HEAT+MASS TRANSFER:FUND..(LL)-W/CONNECT
6th Edition
ISBN: 9781260699326
Author: CENGEL
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 3, Problem 105CP
To determine
The thickness of insulation for windy and calm days.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
You are working as an engineer in a bearing systems design company. The flow of
lubricant inside a hydrodynamic bearing (p = 0.001 kg m-1 s-1) can be approximated
as a parallel, steady, two-dimensional, incompressible flow between two parallel plates.
The top plate, representing the moving part of the bearing, travels at a constant speed,
U, while the bottom plate remains stationary (Figure Q1). The plates are separated by
a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By
applying the above approximations to the Navier-Stokes equations and assuming that
end effects can be neglected, the horizontal velocity profile can be shown to be
y = +h
I
2h = 1 cm
x1
y = -h
u(y)
1 dP
2μ dx
-y² + Ay + B
moving plate
stationary plate
U
2
I2
L = 10 cm
Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm,
into the page.
Question 1
You are working as an engineer in a bearing systems design company. The flow of
lubricant inside a hydrodynamic bearing (µ = 0.001 kg m¯¹ s¯¹) can be approximated
as a parallel, steady, two-dimensional, incompressible flow between two parallel plates.
The top plate, representing the moving part of the bearing, travels at a constant speed,
U, while the bottom plate remains stationary (Figure Q1). The plates are separated by
a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By
applying the above approximations to the Navier-Stokes equations and assuming that
end effects can be neglected, the horizontal velocity profile can be shown to be
1 dP
u(y)
=
2μ dx
-y² + Ay + B
y= +h
Ꮖ
2h=1 cm
1
x1
y = −h
moving plate
stationary plate
2
X2
L = 10 cm
Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm,
into the page.
(a) By considering the appropriate boundary conditions, show that the constants take
the following forms:
U
U
1 dP
A =…
Question 2
You are an engineer working in the propulsion team for a supersonic civil transport
aircraft driven by a turbojet engine, where you have oversight of the design for the
engine intake and the exhaust nozzle, indicated in Figure Q2a. The turbojet engine can
operate when provided with air flow in the Mach number range, 0.60 to 0.80. You are
asked to analyse a condition where the aircraft is flying at 472 m/s at an altitude of
14,000 m. For all parts of the question, you can assume that the flow path of air through
the engine has a circular cross section.
(a)
← intake
normal
shock
472 m/s
A B
(b)
50 m/s
H
472 m/s
B
engine
altitude: 14,000 m
exhaust nozzle
E
F
exit to
atmosphere
diameter: DE = 0.30 m
E
F
diameter: DF = 0.66 m
Figure Q2: Propulsion system for a supersonic aircraft.
a) When the aircraft is at an altitude of 14,000 m, use the International Standard
Atmosphere in the Module Data Book to state the local air pressure and tempera-
ture. Thus show that the aircraft speed…
Chapter 3 Solutions
HEAT+MASS TRANSFER:FUND..(LL)-W/CONNECT
Ch. 3 - Consider heat conduction through a wall of...Ch. 3 - Consider heat conduction through a plane wall....Ch. 3 - What does the thermal resistance of a medium...Ch. 3 - Can we defme the convection resistance for a unit...Ch. 3 - Consider steady heat transfer through the wall of...Ch. 3 - How is the combined heat transfer coefficient...Ch. 3 - Why are the convection and the radiation...Ch. 3 - Consider steady one-dimensional heat transfer...Ch. 3 - Someone comments that a microwave oven can be...Ch. 3 - Consider two cold canned drinks, one wrapped in a...
