HEAT+MASS TRANSFER:FUND.+APPL.
6th Edition
ISBN: 9780073398198
Author: CENGEL
Publisher: RENT MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 1, Problem 128P
An engine block with a surface area measured to be 0.95 m2 generates a power output of 50 kW with a net engine efficiency of 35 percent. The engine block operates inside a compartment at
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Consider a person standing in a breezy room at 20°C. Determine the total rate of heat transfer from this person if the exposed surface area and the average outer surface temperature of the person are 1.6 m2 and 29°C, respectively, and the convection heat transfer coefficient is 6 W/m2 ·°C (Fig. 2–75).
An engine block with a surface area measured to be 0.95 m2 generates a power output of 50 kW with a net engine efficiency of 35%. The engine block operates inside a compartment at 157°C and the average convection heat transfer coefficient is 50 W/m2·K. If convection is the only heat transfer mechanism occurring, determine the engine block surface temperature.
For heat transfer purposes, a standing man can be modeled as a 30-cm-diameter, 175-cm-long vertical cylinder with both the top and bottom surfaces insulated and with the side surface at an average temperature of 34°C. For a convection heat transfer coefficient of 10 W/m2 ·°C, determine the rate of heat loss from this man by convection in an environment at 20°C.
Chapter 1 Solutions
HEAT+MASS TRANSFER:FUND.+APPL.
Ch. 1 - How does the science of heat transfer differ from...Ch. 1 - What is the driving force for (a) heat transfer,...Ch. 1 - How do rating problems in heat transfer differ...Ch. 1 - What is the difference between the analytical and...Ch. 1 - What is the importance of modeling in engineering?...Ch. 1 - When modeling an engineering process, how is the...Ch. 1 - On a hot summer day, a student turns his fan on...Ch. 1 - Consider two identical rooms, one with a...Ch. 1 - Prob. 9CPCh. 1 - Prob. 10CP
Ch. 1 - Prob. 11CPCh. 1 - An ideal gas is heated from 50C to 80C (a) at...Ch. 1 - What is heat flux? How is it related to the heat...Ch. 1 - What are the mechanisms of energy transfer to a...Ch. 1 - A logic chip used in a computer dissipates 3 W of...Ch. 1 - Consider a 150-W incandescent lamp. The filament...Ch. 1 - A 15-cm-diameter aluminum ball is to be heated...Ch. 1 - A 60-gallon water heated is initially filled with...Ch. 1 - Prob. 19PCh. 1 - Prob. 20PCh. 1 - Prob. 21PCh. 1 - Prob. 22PCh. 1 - Prob. 23PCh. 1 - Prob. 24PCh. 1 - Prob. 25PCh. 1 - Prob. 26PCh. 1 - A 5-m6-m8-m room is to be heated by an electrical...Ch. 1 - Prob. 28PCh. 1 - Air enters the duct of an air-conditioning system...Ch. 1 - Prob. 30PCh. 1 - Define thermal conductivity, and explain its...Ch. 1 - Which is a better heat conductor, diamond or...Ch. 1 - How do the thermal conductivity of gases and...Ch. 1 - Why is the thermal conductivity of superinsulation...Ch. 1 - Why do we characterize the heat conduction ability...Ch. 1 - What are the mechanisms of heat transfer? How are...Ch. 1 - Write down the expression for the physical laws...Ch. 1 - How does heat conduction differ from convection?Ch. 1 - Does any of the energy of the sun reach the earth...Ch. 1 - How does forced convection differ from natural...Ch. 1 - What is the physical mechanism of heat conduction...Ch. 1 - Consider heat transfer a windowless wall of house...Ch. 1 - Consider heat loss through two walls of house on a...Ch. 1 - Consider two houses that are identical except that...Ch. 1 - Consider two walls of a house that are identical...Ch. 1 - Define emissivity and absorptivity. What is...Ch. 1 - What is a blackbody? How do real bodies differ...Ch. 1 - A wood slab with a thickness 0.05 m is subjected...Ch. 1 - Prob. 49PCh. 