HEAT+MASS TRANSFER:FUND.+APPL.(LOOSE)
6th Edition
ISBN: 9781260440027
Author: CENGEL
Publisher: MCG
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Chapter 4, Problem 32P
In an experiment, the temperature of a hot gas stream is to be measured by a thermocouple with a spherical junction. Due to the nature of this experiment, the response time of the thermocouple to register 99 percent of the initial temperature difference must be within 5 s. The properties of the thermocouple junction are
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In an experiment, the temperature of a hot gas stream is to be measured by a thermocouple with a spherical junction. Due to the nature of this experiment, the response time of the thermocouple to register 69 percent of the initial temperature difference must be within 5 s. The properties of the thermocouple junction are k = 35 W/m•K, ρ = 8500 kg/m3, and cp = 320 J/kg•K. If the heat transfer coefficient between the thermocouple junction and the gas is 250 W/m2•K, determine the diameter of the junction.
Oil is flowing through a 45 mm inside diameter iron pipe (k=16 W/mK) at 1.2 m/s. The thickness of pipe is 8 mm. It is being heated by steam outside the pipe, and the steam-film coefficient may be taken as 12 kW/m2 oC. At a particular point along the pipe the oil is at 40 oC, its density is 880 kg/m3, its viscosity is 2.1 cP, its thermal conductivity is 0.135 W/moC and its specific heat is 2.17 J/g oC.
a) What is the overall heat transfer coefficient at this point, based on the inside area of the pipe?
b) If the steam temperature is 120oC, what is the heat transfer rate at this point, based on the outside area of the pipe?
c) Calculate the inside and outside wall temperatures of pipe when the steam temperature is 120oC and bulk temperature of oil is 40o
A steam pipe 50 mm diameter and 2.5 m long has been placed horizontally and exposed to still air at 25 degree Celsius. If the pipe wall temperature is 295 degree Celsius, determine the rate of heat loss. At the mean temperature difference of 160 degree Celsius, the thermo-physical properties of air are
k =3.64 * 10 -2 W/m
v =30.09 * 10 -6 m2/
P r =0.68
Β =1/160 + 273 = 2.31 * 10^-3/K
Chapter 4 Solutions
HEAT+MASS TRANSFER:FUND.+APPL.(LOOSE)
Ch. 4 - What is the physical significance of the Biot...Ch. 4 - What is lumped system analysis? When is it...Ch. 4 - In what medium is the lumped system analysis more...Ch. 4 - For which solid is the lumped system analysis more...Ch. 4 - For which kinds of bodies made of the same...Ch. 4 - Consider heat transfer between two identical hot...Ch. 4 - Consider heat transfer between two identical hot...Ch. 4 - Consider a hot baked potato on a plate. The...Ch. 4 - Consider a potato being baked in an oven that is...Ch. 4 - Consider two identical 4-kg pieces of roast beef....
Ch. 4 - Consider a sphere and a cylinder of equal volume...Ch. 4 - Obtain relations for the characteristic lengths of...Ch. 4 - Obtain a relation for the time required for a...Ch. 4 - A brick of 20310257mm in dimension is being burned...Ch. 4 - Prob. 15PCh. 4 - Prob. 16PCh. 4 - Prob. 17PCh. 4 - Metal plates...Ch. 4 - Prob. 19PCh. 4 - Prob. 20PCh. 4 - Prob. 21PCh. 4 - A 6-mm-thick stainless steel strip...Ch. 4 - After heat treatment, the 2-cm-thick metal plates...Ch. 4 - A long copper rod of diameter 2.0 cm is initially...Ch. 4 - Prob. 25PCh. 4 - Steel rods...Ch. 4 - Prob. 27PCh. 4 - Prob. 28PCh. 4 - To warm up some milk for a baby, a mother pours...Ch. 4 - A person is found dead at 5 p.m. in a room whose...Ch. 4 - Prob. 31PCh. 4 - In an experiment, the temperature of a hot gas...Ch. 4 - Prob. 33PCh. 4 - Pulverized coal particles are used in oxy-fuel...Ch. 4 - Oxy-fuel combustion power plants use pulverized...Ch. 4 - Plasma spraying is a process used for coating a...Ch. 4 - Consider a spherical shell satellite with outer...Ch. 4 - Prob. 38PCh. 4 - Prob. 39PCh. 4 - Prob. 40EPCh. 4 - Consider a sphere of diameter 5 cm, a cube of side...Ch. 4 - Prob. 42PCh. 4 - An egg is to be cooked to a certain level of...Ch. 4 - What is an infinitely long cylinder? When is it...Ch. 4 - What is the physical significance of the Fourier...Ch. 