity measurement experimental details are presented:
http://physics.niser.ac.in/labmanuals/sem2/Thermal%20Conductivity%20of%20metals.pdf
4. Correlations for the thermal conductivity of metals as a function of temperature- an
article : International Journal of Thermophysics, Vol. 22, No. 6, November 2001
5. Thermal Conductivity of Metals: Which Metal Is the Best Conductor of Heat? :
http://www.education.com/science-fair/article/which-metal-conducts-heat-best/
6. Thermal conductivity by guarded hot plate apparatus as per ASTM c-177, IS-3349 is
shown in this site : http://www.scdey.com/thermal.html
7. Design and function of the guarded hot plate apparatus details are presented :
http://www.lambda-messtechnik.de/en/thermal-conductivity-test-tool-ep500e/guarded-hotplate-apparatus-lambda-meter-ep500e-design-and-function.html
8. Determination of thermal conductivity, thermal conductivity of selected building
materials ( at about 20 deg C), Measuring methods, scheme of guarded hot plate
method, ISOMET apparatus, determining thermal conductivity in steady state, Dr. Bock’s
apparatus, testing procedure are explained :
http://tpm.fsv.cvut.cz/student/documents/files/BUM1/Chapter16.pdf
9. A guarded hot plate apparatus for thermal conductivity measurements over the
temperature range -75 to 200 deg C- a journal paper:
http://link.springer.com/article/10.1007%2FBF00508892#page-1
10. Thermal conductivity measurement, steady-state methods, transient method, transient
plane source method, MTPS method, transient line source method, laser flash method,
3 omega method are explained :
http://en.wikipedia.org/wiki/Thermal_conductivity_measurement
11. Daniel R. Flynn, Robert R. Zarr, Mahn Hee Hahn, and William M. Healy
Design Concepts for a New Guarded Hot Plate Apparatus for Use Over an Extended
Temperature Range- an article : http://fire.nist.gov/bfrlpubs/build02/PDF/b02085.pdf
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12. A guarded hot plate method for measuring the thermal conductivity of metals and nonmetals (1958), Thesis by Frank P : http://archive.org/details/guardedhotplatemet00schl
13. Different methods for thermal conductivity measurement are explained with necessary
figures and equations: http://www.azom.com/article.aspx?ArticleID=5615
14. Images of thermal conductivity measurement setups :
https://www.google.co.in/search?q=thermal+conductivity+measurement+setup&tbm=i
sch&tbo=u&source=univ&sa=X&ei=rwQ0UvvRIs2Orgebi4CgDw&ved=0CH4QsAQ&biw=1
280&bih=634&dpr=1
15. Experimental setup for the measurement of the thermal conductivity of liquids – a
research article by Codreanu and others, :
http://www.imt.ro/romjist/Volum10/Number10_3/pdf/01-Codreanu.pdf
16. Thermal conductivity instrument for analyzing thermal conductivity, thermal diffusivity
and specific heat of solids, liquids, paste and powders is displayed :
http://www.thermtest.com/
17. Measuring the thermal conductivity of liquids using photo-thermal radiometry – an
article by Kusiak and others : http://iopscience.iop.org/0957-0233/21/1/015403
18. Laser flash method for measuring thermal conductivity of liquids – application to low
thermal conductivity liquids- a research article by Yutaka Tada and others :
http://repo.lib.nitech.ac.jp/bitstream/123456789/4320/1/RSI
19. Thermal conductivity measurement of liquids in a microfluidic device –a research article
by Kuvshinov and others :
http://www.academia.edu/416065/Thermal_conductivity_measurement_of_liquids_in_
a_microfluidic_device
Calorific value of fuels:
20. Heat of combustion, calorific value, measuring calorific value, heat of combustion tables
: http://en.wikipedia.org/wiki/Heat_of_combustion
21. Images of bomb calorimeter :
https://www.google.co.in/search?q=bomb+calorimeter&tbm=isch&tbo=u&source=univ&sa=X&
ei=iOU2UoGiM4a4rgfxj4HQBQ&sqi=2&ved=0CE0QsAQ&biw=1280&bih=677&dpr=1
22. Calorimeter – different types are explained : http://en.wikipedia.org/wiki/Calorimeter
23. Purpose of bomb calorimeter, construction, calibration, corrections, application, other
types of calorimeters :
http://www.chem.hope.edu/~polik/Chem345-2000/bombcalorimetry.htm
24. Microprocessor bomb calorimeter by Toshniwal :
http://www.toshniwaldelhi.com/bomb-calorimetry.html
Heat capacity measurement:
Page 5 of 15
25. Flash method of determining thermal diffusivity, heat capacity and thermal conductivity
:http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5124748&abstractAccess=no&userTy
pe=inst
26. Heat capacity, units, quantities, measurement, thermodynamic relations and definitions,
theory of heat capacity …. : http://en.wikipedia.org/wiki/Heat_capacity
27. Images of heat capacity measurement :
https://www.google.co.in/search?q=heat+capacity+measurement&tbm=isch&tbo=u&source=u
niv&sa=X&ei=Ng00Usy9L4iPrQeC0YGoDQ&ved=0CEMQsAQ&biw=1280&bih=677&dpr=1
Viscosity of fluids:
28. Standard laboratory Viscometers are explained with necessary diagrams
http://en.wikipedia.org/wiki/Viscometer
29. How to measure viscosity? – 12 steps are presented.
http://www.wikihow.com/Measure-Viscosity
30. Viscosity and its nomenclature, theory, experiments and procedures, problems are
presented.
http://www.ias.ac.in/initiat/sci_ed/resources/chemistry/Viscosity.pdf
31. Why measure viscosity? Applications of viscosity, powder flow applications, viscosity
values of some materials.
http://www.brookfieldengineering.com/education/applications/index.asp
32. Viscosity measurement – experimental procedure – Thomas Stormer viscometer
http://web.cecs.pdx.edu/~gerry/class/EAS361/lab/pdf/lab1_viscosity.pdf
33. A simple viscosity test procedure :
http://www.stanford.edu/group/cpima/education/EDKIT/other%20lessons/viscosity.pdf
34. Liquid viscosity measurement using capillary tube viscometer, cone and plate
viscometer, Saybolt viscometer – Lab manual :
http://pete.metu.edu.tr/files/216labmanual.pdf
35. To measure relative viscosity and determine the viscosity-composition curve for a twocomponent liquid system:
http://www.che.boun.edu.tr/courses/che203/ChE203_Experiment1.pdf
36. Falling sphere viscometer basics are illustrated
http://moodle.sbc.ac.uk/sharedContent/repository/to_be_packaged/Engineering,Techn
ology%20and%20Manufacturing/Manufacturing/The%20Measurement%20of%20Viscos
ity/SC2_RESOURCE_SCREEN_3/SC2_RESOURCE_SCREEN_3.html
Quadrant 4
Page 6 of 15
Numerical problems:
1. A guarded hot plate apparatus is used to measure the thermal conductivity of an
insulating material. The specimen thickness is 25 ± 0.5 mm. the heat flux is measured
within 1 % and is nominally 150 W/m2 . the temperature drop across the specimen
under the steady state is 5 ± 0.2 o C. Determine the thermal conductivity of the sample
along with its uncertainty.
Solution:
Given,
Heat flux = q = 150 W/m2
Temperature drop = ∆T = 5 o C
Specimen thickness = δ = 0.025 m
Nominal value of thermal conductivity = k = q δ/ ∆T = 0.75 W/m oC
The uncertainities are specified as given below:
u q = ± 150/100 = ± 1.5 W/m2
u ∆T = ± 0.2 oC
u δ = ± 0.0005 m
Error in the thermal conductivity is u k = ± k � (
2
𝑢𝑞
𝑞
+
𝑢2∆T
∆T
After substitution and simplification, error in u k = ±0.116
+
𝑢δ2
δ
)
Multiple choice questions (Choose the correct answer)
Thermal conductivity:
1. The thermal energy transfer by direct collisions, particle-to particle is called ...
a. radiation
b. conductive
c. conduit
d. convective
2. Following method is used to measure thermal conductivity in unsteady state
a. laser flash apparatus
b. guarded hot plate apparatus
c. radial heat flow apparatus
d. thermal conductivity comparator
Page 7 of 15
3. Select the wrong statement
a. thermal conductivity is always higher in the purest form of metal
b. heat treatment causes considerable variation in thermal conductivity
c. thermal conductivity of a wet material is considerably higher than the
thermal conductivity of the dry material and water taken individually
d. thermal conductivity decreases with increase in the density of the
substance
Calorific value of fuels:
4. The bomb calorimeter is frequently used for determining the following, in solids and
liquid fuels.
