Heat and Mass Transfer: Fundamentals and Applications
5th Edition
ISBN: 9780073398181
Author: Yunus A. Cengel Dr., Afshin J. Ghajar
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 1, Problem 97P
An electronic package with a surface area of 1 m2 placed in an orbiting space station is exposed to space. The electronics is this package dissipate all 1 kW of its power to the space through its exposed surface. The exposed surface has an emissivity of 1.0 and an absorptivity of 0.25. Determine the steady-state exposed surface temperature of the electronic package (a) if the surface is exposed to a solar flux of 750 W/m2 , and (b) if the surface is not exposed to the sun.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
A particular furnace is shaped like a section of a cone. The top surface of the furnace is
uniformly heated by a resistance heater. During operation, the top surface is measured to
be 800 K and the power supplied to the resistance heater is 1750 W/m². The sidewall of
the furnace is perfectly insulated with & = 0.2. If the emissivity of the top and bottom
surfaces are ε = 0.5 and ε = 0.7, respectively, determine the temperatures of the sidewall
and the bottom surface of the furnace.
A₁
A2
A3
→→D₂ = 20 mm
D₁ = 40 mm
L = 50 mm
Two plates are separated by two radiation shields with emissivities of 0.10 and 0.15for both sides. The two plates are said to have maintained uniform temperatures600 K (emissivity = 0.6) and 300 K (emissivity = 0.7). Calculate the net rate of heattransfer (W/m2) between the two plates with and without the shields per unitsurface area. Determine the rate of heat transfer (W/m2) between the two plateswhen one plate (emissivity = 0.10) is removed. Assume that the temperatures ofradiations shield are in steady operation.
A flat-plate collector with one glass cover is placed in horizontal. The absorber plate temperature is 95 oC and its emittance is 0,12. The glass cover temperature is 45 oC, and the (glass) cover has an emittance of 0.85. The plate-cover spacing is 15 mm. The ambient and surrounding temperature are equal at 25 oC. The wind velocity is 20 km/hour. If solar radiation is 850 W/m2 , and the plate absorptivity is 95%, calculate over all heat transfer coefficient losses and the useful energy (W/m2 ). ----- s
Chapter 1 Solutions
Heat and Mass Transfer: Fundamentals and Applications
Ch. 1 - How does the science of heat transfer differ from...Ch. 1 - What is the driving force for (a) heat transfer,...Ch. 1 - Prob. 3CPCh. 1 - How do rating problems in heat transfer differ...Ch. 1 - What is the difference between the analytical and...Ch. 1 - Prob. 6CPCh. 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 - An ideal gas is heated from 50C to 80C (a) at...Ch. 1 - Prob. 12CPCh. 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 - Prob. 18PCh. 1 - Prob. 19PCh. 1 - A 60-gallon water heated is initially filled with...Ch. 1 - Prob. 21PCh. 1 - Prob. 22PCh. 1 - Prob. 23PCh. 1 - Prob. 24PCh. 1 - Prob. 25PCh. 1 - Prob. 26PCh. 1 - Prob. 27PCh. 1 - Prob. 28PCh. 1 - A 5-m6-m8-m room is to be heated by an electrical...Ch. 1 - Prob. 30PCh. 1 - Prob. 31PCh. 1 - Air enters the duct of an air-conditioning system...Ch. 1 - Define thermal conductivity, and explain its...Ch. 1 - Prob. 34CPCh. 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 - Prob. 39CPCh. 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. 53PCh. 1 - The inner and outer surfaces of a 0.5-cm thick...Ch. 1 - Prob. 55PCh. 1 - Prob. 56PCh. 1 - The north wall of an electrically heated home is...Ch. 1 - Prob. 58PCh. 1 - Prob. 59PCh. 1 - Prob. 60PCh. 1 - A concreate wall a surface area of 20 m2 and a...Ch. 1 - Prob. 62PCh. 1 - Prob. 63PCh. 1 - Prob. 64EPCh. 1 - Prob. 65EPCh. 1 - Air at 20C with a convection heat transfer...Ch. 1 - Prob. 67PCh. 1 - Prob. 68PCh. 1 - Prob. 69PCh. 1 - Prob. 70PCh. 1 - Prob. 71PCh. 1 - Prob. 72PCh. 1 - Prob. 73PCh. 1 - Prob. 74PCh. 1 - Prob. 75PCh. 1 - Prob. 76EPCh. 1 - Prob. 77EPCh. 1 - Prob. 78PCh. 1 - Prob. 79PCh. 1 - Prob. 80PCh. 1 - Prob. 81PCh. 1 - Prob. 82PCh. 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. 86PCh. 1 - Two surfaces, one highly polished and the other...Ch. 1 - A spherical interplanetary probe with a diameter...Ch. 1 - Prob. 89PCh. 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. 94PCh. 1 - Prob. 95PCh. 1 - Prob. 96PCh. 1 - An electronic package with a surface area of 1 m2...Ch. 1 - Consider steady heat transfer between two large...Ch. 1 - Prob. 99PCh. 1 - Prob. 100PCh. 1 - A 2-in-diameter spherical ball whose surface is...Ch. 1 - Prob. 102PCh. 1 - A 3-m-internal-diameter spherical tank made of...Ch. 1 - Prob. 104PCh. 1 - Solar radiation is incident on a 5-m2 solar...Ch. 1 - Prob. 106PCh. 1 - Prob. 107PCh. 1 - Prob. 108PCh. 1 - Prob. 109EPCh. 1 - An AISI 304 stainless steel sheet is going through...Ch. 1 - Prob. 111PCh. 1 - Prob. 112CPCh. 1 - Prob. 113PCh. 1 - Prob. 114PCh. 1 - Prob. 115PCh. 1 - Prob. 116PCh. 1 - Prob. 117PCh. 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. 121CPCh. 1 - Why is it necessary to ventilate buildings? What...Ch. 1 - Consider a house in Atlanta, Georgia, that is...Ch. 1 - Prob. 124PCh. 1 - Prob. 125PCh. 1 - Prob. 126PCh. 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. 129PCh. 1 - Prob. 130PCh. 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. 