Ch. 3 - The bottom of a pan is made of a 4-mm-thick...Ch. 3 - Consider a surface of area A at which the...Ch. 3 - How does the thermal resistance network associated...Ch. 3 - Consider steady one-dimensional heat transfer...Ch. 3 - Consider a window glass consisting of two...Ch. 3 - Prob. 16PCh. 3 - Consider a person standing in a room at 20C with...Ch. 3 - Consider an electrically heated brick house...Ch. 3 - A12-cm18-cm circuit board houses on its surface...Ch. 3 - Water is boiling in a 25-cm-diameter aluminum pan...Ch. 3 - A cylindrical resistor element on a circuit board...Ch. 3 - Prob. 22PCh. 3 - A1.0m1.5m double-pane window consists of two...Ch. 3 - Prob. 24PCh. 3 - Prob. 25PCh. 3 - Prob. 26PCh. 3 - Prob. 27PCh. 3 - Prob. 28EPCh. 3 - To defog the rear window of an automobile, a very...Ch. 3 - A transparent film is to be bonded onto the top...Ch. 3 - To defrost ice accumulated on the outer surface of...Ch. 3 - Prob. 32PCh. 3 - Prob. 33PCh. 3 - Prob. 34PCh. 3 - Prob. 35PCh. 3 - Heat is to be conducted along a circuit board that...Ch. 3 - Prob. 37EPCh. 3 - Consider a house that has a 10m20-m base and a...Ch. 3 - Prob. 39EPCh. 3 - Prob. 40PCh. 3 - Prob. 41PCh. 3 - Prob. 42PCh. 3 - Prob. 43PCh. 3 - What is thermal contact resistance? How is it...Ch. 3 - Will the thermal contact resistance be greater for...Ch. 3 - Explain how the thermal contact resistance can be...Ch. 3 - A waII consists of two layers of insulation...Ch. 3 - Prob. 48CPCh. 3 - Consider two surfaces pressed against each other....Ch. 3 - Prob. 50PCh. 3 - Two 5-cm-diameter, 15-cm-long aluminum bars...Ch. 3 - Prob. 52PCh. 3 - Two identical aluminum plates with thickness of 30...Ch. 3 - A tvolayer wall is made of two metal plates, with...Ch. 3 - Prob. 55PCh. 3 - An aluminum plate and a stainless steel plate are...Ch. 3 - Prob. 57PCh. 3 - Prob. 58PCh. 3 - Prob. 59PCh. 3 - Prob. 60PCh. 3 - Prob. 61PCh. 3 - What are the two approaches used in the...Ch. 3 - The thermal resistance networks can also be used...Ch. 3 - When plotting the thermal resistance network...Ch. 3 - A 10-cm-thick vall is to be constructed with...Ch. 3 - Prob. 66EPCh. 3 - Prob. 67PCh. 3 - Prob. 68PCh. 3 - Prob. 69PCh. 3 - Prob. 70PCh. 3 - Prob. 71PCh. 3 - Prob. 72PCh. 3 - A 12-m-long and 5-m-high wall is constructed of...Ch. 3 - Prob. 74EPCh. 3 - Prob. 75PCh. 3 - Prob. 76PCh. 3 - Prob. 77PCh. 3 - What is an infinitely long cylinder? When is it...Ch. 3 - Can the thermal resistance concept be used for a...Ch. 3 - Consider a short cylinder whose top and bottom...Ch. 3 - Prob. 81PCh. 3 - Prob. 82PCh. 3 - Prob. 83PCh. 3 - Superheated steam at an average temperature 20C is...Ch. 3 - Prob. 85PCh. 3 - Prob. 86PCh. 3 - Prob. 87EPCh. 3 - Prob. 88EPCh. 3 - Prob. 89EPCh. 3 - Prob. 90PCh. 3 - Prob. 91PCh. 3 - Prob. 92PCh. 3 - Prob. 93EPCh. 3 - Prob. 94PCh. 3 - Prob. 95PCh. 3 - Prob. 96PCh. 3 - Liquid hydrogen is flowing through an insulated...Ch. 3 - Exposure to high concentrations of gaseous ammonia...Ch. 3 - A mixture of chemicals is flowing in a pipe...Ch. 3 - Ice slurry is being transported in a pipe...Ch. 3 - Prob. 101PCh. 3 - Prob. 102PCh. 3 - Prob. 103PCh. 3 - What is the critical radius of insulation? How is...Ch. 3 - Prob. 105CPCh. 3 - Prob. 106CPCh. 3 - Prob. 107CPCh. 3 - A pipe is insulated such that the outer radius of...Ch. 3 - A 0.083-in-diameter electrical wire at 90F is...Ch. 3 - Repeat Prob. 3-109E, assuming a thermal contact...Ch. 3 - Prob. 111PCh. 3 - Prob. 112PCh. 3 - Hot air is to be cooled as it is forced to flow...Ch. 3 - Prob. 114CPCh. 3 - Prob. 115CPCh. 3 - The fins