Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 5, Problem 5.105P
Problem 4.9 addressed radioactive wastes stored under-ground in a spherical container. Because of uncertainty in the thermal properties of the soil, it is desired to measure the steady-state temperature using a test container (identical to the real container) that is equipped with internal electrical heaters. Estimate how long it will take the test container to come within
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A hollow aluminum sphere, with an electrical heater in the center, is used in tests to determine the thermal conductivity of insulating materials. The inner and outer radii of the sphere are o.18 and o.21 m, respectively, and testing is done under steady-state conditions with the inner surface of the aluminum maintained at 250°C. In a particular test, a spherical shell of insulation is cast on the outer surface of the sphere to a thickness of o.15 m. The system is in a room for which the air temperature is 20°C and the convection coefficient at the outer surface of the insulation is 30 W/m2. K. If 80 W is dissipated by the heater under steady-state conditions, what is the thermal conductivity of the insulation?
A cylinder 6”in diameter and 18”long is suspended horizontally in a largeroom. The air and wall surfaces of the room are at a temperature of 60 °Fwhile the surface temperature of the cylinder is 440 °F. Compute (a) thesurface coefficient due to free convection, (b) the heat transferred by freeconvection (neglecting the end areas), (c) the surface coefficient due toradiation if the surface emissivity is 0.75, and (d) the total heattransferred by free convection and radiation (neglecting end areas)
A prospective client attending the forum has requested consultancy services. You have requested the
specifications of the system and the client informs you that the exterior walls of a building are a
composite consisting of 12mm thick plaster board, 52mm thick urethane foam, and 12mm thick soft
wood. On a typical winter day, the outside and inside air temperatures are -14°C and 23°C respectively.
The outer and inner convection coefficients are 15W/mK and 5W/mK respectively.
c) Calculate the heating loss for a 1m2
section of the wall.
Chapter 5 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 5 - Consider a thin electrical heater attached to a...Ch. 5 - The inner surface of a plane wall is insulated...Ch. 5 - A microwave oven operates on the principle that...Ch. 5 - A plate of thickness 2L, surface area As, mass M,...Ch. 5 - For each of the following cases, determine an...Ch. 5 - Steel balls 12 mm in diameter are annealed by...Ch. 5 - Consider the steel balls of Problem 5.6, except...Ch. 5 - The heat transfer coefficient for air flowing over...Ch. 5 - A solid steel sphere (AISI 1010), 300 mm in...Ch. 5 - A flaked cereal is of thickness 2L=1.2mm. The...
Ch. 5 - The base plate of an iron has a thickness of L=7mm...Ch. 5 - Thermal energy storage systems commonly involve a...Ch. 5 - A tool used for fabricating semiconductor devices...Ch. 5 - A copper sheet of thickness 2L=2mm has an initial...Ch. 5 - Carbon steel (AISI 1010) shafts of 0.1-m diameter...Ch. 5 - A thermal energy storage unit consists of a large...Ch. 5 - Small spherical particles of diameter D=50m...Ch. 5 - A spherical vessel used as a reactor for producing...Ch. 5 - Batch processes are often used in chemical and...Ch. 5 - An electronic device. such as a power transistor...Ch. 5 - Molecular electronics is an emerging field...Ch. 5 - A plane wall of a furnace is fabricated from plain...Ch. 5 - A steel strip of thickness =12mm is annealed by...Ch. 5 - In a material processing experiment conducted...Ch. 5 - Plasma spray-coating processes are often used to...Ch. 5 - The plasma spray-coating process of Problem 5.25...Ch. 5 - A chip that is of length L=5mm on a side and...Ch. 5 - Consider the conditions of Problem 5.27. In...Ch. 5 - A long wire of diameter D=1mm is submerged in an...Ch. 5 - Consider the system of Problem 5.1 where the...Ch. 5 - Shape memory alloys (SMAs) are metals that undergo...Ch. 5 - Before being injected into a furnace, pulverized...Ch. 5 - As noted in Problem 5.3, microwave ovens operate...Ch. 5 - A metal sphere of diameter D, which is at a...Ch. 5 - A horizontal structure consists of an LA=10...Ch. 5 - As permanent space stations increase in size....Ch. 5 - Thin film coatings characterized by high...Ch. 5 - A long. highly polished aluminum rod of diameter...Ch. 5 - Thermal stress testing is a common procedure used...Ch. 5 - The objective of this problem is to