4 - Prob. 46CPCh. 4 - Prob. 47CPCh. 4 - The Biot number during a heat transfer process...Ch. 4 - A body at an initial temperature of Ti, is brought...Ch. 4 - Prob. 50PCh. 4 - In a meat processing plant, 2-cm-thick steaks...Ch. 4 - Prob. 52PCh. 4 - Prob. 53PCh. 4 - Prob. 54PCh. 4 - Prob. 55PCh. 4 - Layers of 23-cm-thick meat slabs...Ch. 4 - Prob. 57PCh. 4 - Prob. 58PCh. 4 - Prob. 59PCh. 4 - Prob. 60PCh. 4 - Prob. 61PCh. 4 - Prob. 62EPCh. 4 - Prob. 63PCh. 4 - Prob. 64PCh. 4 - Prob. 65PCh. 4 - Prob. 66PCh. 4 - A 30-cm-diameter, 4-m-high cylindrical column of a...Ch. 4 - Prob. 68PCh. 4 - Prob. 69PCh. 4 - Prob. 70PCh. 4 - For heat transfer purposes, an egg can be...Ch. 4 - Citrus fruits are very susceptible to cold...Ch. 4 - Chickens with an average mass of 1.7 kg...Ch. 4 - Prob. 74PCh. 4 - Prob. 75PCh. 4 - Prob. 76PCh. 4 - Oranges of 2.5-in-diameter...Ch. 4 - Prob. 78PCh. 4 - Prob. 79PCh. 4 - Prob. 80PCh. 4 - Prob. 81PCh. 4 - A 9-cm-diameter potato...Ch. 4 - In Betty Crocker s Cookbook, it is stated that it...Ch. 4 - Prob. 84PCh. 4 - Under what conditions can a plane wall be treated...Ch. 4 - What is a semi-infinite medium? Give examples of...Ch. 4 - Consider a hot semi-infinite solid at an initial...Ch. 4 - Prob. 88EPCh. 4 - Prob. 89PCh. 4 - In areas where the air temperature remains below...Ch. 4 - Prob. 91PCh. 4 - A highway made of asphalt is initially at a...Ch. 4 - A thick aluminum block initially at 20C is...Ch. 4 - Prob. 94PCh. 4 - A thick wall made of refractory bricks...Ch. 4 - Prob. 96PCh. 4 - Prob. 97PCh. 4 - A thick wood slab (k=0.17W/m.K,=1.2810-7m2/s) and...Ch. 4 - Prob. 99PCh. 4 - Prob. 100PCh. 4 - Prob. 101PCh. 4 - Prob. 102PCh. 4 - Prob. 103PCh. 4 - Prob. 104PCh. 4 - Prob. 105PCh. 4 - A barefooted person whose feet are at 32C steps on...Ch. 4 - What is the product solution method? How is it...Ch. 4 - How is the product solution used to determine the...Ch. 4 - Prob. 109CPCh. 4 - Consider a short cylinder whose top and bottom...Ch. 4 - Prob. 111PCh. 4 - Prob. 112PCh. 4 - Prob. 113PCh. 4 - A hot dog can be considered to be a cylinder 5 in...Ch. 4 - Prob. 115PCh. 4 - Prob. 116PCh. 4 - A 2-cm-high cylindrical ice block...Ch. 4 - Prob. 118PCh. 4 - Prob. 119PCh. 4 - Prob. 120PCh. 4 - Prob. 121PCh. 4 - Prob. 122PCh. 4 - Prob. 123PCh. 4 - Prob. 124CPCh. 4 - How does refrigeration prevent or delay the...Ch. 4 - What are the environmental factors that affect the...Ch. 4 - What is the effect of cooking on the...Ch. 4 - Prob. 128CPCh. 4 - Prob. 129CPCh. 4 - Prob. 130CPCh. 4 - Prob. 131CPCh. 4 - How does the rate of freezing affect the...Ch. 4 - Prob. 133CPCh. 4 - Prob. 134CPCh. 4 - Prob. 135CPCh. 4 - Prob. 136CPCh. 4 - Prob. 137CPCh. 4 - Prob. 138PCh. 4 - Chickens with an average mass of 2.2 kg and...Ch. 4 - Prob. 140EPCh. 4 - Prob. 141PCh. 4 - Prob. 142PCh. 4 - A long roll of 2-m-wide and 0.5-cm-thick 1-Mn...Ch. 4 - Prob. 144PCh. 4 - Prob. 145PCh. 4 - Prob. 146PCh. 4 - During a picnic on a hot summer day, the only...Ch. 4 - Two metal rods are being heated in an oven with...Ch. 4 - Stainless steel ball bearings...Ch. 4 - Prob. 150PCh. 4 - Prob. 151PCh. 4 - In Betty crockers Cookbook, it is stated that it...Ch. 4 - A watermelon initially at 35C is to be cooled by...Ch. 4 - Prob. 154PCh. 4 - Prob. 155PCh. 4 - Prob. 156PCh. 4 - Prob. 157PCh. 4 - Prob. 158PCh. 4 - Prob. 159PCh. 4 - Prob. 160PCh. 4 - Prob. 161PCh. 4 - Prob. 162PCh. 4 - Prob. 163PCh. 4 - Lumped system analysis of transient heat...Ch. 4 - Prob. 165PCh. 4 - Prob. 166PCh. 4 - An 18-cm-long, 16-cm-wide, and 12-cm-high hot iron...Ch. 4 - Prob. 168PCh. 4 - Prob. 169PCh. 4 - Prob. 170PCh. 4 - Prob. 171PCh. 4 - Prob. 172PCh. 4 - A long 18-cm-diameter bar made of hardwood...Ch. 4 - Consider a 7.6-cm-long and 3-cm-diameter...Ch. 4 - Consider a 7.6-cm-diameter cylindrical lamb meat...Ch. 4 - Prob. 176PCh. 4 - A small chicken (k=0.45W/m.K,=0.1510-6m2/s) and...Ch. 4 - A potato may be approximated as a 5.7-cm-diameter...Ch. 4 - When water, as in a pond or lake, is heated by...Ch. 4 - A large chunk of tissue at 35C with a thermal...Ch. 4 - Prob. 181PCh. 4 - Citrus trees are very susceptible to cold weather,...
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