1 - Prob. 50EPCh. 1 - The inner and outer surfaces of a 0.5-cm thick...Ch. 1 - Prob. 52PCh. 1 - Prob. 53PCh. 1 - The north wall of an electrically heated home is...Ch. 1 - Prob. 55PCh. 1 - Prob. 56PCh. 1 - Prob. 57PCh. 1 - A concreate wall a surface area of 20 m2 and a...Ch. 1 - Prob. 59PCh. 1 - Prob. 60PCh. 1 - Prob. 61PCh. 1 - Prob. 62EPCh. 1 - Air at 20C with a convection heat transfer...Ch. 1 - Prob. 64PCh. 1 - Prob. 65PCh. 1 - Prob. 66PCh. 1 - Prob. 67PCh. 1 - Prob. 68PCh. 1 - Prob. 69PCh. 1 - Prob. 70PCh. 1 - Prob. 71PCh. 1 - Prob. 72EPCh. 1 - Prob. 73PCh. 1 - Prob. 74PCh. 1 - Prob. 75PCh. 1 - Prob. 76PCh. 1 - Using the conversion factors between W and Btu/h,...Ch. 1 - The outer surface of a spacecraft in space has an...Ch. 1 - Consider a person whose expose surface are is 1.7...Ch. 1 - Prob. 80PCh. 1 - Two surfaces, one highly polished and the other...Ch. 1 - A spherical interplanetary probe with a diameter...Ch. 1 - Prob. 83PCh. 1 - Can all three modes of heat transfer occur...Ch. 1 - Can a medium involve (a) conduction and...Ch. 1 - The deep human body temperature of a healthy...Ch. 1 - We often turn the fan on in summer to help us...Ch. 1 - Prob. 88PCh. 1 - Prob. 89PCh. 1 - Prob. 90PCh. 1 - An electronic package with a surface area of 1 m2...Ch. 1 - Consider steady heat transfer between two large...Ch. 1 - Prob. 93PCh. 1 - Prob. 94PCh. 1 - A 2-in-diameter spherical ball whose surface is...Ch. 1 - Prob. 96PCh. 1 - Prob. 97PCh. 1 - A 3-m-internal-diameter spherical tank made of...Ch. 1 - Prob. 99PCh. 1 - Solar radiation is incident on a 5-m2 solar...Ch. 1 - Prob. 101PCh. 1 - Prob. 102PCh. 1 - Prob. 103EPCh. 1 - An AISI 304 stainless steel sheet is going through...Ch. 1 - Prob. 105PCh. 1 - Prob. 106PCh. 1 - Prob. 107PCh. 1 - Prob. 108CPCh. 1 - Prob. 109PCh. 1 - Prob. 110PCh. 1 - Prob. 111PCh. 1 - Prob. 112PCh. 1 - Prob. 113CPCh. 1 - Why is the metabolic rate of women, in general,...Ch. 1 - What is asymmetric thermal radiation How does it...Ch. 1 - How do (a) draft and (b) cold floor surfaces cause...Ch. 1 - Prob. 117CPCh. 1 - Why is it necessary to ventilate buildings? What...Ch. 1 - Consider a house in Atlanta, Georgia, that is...Ch. 1 - Prob. 120PCh. 1 - A 4m5m6m and room is to be heated by one ton (1000...Ch. 1 - Engine valves (cp=440J/kg.Kandp=7840kg/m3) are to...Ch. 1 - Prob. 123PCh. 1 - Prob. 124PCh. 1 - A 0.3 -cm-thick, 12-cm-high, and 18-cm-long...Ch. 1 - A 40-cm-long, 800-W electric resistance heating...Ch. 1 - It is well known that wind makes the cold air feel...Ch. 1 - An engine block with a surface area measured to be...Ch. 1 - Prob. 129PCh. 1 - Prob. 130PCh. 1 - Prob. 131PCh. 1 - Consider a person standing in a room maintained at...Ch. 1 - Prob. 133PCh. 1 - Prob. 134PCh. 1 - Prob. 135PCh. 1 - Prob. 136PCh. 1 - Prob. 137PCh. 1 - Prob. 138PCh. 1 - Prob. 139PCh. 1 - Prob. 140PCh. 1 - Prob. 141PCh. 1 - Prob. 142PCh. 1 - A 2-kW electric resistance heater submerged in...Ch. 1 - Prob. 144PCh. 1 - A cold bottled drink (m=2.5kg,cp=4200J/kg.K) at...Ch. 1 - Prob. 146PCh. 1 - Air enters a 12-m-long, 7-cm-diameter pipe at 50oC...Ch. 1 - Prob. 148PCh. 1 - Steady heat conduction occurs through a...Ch. 1 - Heat is lost through a brick wall (k=0.72W/m.K),...Ch. 1 - Prob. 151PCh. 1 - A 40-cm-long, 0.4-cm-diameter electric resistance...Ch. 1 - Prob. 153PCh. 1 - Prob. 154PCh. 1 - Over 90 percent of the energy dissipated by an...Ch. 1 - On a still, cleat night, the sky appears to be a...Ch. 1 - Prob. 157PCh. 1 - Prob. 158PCh. 1 - A persons head can be approximated as a...Ch. 1 - A person standing in a room loses heat to the air...Ch. 1 - Write an essay on how microwave ovens work, and...Ch. 1 - Using information form the utility bill for the...Ch. 1 - It is well know that at the same outdoor air...
