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
Textbook Question
Chapter 7, Problem 7.57P
In a manufacturing process, long aluminum rods of square cross section with
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Chips of width L _ 15 mm on a side are mounted to a substrate that is installed in an enclosure
whose walls and air are maintained at a temperature of Tsur=T∞=25oC. The chips have an emissivity of
ε=0.60 and a maximum allowable temperature of Ts=85oC.
(a) If heat is rejected from the chips by radiation and natural convection, what is the maximum operating
power of each chip? The convection coefficient may be approximated as h=11.7 W/m2K.
(b) If a fan is used to maintain airflow through the enclosure and heat transfer is by only forced
convection, with h=250 W/m2K, what is the maximum operating power?
Chips of width L _ 15 mm on a side are mounted to a substrate that is installed in an enclosurewhose walls and air are maintained at a temperature of Tsur=T∞=25oC. The chips have an emissivity ofε=0.60 and a maximum allowable temperature of Ts=85oC.(a) If heat is rejected from the chips by radiation and natural convection, what is the maximum operatingpower of each chip? The convection coefficient may be approximated as h=11.7 W/m2K.(b) If a fan is used to maintain airflow through the enclosure and heat transfer is by only forcedconvection, with h=250 W/m2K, what is the maximum operating power?
3. An electric immersion heater, 10 mm in diameter and 300 mm long, is rated at 550 W. The
emissivity of the heater is ε = 0.85.
a) If the heater is horizontally positioned in a large tank of water at 20°C, estimate its surface
temperature.
b) If the heater is accidentally operated in air at 20°C, estimate the surface temperature.
Hint: Radiation heat transfer can be neglected in liquids, but not in gases like air.
Chapter 7 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 7 - Consider the following fluids at a film...Ch. 7 - Engine oil at 100C and a velocity of 0.1 m/s flows...Ch. 7 - Consider steady, parallel flow of atmospheric air...Ch. 7 - Consider a liquid metal (Pr1), with free stream...Ch. 7 - Consider the velocity boundary layer profile for...Ch. 7 - Consider a steady, turbulent boundary layer on and...Ch. 7 - Consider flow over a flat plate for which it is...Ch. 7 - A flat plate of width 1 m is maintained at a...Ch. 7 - An electric air heater consists of a horizontal...Ch. 7 - Consider atmospheric air at 25C and a velocity of...
Ch. 7 - Repeat Problem 7.11 for the case when the boundary...Ch. 7 - Consider water at 27°C in parallel flow over an...Ch. 7 - Explain under what conditions the total rate of...Ch. 7 - In fuel cell stacks, it is desirable to operate...Ch. 7 - The roof of a refrigerated truck compartment is of...Ch. 7 - The top surface of a heated compartment consists...Ch. 7 - Calculate the value of the average heat transfer...Ch. 7 - The proposed design for an anemometer to determine...Ch. 7 - Steel (AISI 1010) plates of thickness =6mm and...Ch. 7 - Consider a rectangular fin that is used to cool a...Ch. 7 - The Weather Channel reports that it is a hot,...Ch. 7 - In the production of sheet metals or plastics, it...Ch. 7 - An array of electronic chips is mounted within a...Ch. 7 - A steel strip emerges from the hot roll section of...Ch. 7 - In Problem 7.23. an anemometer design was...Ch. 7 - One hundred electrical components, each...Ch. 7 - The boundary layer associated with parallel flow...Ch. 7 - Forced air at 250C and 10 m/s is used to cool...Ch. 7 - Air at atmospheric pressure and a temperature of...Ch. 7 - Consider a thin, 50mm50mm fuel cell similar to...Ch. 7 - The cover plate of a flat-plate solar collector is...Ch. 7 - An array of 10 silicon chips, each