develop...Ch. 5 - In thermomechanical data storage, a processing...Ch. 5 - The melting of water initially at the fusion...Ch. 5 - Consider the series solution, Equation 5.42, for...Ch. 5 - Consider the one-dimensional wall shown in the...Ch. 5 - Copper-coated, epoxy-tilled fiberglass circuit...Ch. 5 - Circuit boards are treated by heating a stack of...Ch. 5 - A constant-property, one-dimensional plane slab of...Ch. 5 - Referring to the semiconductor processing tool of...Ch. 5 - Annealing is a process by which steel is reheated...Ch. 5 - Consider an acrylic sheet of thickness L=5mm that...Ch. 5 - The 150-mm-thick wall of a gas-fired furnace is...Ch. 5 - Steel is sequentially heated and cooled (annealed)...Ch. 5 - Stone mix concrete slabs are used to absorb...Ch. 5 - During transient operation, the steel nozzle of a...Ch. 5 - Two plates of the same material and thickness L...Ch. 5 - In a tempering process, glass plate, which is...Ch. 5 - The strength and stability of tires may be...Ch. 5 - A plastic coating is applied to wood panels by...Ch. 5 - A long rod of 60-mm diameter and thermophysical...Ch. 5 - A long cylinder of 30-mm diameter, initially at a...Ch. 5 - A long pyroceram rod of diameter 20 mm is clad...Ch. 5 - A long rod 40 mm in diameter, fabricated from...Ch. 5 - A cylindrical stone mix concrete beam of diameter...Ch. 5 - A long plastic rod of 30-mm diameter...Ch. 5 - As part of a heat treatment process, cylindrical,...Ch. 5 - In a manufacturing process, long rods of different...Ch. 5 - The density and specific heat of a particular...Ch. 5 - In heat treating to harden steel ball bearings...Ch. 5 - A cold air chamber is proposed for quenching steel...Ch. 5 - Stainless steel (AISI 304) ball bearings. which...Ch. 5 - A sphere 30 mm in diameter initially at 800K is...Ch. 5 - Spheres A and B are initially at 800K. and they...Ch. 5 - Spheres of 40-mm diameter heated to a uniform...Ch. 5 - To determine which parts of a spider's brain are...Ch. 5 - Consider the packed bed operating conditions of...Ch. 5 - Two large blocks of different materials. such as...Ch. 5 - A plane wall of thickness 0.6 m (L=0.3m) is made...Ch. 5 - Asphalt pavement may achieve temperatures as high...Ch. 5 - A thick steel slab...Ch. 5 - A tile-iron consists of a massive plate maintained...Ch. 5 - A simple procedure for measuring surface...Ch. 5 - An insurance company has hired you as a consultant...Ch. 5 - A procedure for determining the thermal...Ch. 5 - A very thick slab with thermal diffusivity...Ch. 5 - Standards for firewalls may be based on their...Ch. 5 - It is well known that, although two materials are...Ch. 5 - Two stainless steel plates...Ch. 5 - Special coatings are often formed by depositing...Ch. 5 - When a molten metal is cast in a mold that is a...Ch. 5 - Joints of high quality can be formed by friction...Ch. 5 - A rewritable optical disc (DVD) is formed by...Ch. 5 - Ground source heat pumps operate by using the...Ch. 5 - To enable cooking a wider range of foods in...Ch. 5 - Derive an expression for the ratio of the total...Ch. 5 - The structural components of modem aircraft are...Ch. 5 - Consider the plane wall of thickness 2L, the...Ch. 5 - Problem 4.9 addressed radioactive wastes stored...Ch. 5 - Derive an expression for the ratio of the total...Ch. 5 - Prob. 5.107PCh. 5 - Prob. 5.108PCh. 5 - A thin rod of diameter D is initially in...Ch. 5 - A one-dimensional slab of thickness 2L is...Ch. 5 - Prob. 5.114PCh. 5 - Prob. 5.115PCh. 5 - A molded plastic product...Ch. 5 - Prob. 5.133PCh. 5 - A thin circular disk is subjected to induction...Ch. 5 - Two very long (in the direction normal to the...Ch. 5 - Prob. 5S.2PCh. 5 - Prob. 5S.3PCh. 5 - Estimate the time required to cook a hot dog in...Ch. 5 - Prob. 5S.7PCh. 5 - Prob. 5S.9PCh. 5 - Prob. 5S.10PCh. 5 - Prob. 5S.11PCh. 5 - Prob. 5S.13P
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
- Question 2: The composite wall of an oven consists of three materials, two of which are of known thermal conductivity, kA 20 W/m K and kC50 W/m K, and known thickness, LA 0.30 m and LC 0.15 m. The third material, B, which is sandwiched between materials A and C, is of known thickness, LB 0.15 m, but unknown thermal conductivity kB. Under steady-state operating conditions, measurements reveal an outer surface temperature of Ts,o 20°C, an inner surface temperature of Ts,i 600°C, and an oven air temperature of T 800°C. The inside convection coefficient h is known to be 25 W/m2 K. What is the value of kB?arrow_forwarda) Assuming perfect thermal contact between the layers of the composite walls, draw the typical