attached to a surface are determined to...Ch. 3 - Explain how the fins enhance heat transfer from a...Ch. 3 - How does the overall effectiveness of a finned...Ch. 3 - Hot water is to be cooled as it flows through the...Ch. 3 - Consider two finned surfaces that are identical...Ch. 3 - The heat transfer surface area of a fin is equal...Ch. 3 - Does the (a) efficiency and (b) effectiveness of a...Ch. 3 - Two pin fins are identical, except that the...Ch. 3 - Two plate fins of constant rectangular cross...Ch. 3 - Two finned surfaces are identical, except that the...Ch. 3 - Obtain a relation for the fin efficiency for a fin...Ch. 3 - Prob. 127PCh. 3 - Consider a very long rectangular fin attached to a...Ch. 3 - Prob. 129PCh. 3 - Prob. 130PCh. 3 - Prob. 131PCh. 3 - Prob. 132PCh. 3 - Prob. 133EPCh. 3 - Prob. 134EPCh. 3 - Prob. 135PCh. 3 - Prob. 136PCh. 3 - Prob. 137PCh. 3 - Prob. 138PCh. 3 - Prob. 139PCh. 3 - Prob. 140PCh. 3 - Prob. 141PCh. 3 - Prob. 142PCh. 3 - Prob. 143PCh. 3 - Prob. 144PCh. 3 - Prob. 145PCh. 3 - Prob. 146PCh. 3 - The human body is adaptable to extreme climatic...Ch. 3 - Consider the conditions of Example 3-14 in the...Ch. 3 - Consider the conditions of Example 3-14 in the...Ch. 3 - Prob. 150PCh. 3 - What is a conduction shape factor? How is it...Ch. 3 - What is the value of conduction shape factors in...Ch. 3 - Prob. 153PCh. 3 - A thin-walled cylindrical container is placed...Ch. 3 - Prob. 155PCh. 3 - Prob. 156PCh. 3 - Prob. 157PCh. 3 - Prob. 158EPCh. 3 - Prob. 159PCh. 3 - Prob. 160PCh. 3 - Prob. 161PCh. 3 - Prob. 162PCh. 3 - Prob. 163PCh. 3 - Prob. 164PCh. 3 - Consider a house with a flat roof whose outer...Ch. 3 - Prob. 166PCh. 3 - Radioactive material, stored in a spherical vessel...Ch. 3 - What is the R-value of a wall? How does it differ...Ch. 3 - What is effective emissivity for a plane-parallel...Ch. 3 - Prob. 170CPCh. 3 - What is a radiant barrier? What kinds of materials...Ch. 3 - Consider a house whose attic space is ventilated...Ch. 3 - Prob. 173PCh. 3 - Prob. 174PCh. 3 - Prob. 175PCh. 3 - Prob. 176PCh. 3 - Prob. 177PCh. 3 - Prob. 178PCh. 3 - Determine the winter R-value and the U-factor of a...Ch. 3 - The overall heat transfer coefficient (the...Ch. 3 - Prob. 181EPCh. 3 - Determine the summer and winter R-values. in m2 ....Ch. 3 - The overall heat transfer coefficient of a wall is...Ch. 3 - Two homes are identical, except that the walls of...Ch. 3 - Prob. 185PCh. 3 - Consider two identical people each generating 60 V...Ch. 3 - Cold conditioned air at 12C is flowing inside a...Ch. 3 - Hot water is flowing at an average velocity of 1.5...Ch. 3 - Prob. 189PCh. 3 - Prob. 190PCh. 3 - Prob. 191PCh. 3 - Prob. 192PCh. 3 - Prob. 193PCh. 3 - Prob. 194PCh. 3 - Prob. 195PCh. 3 - Prob. 196PCh. 3 - Prob. 197PCh. 3 - A total of 10 rectangular aluminum fins...Ch. 3 - Prob. 199PCh. 3 - A plane wall surface at 200C is to be cooled with...Ch. 3 - Prob. 201PCh. 3 - Prob. 202PCh. 3 - Prob. 203PCh. 3 - Prob. 204PCh. 3 - A 0.6-rn-diameter, 1.9-rn-long cylindrical tank...Ch. 3 - Prob. 206PCh. 3 - Prob. 207PCh. 3 - A thin-walled spherical tank is buried in the...Ch. 3 - Heat is lost at a rate of 275 W per m2 area of a 1...Ch. 3 - Prob. 210PCh. 3 - Heat is generated steadily in a 3-cm-diameter...Ch. 3 - Prob. 212PCh. 3 - Prob. 213PCh. 3 - Prob. 214PCh. 3 - Prob. 215PCh. 3 - Prob. 216PCh. 3 - Consider two walls. A and B, with the same surface...Ch. 3 - Prob. 218PCh. 3 - A room at 20C air temperature is losing heat to...Ch. 3 - Prob. 220PCh. 3 - A 1-cm-diameter, 30cm-long fin made of aluminum...Ch. 3 - A hot surface