of length...Ch. 7 - A square (10mm10mm) silicon chip is insulated on...Ch. 7 - A circular pipe of 25-mm outside diameter is...Ch. 7 - An L=1-m- long vertical copper tube of inner...Ch. 7 - A long, cylindrical, electrical heating element of...Ch. 7 - Consider the conditions of Problem 7.49, but now...Ch. 7 - Pin fins are to be specified for use in an...Ch. 7 - Prob. 7.52PCh. 7 - Prob. 7.53PCh. 7 - Hot water at 500C is routed from one building in...Ch. 7 - In a manufacturing process, long aluminum rods of...Ch. 7 - Prob. 7.58PCh. 7 - To determine air velocity changes, it is proposed...Ch. 7 - Determine the convection heat loss from both the...Ch. 7 - Prob. 7.63PCh. 7 - Prob. 7.64PCh. 7 - Prob. 7.67PCh. 7 - A thermocouple is inserted into a hot air duct to...Ch. 7 - Consider a sphere with a diameter of 20 mm and a...Ch. 7 - Prob. 7.76PCh. 7 - A spherical, underwater instrument pod used to...Ch. 7 - Worldwide. over a billion solder balls must be...Ch. 7 - Prob. 7.80PCh. 7 - Prob. 7.81PCh. 7 - Consider the plasma spray coating process of...Ch. 7 - Prob. 7.83PCh. 7 - Tissue engineering involves the development of...Ch. 7 - Consider temperature measurement in a gas stream...Ch. 7 - Prob. 7.89PCh. 7 - A preheater involves the use of condensing steam...Ch. 7 - Prob. 7.91PCh. 7 - A tube bank uses an aligned arrangement of...Ch. 7 - A tube bank uses an aligned arrangement of...Ch. 7 - Repeat Problem 7.94, but with NL=7,NT=10, and...Ch. 7 - Heating and cooling with miniature impinging jets...Ch. 7 - A circular transistor of 10-mm diameter is cooled...Ch. 7 - A long rectangular plate of AISI 304 stainless...Ch. 7 - A cryogenic probe is used to treat cancerous skin...Ch. 7 - Prob. 7.103PCh. 7 - Prob. 7.104PCh. 7 - Prob. 7.105PCh. 7 - Consider the packed bed of aluminum spheres...Ch. 7 - Prob. 7.108PCh. 7 - Prob. 7.109PCh. 7 - Prob. 7.111PCh. 7 - Packed beds of spherical panicles can be sintered...Ch. 7 - Prob. 7.114PCh. 7 - Prob. 7.116PCh. 7 - Prob. 7.117PCh. 7 - Prob. 7.118PCh. 7 - Prob. 7.119PCh. 7 - Prob. 7.120PCh. 7 - Dry air at 35°C and a velocity of 20 m/s flows...Ch. 7 - Prob. 7.123PCh. 7 - Benzene, a known carcinogen, has been spilled on...Ch. 7 - Prob. 7.125PCh. 7 - Prob. 7.126PCh. 7 - Condenser cooling water for a power plant is...Ch. 7 - Prob. 7.128PCh. 7 - In a paper-drying process, the paper moves on a...Ch. 7 - Prob. 7.131PCh. 7 - Prob. 7.132PCh. 7 - Prob. 7.133PCh. 7 - Prob. 7.134PCh. 7 - Prob. 7.136PCh. 7 - It has been suggested that heat transfer from a...Ch. 7 - Prob. 7.138PCh. 7 - Cylindrical dry-bulb and wet-bulb thermometers are...Ch. 7 - The thermal pollution problem is associated with...Ch. 7 - Cranberries are harvested by flooding the bogs in...Ch. 7 - A spherical drop of water, 0.5 mm in diameter, is...Ch. 7 - Prob. 7.143PCh. 7 - Prob. 7.144PCh. 7 - Prob. 7.145PCh. 7 - Prob. 7.146PCh. 7 - Prob. 7.147PCh. 7 - Consider an air-conditioning system composed of a...Ch. 7 - Prob. 7.149P
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
Determine the coordinate direction angles of F1. Probs. 2-65/66
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
The expression for the rate at which useful heat is collected per unit area of the collector and also find the ...
Introduction to Heat Transfer
Determine the maximum compression of the spring mounted on car A. Neglect rolling resistance.
Engineering Mechanics: Dynamics (14th Edition)
Check whether the dimensions in the given quantities are correct or not.
Thinking Like an Engineer: An Active Learning Approach (4th Edition)
What parts are included in the vehicle chassis?
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
Fluid with 1040 kg/m3 density is flowing steadily through the rectangular box shown. Given A1 = 0.046 m2, A2 = ...
