Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470917855
Author: Bergman, Theodore L./
Publisher: John Wiley & Sons Inc
expand_more
expand_more
format_list_bulleted
Videos
Question
Chapter 9, Problem 9.39P
To determine
The thermal conductivity and emissivity of sample.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A black thermocouple
measures the temperature in a
chamber with black walls. If the
air around the thermocouple is
at 20°C, the walls are at 100°C,
and the heat transfer
coefficient between the
thermocouple and the air is 15
W/m?K, what temperature will
the thermocoule read?
Calculate the heat transfer between two
(50*40 cm) parallel plates at constant
temperatures of 71 = 100 K and 72 = 50
K that are L = 1 cm apart, assuming the
emissivity (r) is 0.6 according to the
following conditions.
1. The parallel plates filled with
atmospheric air assume the thermal
conductivity at the average
temperature of 250 K is k=0.021
Heat
direction
Air Space
* 24140
Heat
direction
Super-insulation
W/m °C for air, Stefan-Boltzmann constant is 5.67*10*W/m².K'
2. The parallel plates are filled with super-insulated material and have an apparent
thermal conductivity of 0.00004 W/m - °C.
7.5 m
7.5 m
Which of the two configurations above should a company use if it plans on using a fire clay brick
refractory with k = 1.54 W/m °C? For the two configurations above, the wall thickness is 400 mm,
and the length is 15.75 m.
7.5 m
Chapter 9 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 9 - The one-dimensional plane wall of Figure 3.1 is of...Ch. 9 - Using the values of density for water in Table...Ch. 9 - Consider an object of Characteristic length 0.01 m...Ch. 9 - To assess the efficacy of different liquids for...Ch. 9 - In many cases, we are concerned with free...Ch. 9 - The heat transfer rate due to free convection from...Ch. 9 - Consider a large vertical plate with a uniform...Ch. 9 - For laminar free convection flow on a vertical...Ch. 9 - Consider an array of vertical rectangular tins,...Ch. 9 - A number of thin plates are to be cooled by...
Ch. 9 - Prob. 9.11PCh. 9 - Prob. 9.13PCh. 9 - The plate described in Problem 9.14 has been used...Ch. 9 - Determine the average convection heat transfer...Ch. 9 - Consider a vertical plate of dimension 0.025m0.50m...Ch. 9 - During a winter day, the window of a patio door...Ch. 9 - Prob. 9.20PCh. 9 - A household oven door of 0.5-m height and 0.7-m...Ch. 9 - Consider a vertical, single-pane window of...Ch. 9 - Consider laminar flow about a vertical isothermal...Ch. 9 - Consider the conveyor system described in Problem...Ch. 9 - Prob. 9.25PCh. 9 - Consider an experiment to investigate the...Ch. 9 - The vertical rear window of an automobile is of...Ch. 9 - Prob. 9.28PCh. 9 - Prob. 9.29PCh. 9 - Prob. 9.30PCh. 9 - A refrigerator door has a height and width of...Ch. 9 - In the central receiver concept of a solar power...Ch. 9 - Prob. 9.34PCh. 9 - Airflow through a long, 0.2-m-square air...Ch. 9 - Prob. 9.36PCh. 9 - An electrical heater in the form of a horizontal...Ch. 9 - Consider a horizontal 6-mm-thick, 100-mm-long...Ch. 9 - Prob. 9.39PCh. 9 - Prob. 9.40PCh. 9 - Prob. 9.41PCh. 9 - Many laptop computers are equipped with thermal...Ch. 9 - Prob. 9.43PCh. 9 - At the end of its manufacturing process, a silicon...Ch. 9 - Integrated circuit (IC) boards are stacked within...Ch. 9 - Prob. 9.48PCh. 9 - Prob. 9.50PCh. 9 - Prob. 9.51PCh. 9 - Prob. 9.52PCh. 9 - Prob. 9.53PCh. 9 - Prob. 9.54PCh. 9 - Prob. 9.55PCh. 9 - Prob. 9.56PCh. 9 - Prob. 9.57PCh. 9 - A horizontal tube of 12.5-mm diameter with an...Ch. 9 - Prob. 9.60PCh. 9 - Prob. 9.61PCh. 9 - Prob. 9.63PCh. 9 - Prob. 9.64PCh. 9 - Common practice in chemical processing plants is...Ch. 9 - Consider the electrical heater of