a. Heating value
b. Viscosity
c. Density
d. Thermal conductivity
5. Which of the following gaseous fuels does not have different higher and lower calorific
values of fuel?
a. methane
b. ethane
c. carbon monoxide
d. hydrogen
6. The higher calorific value of fuel occurs when water vapour
a. present in products of combustion is condensed to the initial temperature of
the fuel
b. present in the products of combustion is not condensed to the initial
temperature of the fuel
c. is not formed during the combustion of fuel
d. is formed during combustion of fuel
7. Which of the following constituents of a fuel does not contribute to its calorific value on
combustion?
a. carbon
b. hydrogen
c. sulphur
d. nitrogen
8. Bomb calorimeter is used to determine
a. calorific value of solid as well as liquid fuels
b. calorific value of gaseous fuels
Page 8 of 15
c. ash content of solid fuels
d. incombustible matter in solid fuel
9. Select the wrong statement
a. liquid fuels have higher calorific value than solid fuels
b. a good fuel has a high ignition point
c. coal gas consists mainly of hydrogen, carbon monoxide and various
hydrocarbons
d. calorific value of a gaseous fuel is expressed in kJ/m3
Viscosity of fluids:
10. In using capillary tube viscometer correction is needed for
a. Change in density
b. Change in temperature
c. Change in gravitational constant
d. Losses in head
11. In Saybolt viscometer, the viscosity can be measured by measuring the time required to
fill a flask with liquid volume --------- ml
a. 50
b. 200
c. 60
d. 10
12. Unit of viscosity in SI units is
a. Ns/m2
b. Kg.sec/m2
c. m2/sec
13. In rotating cylinder viscometer, the quantity normally measured is
a. Torque transmitted
b. Outer cylinder speed
c. Height of oil film
14. In efflux viscometers, the viscosity is determined -------, for a specified volume of fluid
through a capillary
a. By recording time of efflux
b. By noting the volume of fluid
c. By noting the height of oil film
15. Falling sphere method is method to measure the following:
a. Temperature
Page 9 of 15
b. Flow rate
c. Viscosity
d. Pressure
Answer table
1. b
2. a
3. d
4. a
5. c
6. a
7. d
8. a
9. b
10. d
11. c
12. a
13. a
14. a
15. c
True/false
Thermal conductivity:
16. Thermal conductivity of gases increase with increase in temperature
17. When a copper pipe is heated, it gets wider and longer
Viscosity of fluids:
18. Viscosity is the property of a fluid which determines its resistance to shear stresses
19. The relative viscosity of a liquid with respect to water is determined by the Ostwald
apparatus
20. Viscosity is a property of the liquid that arises because of a frictional force between the
solid object and the adjacent layer of the liquid as the object moves through it
Answer table
16. T
17. T
18. T
19. T
20. T
Page 10 of 15
Fill in the blanks with appropriate word/s
Thermal conductivity/calorific value of fuels/ Heat capacity measurement:
21. In a pot of boiling water, the temperatures of the liquid water and steam are-------22. Food in microwave oven gets heated up by ------------------23. Egg on a frying pan is heated by -------------------24. Thermal conductivity and viscosity are also known as ---------------- properties
25. The steady state methods of measuring thermal conductivity are generally termed as --------------- methods
26. --------------- is an important thermo-physical property that is routinely measured in the
laboratory
27. Laser flash method is used to measure --------------- under unsteady category
28. For determining the thermal conductivity of good conductors, such as metals and alloys,
---------------------------method is especially useful
29. Calorific value of gaseous fuels can be found by ----------Viscosity of fluids:
30. The apparatus used for viscosity measurement is called -------------------31. --------------viscometer is extensively used in petroleum and allied industries
32. Viscosity is a property of a fluid which offers its resistance to ------------------stresses
33. An ideal fluid is one with -------- viscosity
34. Viscosity of fluids is due to -------- and interaction between particles
35. Falling sphere method of measuring viscosity is based on --------36. For Newtonian fluids, the viscosity depends upon the pressure and --------------but not on velocity gradient
37. For non-Newtonian fluids, the viscosity depends on the pressure, temperature
and, ----------
Page 11 of 15
Answer table
21. Same temperature
22. Radiation
23. Conduction
24. Transport properties
25. Calorimetric
26. Heat capacity
27. Thermal conductivity
28. Thermal conductivity comparator
29. Junker’s calorimeter
30. Viscometer
31. Efflux viscometer or capillary
tube
32. Shearing
33. Zero
34. Cohesion
35. Stokes law
36. Temperature
37. Shear rate
Assignment questions and solutions
Thermal conductivity:
1. What is thermal conductivity?
Ans: A measure of the ability of a material to transfer heat. Given two surfaces on either
side of the material with a temperature difference between them, the thermal
conductivity is the heat energy transferred per unit time and per unit surface area,
divided by the temperature difference. It is measured in watts per degree Kelvin
2. Mention a few steady state methods of measuring thermal conductivity.
Ans: Guarded hot plate method
Radial heat conduction apparatus method
Thermal conductivity comparator method
Calorific value of fuels:
3. What is calorific value of a fuel? What are other terms used for this?
Ans: It is the thermal energy released per unit quantity of the fuel when the fuel is burnt
fully and the products of combustion are cooled back to the initial temperature of the
combustible mixture.
The other terms used for calorific value are heating value and heat of combustion
Viscosity of fluids:
4. Define viscosity of a fluid
Page 12 of 15
Ans: Viscosity is the property of a fluid which determines its resistance to shearing
stresses. It is a measure of the internal fluid friction which causes resistance to flow.
5. List the various methods used to measure viscosity
Ans:
Rotating cylinder ( co-axial cylinder) method
Falling sphere method
Capillary tube method
Efflux viscometers : Say bolt, Redwood, Engler meters
Rotameter (with 2 floats ) method (variable area viscometer)
Cone and plate viscometer method
6. How can we measure viscosity of a fluid continuously?
Ans: Using rotameter, containing 2 floats, we can measure viscosity continuously. The
lower float is insensitive to viscosity changes. The flow rate through rotameter is kept
constant, which is indicated by lower float. The upper float is sensitive to viscosity
changes. Viscous drag force changes its position as fluid viscosity changes. Thus,
distance between 2 floats is proportional to viscosity of fluid at a given temperature.
Also read: KSME International Journal ,February 2002, Volume 16, Issue 2, pp 255-261,
Continuous viscosity measurement of non-Newtonian fluids over a range of shear rates
using a mass-detecting capillary viscometer, Sehyun Shin, Do-Young Keum
Self answered questions and answers:
1. Write the defining equation for thermal conductivity.
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
2. What is a guarded hot-plate apparatus? Under what conditions it is applied?
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
3. Discuss the radial heat flow apparatus for solids and gases.
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
4. Discuss the following with necessary diagrams: (i)Thermal conductivity comparator,
(ii) laser flash method
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
Page 13 of 15
5. Discuss the construction of bomb calorimeter and explain how it is used for heating
value determination of solid fuels
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
6. Explain a calorimeter for the measurement of specific heat of a solid. Also, show a
typical temperature-time plot.
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
7. Explain how specific heat of liquids is measured.
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 , Measurement of thermo-physical properties)
8. Discuss with a schematic, measurement of viscosity of engine oil, using
Saybolt viscometer.
Ans: Please refer web resource nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical
_Measurements (Module 4.1 ,Measurement of thermo-physical properties, Fig.19)
9. State and explain Newton’s law of viscosity
Ans: This law states that the shear stress on a fluid element layer is directly proportional
to the rate of shear strain. For explanation, please refer web resource
nptel.iitm.ac.in/courses/IIT-MADRAS/Mechanical _Measurements (Module 4.1
,Measurement of thermo-physical properties, Fig.16)
Test your skills/knowledge:
1. Learn the meanings of the following terms: heat, heat flow, conductivity, thermal
conductivity, specific heat, calorific value. Mention the apparatus used to measure
these.
2. Learn the method of measuring the heat flow and thermal conductivity from
automobile engines.
3. Mention the calorific value of kerosene.
4. How the viscosity of kerosene is measured?
5. A photograph of an apparatus for thermal conductivity measurement of composite wall
is presented below. Identify the various elements of the apparatus.
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Thermal conductivity measurement of composite wall
Page 15 of 15