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
- Heat is transferred at a rate of 0.1 kW through glass wool insulation (density=100kg/m3) with a 5-cm thickness and 2-m2 area. If the hot surface is at 70C, determine the temperature of the cooler surface.arrow_forwardA cooling system is to be designed for a food storage warehouse for keeping perishable foods cool prior to transportation to grocery stores. The warehouse has an effective surface area of 1860 m2 exposed to an ambient air temperature of 32C. The warehouse wall insulation (k=0.17W/(mK)) is 7.5 cm thick. Determine the rate at which heat must be removed (W) from the warehouse to maintain the food at 4C.arrow_forward2.38 The addition of aluminum fins has been suggested to increase the rate of heat dissipation from one side of an electronic device 1 m wide and 1 m tall. The fins are to be rectangular in cross section, 2.5 cm long and 0.25 cm thick, as shown in the figure. There are to be 100 fins per meter. The convection heat transfer coefficient, both for the wall and the fins, is estimated to be K. With this information determine the percent increase in the rate of heat transfer of the finned wall compared to the bare wall.arrow_forward
- 3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer coefficient on one side is and on the other side is . If the temperature of both streams is suddenly changed from 38°C to 93°C, determine how long it takes for the copper plate to reach a temperature of 82°C.arrow_forwardany relationship between inlet, outlet diameter and Effectiveness in heat transfer? How outlet and inlet diameter effects on Effectiveness?arrow_forwardA 1000-W iron is left on the iron board with its base exposed to the air at 20°C. The convection heat transfer coefficient between the base surface and the surrounding air is 35 W/m2. C. If the base has an emissivity of 0.6 and a surface area of 0.02 m2, determine the temperature of the base of the iron.arrow_forward
- 1.)For heat transfer purposes, a standing man can be modeled as a 34.17-cm-diameter, 173.37-cm-long vertical cylinder with both the top and bottom surfaces insulated and with the side surface at an average temperature of 34.46°C. For a convection heat transfer coefficient of 14.33 W/m2 · °C, determine the rate of heat loss from this man by convection in an environment at 20.36°C. 2.)Consider a 1,499.74-kg car cruising at constant speed of 73.89 km/h. Now the car starts to pass another car, by accelerating to 111.73 km/h in 5.84 s. Determine the additional power needed to achieve this acceleration.arrow_forward1. A 1000-W iron is left on the iron board with its base exposed to the air at 20°C. The convection heat transfer coefficient between the base surface and the surrounding air is 35 W/m². °C. If the base has an emissivity of 0.6 and a surface area of 0.02 m², determine the temperature of the base of the iron. 2. The inner and outer surfaces of a 5-m x 6-m brick wall of thickness 30 cm and thermal conductivity 0.69 W/m °C are maintained at temperatures of 20°C and 5°C, respectively. Determine the rate of heat transfer through the wall, in W.arrow_forwardA 0.083-in-diameter electrical wire at 90°F is covered by 0.02-in-thick plastic insulation (k = 0.075 Btu/ h·ft·°F). The wire is exposed to a medium at 50°F, with a combined convection and radiation heat transfer coefficient of 2.5 Btu/h·ft2·°F. Determine if the plastic insulation on the wire will increase or decrease heat transfer from the wire.arrow_forward
- Consider steady heat transfer between two large parallel plates at constant temperature of T1 = 500K and T2 =300K that are L =2 cm apart. Assuming the surfaces to be black ( emissivity Ɛ = 1 ), determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plate filled with atmospheric air, (b) evacuated, (c) filled with fiberglass insulation, and (d) filled with superinsulation having an apparent thermal conductivity of 0.00015 W/m.˚C.arrow_forwardA person puts a few apples into the freezer at 15°C cool them quickly for guestswho are about to arrive. Initially, the apples are at a uniform temperature of 20°C,and the heat transfer coefficient on the surfaces is 8 W/m2·K. Treating the apples as9-cm-diameter spheres and taking their properties to be 840 kg/m3, Cp 3.81 kJ/kg·K, k = 0.418 W/m·K, and α =10-7 m2/s, determine the center and surface temperatures of the apples in 1 h. Also, determine the amount of heat transfer from each apple. Solve this problem using analytical one-term approximation method (notthe Heisler charts). Answer: Center: 11.2 ℃, Surface: 2.7 ℃, heat transfer: 17.2 kJarrow_forwardAn average man has a body surface area of 1.8 m2 and a skin temperature of 330C. The convective heat transfer coefficient for a clothed person walking in still air is expressed as h= 8.6V0.53 where V is the walking velocity in m/s. Assuming the average surface temperature of the clothed person to be 300C, determine the rate of heat lost by convection from an average man walking in still air at 100C at a walking velocity of 1.2 m/s.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
Understanding Conduction and the Heat Equation; Author: The Efficient Engineer;https://www.youtube.com/watch?v=6jQsLAqrZGQ;License: Standard youtube license