Problem 7.49. If...Ch. 9 - Prob. 9.67PCh. 9 - A billet of stainless steel, AISI 316, with a...Ch. 9 - Lone stainless steel rods of 50-mm diameter are...Ch. 9 - Hot air flows from a furnace through a...Ch. 9 - A biological fluid moves at a flow rate of...Ch. 9 - A sphere of 25-mm diameter contains an embedded...Ch. 9 - Prob. 9.79PCh. 9 - A vertical array of circuit boards is immersed in...Ch. 9 - Prob. 9.81PCh. 9 - The front door of a dishwasher of width 580 mm has...Ch. 9 - A natural convection air healer consists of an...Ch. 9 - A bank of drying ovens is mounted on a rack in a...Ch. 9 - Prob. 9.85PCh. 9 - Prob. 9.86PCh. 9 - Prob. 9.87PCh. 9 - To reduce heat losses, a horizontal rectangular...Ch. 9 - Prob. 9.89PCh. 9 - Prob. 9.90PCh. 9 - Prob. 9.91PCh. 9 - Prob. 9.92PCh. 9 - A 50-mm-thick air gap separates two horizontal...Ch. 9 - Prob. 9.94PCh. 9 - A vertical, double-pane window, which is 1 m on a...Ch. 9 - The top surface (0.5m0.5m) of an oven is 60°C for...Ch. 9 - Prob. 9.97PCh. 9 - Prob. 9.98PCh. 9 - Consider the cylindrical. 0.12-m-diamter radiation...Ch. 9 - Prob. 9.100PCh. 9 - A solar collector design consists of an inner tube...Ch. 9 - Prob. 9.104PCh. 9 - Prob. 9.105PCh. 9 - Liquid nitrogen is stored in a thin-walled...Ch. 9 - Prob. 9.108PCh. 9 - Prob. 9.109PCh. 9 - Prob. 9.110PCh. 9 - Prob. 9.111PCh. 9 - Prob. 9.114PCh. 9 - Prob. 9.115PCh. 9 - Prob. 9.116PCh. 9 - Prob. 9.117PCh. 9 - A water bath is used to maintain canisters...Ch. 9 - On a very Still morning, the surface temperature...Ch. 9 - Fuel cells similar to the PEM cell of Example 1.5...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- 1.15 A thermocouple (0.8-mm-diameter wire) used to measure the temperature of the quiescent gas in a furnace gives a reading of . It is known, however, that the rate of radiant heat flow per meter length from the hotter furnace walls to the thermocouple wire is 1.1 W/m and the convection heat transfer coefficient between the wire and the gas is K. With this information, estimate the true gas temperature. State your assumptions and indicate the equations used.arrow_forward2.3 The shield of a nuclear reactor is idealized by a large 25-cm-thick flat plate having a thermal conductivity of . Radiation from the interior of the reactor penetrates the shield and there produces heat generation that decreases exponentially from a value of at the inner surface to a value of at a distance of 12.5 cm from the interior surface. If the exterior surface is kept at 38°C by forced convection, determine the temperature at the inner surface of the field. Hint: First set up the differential equation for a system in which the heat generation rate varies according to .arrow_forwardA spherical interplanetary probe of 0.5-m diameter contains electronics that dissipate 150 W. If the probe surface has an emissivity of 0.8 and the probe does not receive radiation from other surfaces, as, for example, from the sun, what is its surface temperature?arrow_forward
- Two parts and label (A) & (B) Solve carefully! Question : The roof of a car in a parking lot absorbs a solar radiant flux of 600 W/m2, while the underside is perfectly insulated. The convection coefficient between the roof and the ambient air is 15 W/m2.K and the roof’s surface emissivity is 0.5. If the ambient air temperature is 25C, answer the following questions: PART (A) Neglecting radiation heat transfer, find the temperature of the roof under steady state conditions. Part ( B) Neglecting convective heat transfer, find the steady state temperature of the roof [Tsur =0]?arrow_forwardA 30-m-long hot rod (Diameter = 100-mm) is placed inside a room whose walls and air are at 25 C. The surface temperature of the rod is 150 C. h=10 W/m K. The surface emissivity is: your student number/10. What is the rate of heat loss from the rod? student number =201810372 %3Darrow_forward3. Consider a 3 m high rectangular enclosure consisting of two surfaces separated by a 0.1 m air gap at 1 atm. If the surface temperatures across the air gap are 30 °C and -10 °C, determine the ratio of the heat transfer rate for the horizontal orientation (with hotter surface at the bottom) to that for vertical orientation. [1.66] 0.1 m 3 m Air -10°C -10°C 30°C Air 30°℃ > 3marrow_forward