at 80C in air at 20C is to be cooled...Ch. 3 - A cylindrical pin fin of diameter 0.6 cm and...Ch. 3 - A 3-cm-long. 2-nuti x 2-mm rectangular...Ch. 3 - Two finned surfaces with long fins are identical,...Ch. 3 - A 20-cm-diameter hot sphere at 120C is buried in...Ch. 3 - A 25-cm-diameter, 2.4-rn-long vertical cylinder...Ch. 3 - Prob. 228PCh. 3 - The walls of a food storage facility are made of a...Ch. 3 - The equivalent thermal resistance for the thermal...Ch. 3 - Prob. 231PCh. 3 - Prob. 232PCh. 3 - Prob. 233PCh. 3 - The fin efficiency is defined as the ratio of the...Ch. 3 - Prob. 235PCh. 3 - In the United States, building insulation is...Ch. 3 - Prob. 237PCh. 3 - A plane brick wall (k=0.7W/m.K) and is 10 cm...Ch. 3 - The temperature in deep space is close to absolute...Ch. 3 - In the design of electronic components, it is...Ch. 3 - Using cylindrical samples of the same material,...Ch. 3 - Find out about the wall construction of the cabins...Ch. 3 - Prob. 243PCh. 3 - A house with 200-m2 floor space is to be heated...
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
- يكا - put 96** I need a detailed drawing with explanation or in wake, and the top edge of im below the free surface of the water. Determine the hydrothed if hydrostatic on the Plot the displacement diagram for a cam with roller follower of diameter 10 mm. The required motion is as follows; 1- Rising 60 mm in 135° with uniform acceleration and retardation motion. 2- Dwell 90° 3- Falling 60 mm for 135° with Uniform acceleration-retardation motion. Then design the cam profile to give the above displacement diagram if the minimum circle diameter of the cam is 50 mm. =--20125 7357 750 X 2.01arrow_forwardYou are working as an engineer in a bearing systems design company. The flow of lubricant inside a hydrodynamic bearing (µ = 0.001 kg m¯¹ s¯¹) can be approximated as a parallel, steady, two-dimensional, incompressible flow between two parallel plates. The top plate, representing the moving part of the bearing, travels at a constant speed, U, while the bottom plate remains stationary (Figure Q1). The plates are separated by a distance of 2h = 1 cm and are W = 20 cm wide. Their length is L = 10 cm. By applying the above approximations to the Navier-Stokes equations and assuming that end effects can be neglected, the horizontal velocity profile can be shown to be U y = +h У 2h = 1 cm 1 x1 y=-h u(y) = 1 dP 2μ dx -y² + Ay + B moving plate - U stationary plate 2 I2 L = 10 cm Figure Q1: Flow in a hydrodynamic bearing. The plates extend a width, W = 20 cm, into the page. (a) By considering the appropriate boundary conditions, show that the constants take the following forms: A = U 2h U 1 dP…arrow_forwardQuestion 2 You are an engineer working in the propulsion team for a supersonic civil transport aircraft driven by a turbojet engine, where you have oversight of the design for the engine intake and the exhaust nozzle, indicated in Figure Q2a. The turbojet engine can operate when provided with air flow in the Mach number range, 0.60 to 0.80. You are asked to analyse a condition where the aircraft is flying at 472 m/s at an altitude of 14,000 m. For all parts of the question, you can assume that the flow path of air through the engine has a circular cross section. (a) normal shock 472 m/s A B (b) intake engine altitude: 14,000 m D exhaust nozzle→ exit to atmosphere 472 m/s 50 m/s B diameter: DE = 0.30 m EX diameter: DF = 0.66 m Figure Q2: Propulsion system for a supersonic aircraft. F a) When the aircraft is at an altitude of 14,000 m, use the International Standard Atmosphere in the Module Data Book to state the local air pressure and tempera- ture. Thus show that the aircraft speed of…arrow_forward