Fox and McDonald's Introduction to Fluid Mechanics
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
- 5.43 A refrigeration truck is traveling at 130 km/h on a desert highway where the air temperature is . The body of the truck is idealized as a rectangular box 3 m wide, 2.1 m high, and 6 m long, at a surface temperature . Assume that (1) the heat transfer from the front and back of the truck is neglected, (2) the stream does not separate from the surface, and (3) the boundary layer is turbulent over the whole surface. Calculate the required cooling rate of the refrigeration unit.arrow_forwardA tube bank uses an aligned array with 10 mm diameter tubes and ST=SL=60 mm. The arrangement is 10 lines of tubes with 7 tubes in each. Cold water flows inside the tubes and their surface is kept at 30 °C, while the combustion gases flow cross-flow to the bank of tubes, the inlet temperature of the gases is 450 °C and their velocity is 15 m/s. Combustion gases can be approximated as air at 1 atm. Determine: A) The outlet temperature of the combustion gasesB) The heat transfer coefficientC) The amount of heat transferred through the bank of tubesarrow_forwardProblem#6* A preheater involves the use of condensing steam at 100°C on the inside of a bank of tubes to heat air that enters at 1 atmosphere and 15°C. The air moves at 8 m/s in cross flow over the tubes. Each tube is 2 m long and has an outside diameter of 5 mm. The bank consists of 196 tubes in a square, aligned array in which the distance between tube centers is 15 mm. What is the temperature of the air after passing through the tubes. Also, what is the pressure drop associated with the air flow?arrow_forward
- Give me correct answer and solve by hand please I request you give me correct answerarrow_forwardProblem 3 A wet towel (a=75 cm wide, b=1.5 m long) hangs on a cloths line under conditions for which one towel surface receives solar radiation of Qs=900 W/m². Both towel surfaces are exposed to the atmospheric (sky) and ground radiation of Qshy=200 W/m² and Qg=250 W/m², respectively. Under the moderately windy conditions (airflow at a temperature T, = 27 °C, air relative humidity =60%) the convective heat transfer coefficient is o= 20 W/m²-K at both towel surfaces. The wet towel has an emissivity of = 0.96 and the solar absorption coefficient a,=0.65. Determine the towel temperature and the corresponding evaporation rate of moisture from the towel. Assume the air properties at temperature T, = 27 °C.arrow_forwardAt the end of its manufacturing process, a silicon wafer of diameter d= 258 mm , thickness & =1 mm is at an initial temperature of 325 C and is allowed to cool in quiescent, ambient air and large surroundings for which T =T= 25 C, What is the initial rate of cooling by convection (kJ/s) from the Lower surface ONLY (Watts)? 3 Silicon :p= 2330 kg/m , c̟ = 813 J/kg K, k = 87.8 W/m · K. -6 Air: v = 32.15×10 m /s, k = 0.0372 W/m· K, a = 46.8 ×10 0.686, m /s, Pr = Quiescent air T Tsur Silicon wafer D, 8, e, T Select one:arrow_forward
- A long pipe 5 cm in diameter passes through a room and is exposed to air at atmospheric pressure and temperature of 20.C. The pipe surface temperature is 93°C Assuming that the emissivity of the pipe is 0.6 calculate the radiation heat loss per meter of length of pipearrow_forwardThe furnace water walls of a steam generator having a capacity of 9 kg/s, consist of 130 half radiant tubes of 30 mm diameter spaced by 75 mm center distance and 15 m long each, and a temperature of 450°C. If the latent heat of vaporization of the water is 2200 kJ/kg and 25% of the steam latent heat is carried by radiation. For the fuel, emissivity=0.9, sigma=5.67x10-8 W/m2.K4. Determine the temperature of the flue gases at the outlet of the furnace. Select one: a. 1414 °C b. 735 K c. 1141 K d. 1141 °Carrow_forwardFUNDAMENTALS OF CONVECTION Consider a flat plate positioned inside a wind tunnel, and air at 1 atm and 20°C is flowing with a free stream velocity of 60 m/s. What is the minimum length of the plate necessary for the Reynolds number to reach 2x107? If the critical Reynolds number is 5x105, what type of flow regime would the airflow experience at 0.2 m from the leading edge? Please, I need the solution from fundamental concepts of how the heat flow behaves in the system. That it be answered with theory of the subjectarrow_forward
- Consider a flat plate placed inside a wind tunnel, and air at 1 ATM and 20°C is flowing with a free flow velocity of 60 m/s. What is the minimum length of the plate needed for the Reynolds number to reach 2 × 107? If the critical Reynolds number for external flow is 5 × 105, what type of flow regime would the airflow experience at 0.2 m from the leading edge? I need the solution from fundamental concepts of how the heat flow behaves in the systemarrow_forwardSolve it ASAParrow_forwardno previous attempt pleasearrow_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