temperature distribution across the layers and determine the heat energy gained per hour through all 4 walls of the room with a total surface area of 20 m2 . What does this heat energy represent in terms of the refrigeration system of the cold room? b) Without any calculations, how would you expect the internal and external air temperatures to be relative to the wall surface temperatures? Explain your answer. c) How do you expect the heat gain calculated in question 1a) above to change if you take into account the floor and the ceiling of the cold room? Explain your answerarrow_forwardSputnik 1, the first satellite launched into space by the Russians in 1957, is a 2-shell aluminum alloy (2024-T6) sphere. The highly polished outer shell (seeing deep space) is 585 mm in diameter, and has thickness of 1 mm (ID = 583 mm). The inside shell is 2 mm thick. There is a contact resistance between the two aluminum shells of value Rc"= 200 m2·K/W. Inside the shell, there is a radio unit that is uniformly dissipating thermal energy of Qradio = 1 W. Determine the steady-state temperature on the inner shell’s inner wall (ignore the effects of the antennas). Hint: You can use a radiation heat transfer coefficient hr = εσTshell3arrow_forward
- It is designed in such a way that the internal temperature of a commercial heat treatment furnace can reach up to 165 oC. All surfaces of the furnace consist of firebrick (10 cm), insulation material and sheet metal (3mm) from the inside out. Given that the outdoor temperature is 22 oC, the outer sheet will be allowed to go up to 35 oC, which is a temperature that will not be disturbed by hand contact. In this case, determine the insulation material thickness to be used. Insulation material thermal conductivity coefficient is 0.066 insulation W / m oC, 60 W / m oC for sheet metal and 115 W / m oC for firebrick. Indoor heat transfer coefficient will be accepted as 25 W / m2 oC and 12 W / m2 oC for outdoor environment.arrow_forwardAs part of your work-study program at HTU, you successfully got a student job at your local ‘BEST-BURGER-IN-TOWN’ to help pay your own tuition and expenses. Since cylindrical frozen burger patties are cooked when placed on a hot stainless-steel cooking top, you like to think of the case as a conduction problem:a. Write down the appropriate general heat conduction equation that describes the cooking of those beef patties.b. Clearly state all assumptions.c. After cancelling the proper terms, write down the final energy equation for the patties.Do not solve for temperature distribution or heat transfer.arrow_forwardCodfish fillets originally at 10 °C are packed to a thickness of 102 mm. Ice is packed on both sides of the fillets and wet-strength paper separates the ice and fillets. The surface temperature of the fish can be assumed as essentially 0 °C. Calculate the time for the center of the fillets to reach 2.22 °C and the temperature at this time at a distance of 25.4 mm from the surface. Also, plot temperature versus position for the slab using a spreadsheet software. The physical properties are k = 0.571 W/m*K, ρ = 1052 kg/m3, and Cp = 4.02 kJ/kg*K. Use Heissler charts to answer this question.arrow_forward
- A long wire of diameter D = 2 mm is submerged in an oil bath of temperature T∞ = 23°C. The wire has an electrical resistance per unit length of Re′=0.01 Ω/m. If a current of I = 180 A flows through the wire and the convection coefficient is h = 529 W/m2 · K, what is the steady-state temperature of the wire? From the time the current is applied, how long does it take for the wire to reach a temperature that is within 2°C of the steady-state value? The properties of the wire are ρ = 2,334 kg/m3, c = 537 J/kg · K, and k = 43 W/m · K.arrow_forwardIn a solar collector 1 m wide by 4 m long, the glass cover plate at an average temperature of 29°C is spaced 40 mm from the absorber plate at an average temperature of 75°C. Estimate the convection heat loss coefficient from the absorber plate to the glass when the collector is positioned horizontally. What is the convection heat loss coefficient if the spacing reduced to 10 mm?arrow_forwardPresents the diagram of the problem, necessary formulas, clearance and numerical solution: Two heat reservoirs with respective temperatures of 325 and 275 K are brought into contact by an iron rod 200 cm long and 24 cm2 in cross section. Calculate the heat flux between the reservoirs when the system reaches its steady state. The thermal conductivity of iron at 25 ◦C is 79.5 W/m K.arrow_forward
arrow_back_ios
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