- given below: A rectangular wing with wing twist yields the spanwise circulation distribution kbV1 roy) = kbv. (2) where k is a constant, b is the span length and V. is the free-stream velocity. The wing has an aspect ratio of 4. For all wing sections, the lift curve slope (ag) is 2 and the zero-lift angle of attack (a=0) is 0. a. Derive expressions for the downwash (w) and induced angle of attack a distributions along the span. b. Derive an expression for the induced drag coefficient. c. Calculate the span efficiency factor. d. Calculate the value of k if the wing has a washout and the difference between the geometric angles of attack of the root (y = 0) and the tip (y = tb/2) is: a(y = 0) a(y = ±b/2) = /18 Hint: Use the coordinate transformation y = cos (0)arrow_forward۳/۱ العنوان O не شكا +91x PU + 96852 A heavy car plunges into a lake during an accident and lands at the bottom of the lake on its wheels as shown in figure. The door is 1.2 m high and I m wide, and the top edge of Deine the hadrostatic force on the Plot the displacement diagram for a cam with roller follower of diameter 10 mm. The required motion is as follows; 1- Rising 60 mm in 135° with uniform acceleration and retardation motion. 2- Dwell 90° 3- Falling 60 mm for 135° with Uniform acceleration-retardation motion. Then design the cam profile to give the above displacement diagram if the minimum circle diameter of the cam is 50 mm. = -20125 750 x2.01arrow_forwardPlot the displacement diagram for a cam with roller follower of diameter 10 mm. The required motion is as follows; 1- Rising 60 mm in 135° with uniform acceleration and retardation motion. 2- Dwell 90° 3- Falling 60 mm for 135° with Uniform acceleration-retardation motion. Then design the cam profile to give the above displacement diagram if the minimum circle diameter of the cam is 50 mm.arrow_forward
- Q1/ A vertical, circular gate with water on one side as shown. Determine the total resultant force acting on the gate and the location of the center of pressure, use water specific weight 9.81 kN/m³ 1 m 4 marrow_forwardI need handwritten solution with sketches for eacharrow_forwardGiven answers to be: i) 14.65 kN; 6.16 kN; 8.46 kN ii) 8.63 kN; 9.88 kN iii) Bearing 6315 for B1 & B2, or Bearing 6215 for B1arrow_forward
- (b) A steel 'hot rolled structural hollow section' column of length 5.75 m, has the cross-section shown in Figure Q.5(b) and supports a load of 750 kN. During service, it is subjected to axial compression loading where one end of the column is effectively restrained in position and direction (fixed) and the other is effectively held in position but not in direction (pinned). i) Given that the steel has a design strength of 275 MN/m², determine the load factor for the structural member based upon the BS5950 design approach using Datasheet Q.5(b). [11] ii) Determine the axial load that can be supported by the column using the Rankine-Gordon formula, given that the yield strength of the material is 280 MN/m² and the constant *a* is 1/30000. [6] 300 600 2-300 mm wide x 5 mm thick plates. Figure Q.5(b) L=5.75m Pinned Fixedarrow_forwardHelp ارجو مساعدتي في حل هذا السؤالarrow_forwardHelp ارجو مساعدتي في حل هذا السؤالarrow_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
Understanding Conduction and the Heat Equation; Author: The Efficient Engineer;https://www.youtube.com/watch?v=6jQsLAqrZGQ;License: Standard youtube license