135PCh. 1 - Prob. 136PCh. 1 - Prob. 137PCh. 1 - Consider a person standing in a room maintained at...Ch. 1 - Prob. 139PCh. 1 - Prob. 140PCh. 1 - Prob. 141PCh. 1 - Prob. 142PCh. 1 - Prob. 143PCh. 1 - Prob. 144PCh. 1 - Prob. 145PCh. 1 - Prob. 146PCh. 1 - A 2-kW electric resistance heater submerged in...Ch. 1 - Prob. 148PCh. 1 - A cold bottled drink (m=2.5kg,cp=4200J/kg.K) at...Ch. 1 - Prob. 150PCh. 1 - Air enters a 12-m-long, 7-cm-diameter pipe at 50oC...Ch. 1 - Prob. 152PCh. 1 - Steady heat conduction occurs through a...Ch. 1 - Heat is lost through a brick wall (k=0.72W/m.K),...Ch. 1 - Prob. 155PCh. 1 - A 40-cm-long, 0.4-cm-diameter electric resistance...Ch. 1 - Prob. 157PCh. 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. 160PCh. 1 - Prob. 161PCh. 1 - A persons head can be approximated as a...Ch. 1 - A person standing in a room loses heat to the air...Ch. 1 - Prob. 164PCh. 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
- Determine the rate of radiant heat emission in watts per square meter from a blackbody at (a) 15C, (b) 600C, and (c) 5700C.arrow_forwardA certain body at 20C is displayed on a top of a building during the night. The body sees nothing but the sky which has an effective temperature of 110K. Determine the heat transfer rate from the body to the sky if the body temperature is maintained at 23C, the surface emissivity of the body is equal to 0.92, and none of the radiation going out of the comes backarrow_forwardTwo parallel plates (1mx0.5m) are maintained at uniform temperatures of T₁ = 1000K and T₂ = 500K and have emissivities of &, = 0.2 and ₂ = 0.5 respectively. Determine the net rate of radiation heat transfer between the two surfaces of the plates. F12=0.285 and o=5.669×10 W/m²K.arrow_forward
- a certain body at 20 C is display on a top of a building during the night. the body sees nothing but the sky which has effective temperature of 110 k. determine the heat transfer rate from the body to the sky if the body temperature is maintained at 23 C. the surface to the sky emissivity of the body is equal to 0.92arrow_forwardConsider a person whose exposed surface area is 1.7 m2, emissivity is 0.7, and surface temperature is 32°C. Determine the rate of heat loss from that person by radiation in a large room having walls at a temperature of (a) 300 K and (b) 280 K.arrow_forwardSolar radiation is incident on the front surface of athin plate with direct and diffuse components of 300 and 250W/m2, respectively. The direct radiation makes a 30° anglewith the normal of the surface. The plate surfaces have a solarabsorptivity of 0.63 and an emissivity of 0.93. The air temperatureis 5°C and the convection heat transfer coefficient is20 W/m2·K. The effective sky temperature for the front surfaceis -33°C while the surrounding surfaces are at 5°C forthe back surface. Determine the equilibrium temperature ofthe plate.arrow_forward
- Consider a cubical furnace with a side length of 3 m. The top surface is maintained at 700 K. The base surface has an emissivity of 0.90 and is maintained at 950 K. The side surface is black and is maintained at 450 K. Heat is supplied from the base surface at a rate of 340 kW. Determine the emissivity of the top surface and the net rates of heat transfer between the top and the bottom surfaces, and between the bottom and side surfaces.arrow_forwardConsider a large plane wall of thickness L = 0.8 ft and thermal conductivity k = 1.2 Btu/h-ft-°F. The wall is covered with a material that has an emissivity of ε = 0.80 and a solar absorptivity of a = 0.60. The Inner surface of the wall is maintained at T₁ = 524 R at all times, while the outer surface is exposed to solar radiation that is incident at a rate of q solar = 300 Btu/h-ft2. The outer surface is also losing heat by radiation to deep space at O K. 0 Plate a solar o = 0.1714 x 10-8 Btu/h ft2 R4 Sun If the temperature of the outer surface of the wall is 556.39 R, determine the rate of heat transfer through the wall when steady operating conditions are reached. (Round your answer up to 2 decimal places.) 51 Btu/h-ft2 (per The rate of heat transfer through the wall when steady operating conditions are reached unit area)arrow_forwardA radiator in a domestic heating system operates at a surface temperature of 55°C. Assuming the radiator behaves as a black body, the rate at which it emits the radiant heat per unit area is (assume o = 5.67 x 10-8 W/m²K4)arrow_forward
- Two long parallel plates of same emissivity 0.5 are maintained at different temperatures and have radiation heat exchange between them. The radiation shield of emissivity 0.25 placed in the middle will reduce radiation heat exchange toarrow_forwardAccording to an Atomic Energy Commissionreport, a hydrogen bomb can be approximated as a large fireball at a temperature of 7200 K. You are to assess theimpact if such a bomb exploded 5 km above a city. Assumethe diameter of the fireball to be 1 km, and the blast to last15 s. Investigate the level of radiation energy people, plants,and houses will be exposed to and how adversely they will beaffected by the blast.arrow_forwardA 5-in-diameter spherical ball is known to emit radiation at a rate of 550 Btu/h when its surface temperature is 950 R. Determine the average emissivity of the ball at this temperature.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
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license