- Question 11 Not yet answered Marked out of 2.50 P Flag question A cylindrical resistor element on a circuit board dissipates 0.23 W of power in an environment at 28°C. The resistor is 1.3 cm long, and has a diameter of 3 mm. Assuming heat to be transferred uniformly from all surfaces. What is the surface temperature of the resistor for a combined convection and radiation heat transfer coefficient of 13 W/m .°C? Select one: A. 157.46 B. 190.22 C. 168.73 D. 130.79 E. 143.48arrow_forward1-mm-diameter cylindrical resistor, insulated with a sheath of thermal conductivity, k, of 0.12 W/m-K, is located in an evacuated enclosure. The surface emissivity of the sheath is 0.85. The resistor is maintained at 450 K and the enclosure is at 300 K. What is the radius of the sheath that maximises the rate of heat loss from the resistor? Evaluate the corresponding maximum heat rate per unit length of the resistor and the sheath surface temperature. Determine the value of the parameter hirerlk where h, is the linearised radiation heat transfer coefficient at the critical radius, rer. Comment on your results. State all assumptions made. What is the rate of heat loss per unit length from the uninsulated resistor if its surface emissivity is the same as the sheath surface of the insulated resistor?arrow_forwardQUESTION 3 A rectangular window in a home has a length of 1.5 m and a height of 0.80 m. If the window allows heat to escape from the home at a rate of 2,000 watts, how thick must the window be if the inside temperature of the home is 220 c and the outside temperature is 3.0°C? (Assume that the coefficient of thermal conduction of glass is 0.80 W/mK.) а. 7.1 mm b. 11 mm C. 9.1 mm d. 124 mm e. 8.1 mmarrow_forward
- SOLVE STEP BY STEO IN DIGITAL FORMAT A 9-cm-diameter sphere, whose surface is maintained at a temperature of 110°C, is hanging in the center of a room at 20°C. If the convective heat transfer coefficient is 15 W/m²"C, and the emissivity of the surface is 0.8, calculate the total rate of heat transfer from the sphere. Air 20°C D=9 cm 110°Carrow_forwardA brass plate has a circular hole whose diameter is slightly smaller than the diameter of an aluminum ball. Ifthe ball and the plate are always kept at the same temperature,(a) should the temperature of the system be increased or decreasedin order for the ball to fit through the hole? (b) Choose the bestexplanation from among the following:I. The aluminum ball changes its diameter more with temperature than the brass plate, and therefore the temperatureshould be decreased.II. Changing the temperature won’t change the fact that the ballis larger than the hole.III. Heating the brass plate makes its hole larger, and that willallow the ball to pass through.arrow_forwardHeat is generated in a 1.4 m long and 0.2 cm diameter electrical resistance wire placed in the middle of a room kept at 20 degrees. Under continuous conditions, the surface temperature of the wire was measured as 180 ° C, the voltage drop on the wire as 110 V and the electric current as 3 A. Regardless of radiative heat transfer,Find the heat transfer coefficient for the heat transfer between the surface of the wire shown in the figure and the room air.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license