Homework Answers
Add Answer to:
A stone wall whose emissivity of 0.95 reaches a maximum temperature of 50°C. The radiation heat...
Radiation heat transfer: Two perfectly black surfaces (each with emissivity ε = 1.0) are constructed such...
Radiation heat transfer: Two perfectly black surfaces (each with emissivity ε = 1.0) are constructed such that all the radiant energy leaving a surface at 800 °C (1073 K) reaches the other surface. The temperature of the other surface, with area A = 2 m2, is maintained at 250 °C (523 K). Using the formula Q = ε σ A (THot4 – TCold4) calculate the heat transfer (in kW) of the surface maintained at 800 °C. The Stefan-Boltzmann constant, σ...
A wall panel is insulated on the back and exposed to solar radiation on the front...
A wall panel is insulated on the back and exposed to solar radiation on the front surface. The exposed surface of the plate has an absorptivity α = 0.8 for radiation (i.e. 80% of radiant energy is absorbed). Solar radiation arrives to the panel at a rate of 1 kW⁄m2. The panel emissivity ϵ = 1 and the surrounding air temperature is 25°C. a. If we assume radiation is the only mechanism of heat transfer, in this scenario determine the...
P1 (50 pts.) - A large plane wall has a thickness L-60 cm and thermal conductivity...
P1 (50 pts.) - A large plane wall has a thickness L-60 cm and thermal conductivity k 25 W/m-K. On the left surface (x-0), it is subjected to a uniform heat flux qo while the surface temperature To is constant. On the right surface, it experiences convection and radiation heat transfer while the surface temperature is TL-225°C and the surrounding temperature is 25°C. The emissivity and the convection heat transfer coefficient on the right surface are 0.7 and 15 W/m2-K,...
A household oven door of 0.6-m height and 0.7-m width reaches an average surface temperature of...
A household oven door of 0.6-m height and 0.7-m width reaches an average surface temperature of 32°C during operation. The temperature of ambient air is 22°C. Assuming the door has an emissivity of 0.8 and the surroundings are also at 22°C, determine the heat transfer by free convection and the heat transfer by radiation. 1) What is the volumetric thermal expansion coefficient of air at the film temperature outside the oven door, in 1/K? 2) What is the Rayleigh number...
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate...
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate per unit length of the tube due to free convection. 2) Air at -10°C flows at 10 m/s over the roof plate of two 5m length rooms whose air is at Too-200C. The roof plate is 0.20-m thick concrete (k = 0.6 w/ m. K)....
The temperature distribution across a wall 0.2 m thick at a certain instant of time is...
The temperature distribution across a wall 0.2 m thick at a certain instant of time is T(x) = a + bx + cxº, where T is in degrees Celsius and x is in meters, a = 200°C, b = -190°c/m, and c = 30°C/m2. The wall has a thermal conductivity of 1 W/m.k. (a) On a unit surface area basis, determine the rate of heat transfer into and out of the wall and the rate of change of energy stored...
The heat question and would like to have work solution. The answers are (c) 136.6 (d)...
The heat question and would like to have work solution. The
answers are (c) 136.6 (d) < 2%. thank you.
An long cylindrical vaccuum chamber shown in Figure 1, is used to anneal single titanium rods by maintaining their temperature at 800 °C for an extended period of time. Heat is introduced into the rods internally by induction. The insulation surrounding the chamber has a thicknesss of 50 mm and thermal conductivity of 0.1 W/m.K. The convective heat transfer coefficient...
The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation...
The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation = ceAT4 t where a 5.67x108 J/(s m2. K4) is the Stefan-Boltzmann constant, A is the surface area of the object, and T is its absolute temperature in kelvin. The symbol e stands for the emissivity of the object, which is a measure of how well it radiates. An ideal jet-black (or black body) radiator has e 1, whereas a perfect reflector has e...
An animal's body has a skin temperature of 33 °C and is the room temperature where...
An animal's body has a skin temperature of 33 °C and is the room temperature where the walls are at temperature 29 °C. If the emissivity is 1 and the body area is 1.5 m2. What is the rate of heat transfer by radiation? ( Stefan-Boltzmann constant = 5.67 x 10 -8 J/s m?k4) 42 W 38 W 72 W O 54 W O 63 W
Cherry-red embers in a fireplace are at 835°C and have an exposed area of 0.240 m2...
Cherry-red embers in a fireplace are at 835°C and have an exposed area of 0.240 m2 and an emissivity of 0.980. The surrounding room has a temperature of 15.0°C. If 50% of the radiant energy enters the room, what is the net rate of radiant heat transfer in kilowatts? Radiation makes it impossible to stand close to a hot lava flow. Calculate the rate of heat transfer by radiation in kilowatts from 1.00 m2 of 1140°C fresh lava into 35.0°C...
P1 (50 pts.) - A large plane wall has a thickness L-60 cm and thermal conductivity k 25 W/m-K. On the left surface (x-0), it is subjected to a uniform heat flux qo while the surface temperature To is constant. On the right surface, it experiences convection and radiation heat transfer while the surface temperature is TL-225°C and the surrounding temperature is 25°C. The emissivity and the convection heat transfer coefficient on the right surface are 0.7 and 15 W/m2-K,...
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate per unit length of the tube due to free convection. 2) Air at -10°C flows at 10 m/s over the roof plate of two 5m length rooms whose air is at Too-200C. The roof plate is 0.20-m thick concrete (k = 0.6 w/ m. K)....
The temperature distribution across a wall 0.2 m thick at a certain instant of time is T(x) = a + bx + cxº, where T is in degrees Celsius and x is in meters, a = 200°C, b = -190°c/m, and c = 30°C/m2. The wall has a thermal conductivity of 1 W/m.k. (a) On a unit surface area basis, determine the rate of heat transfer into and out of the wall and the rate of change of energy stored...
The heat question and would like to have work solution. The
answers are (c) 136.6 (d) < 2%. thank you.
An long cylindrical vaccuum chamber shown in Figure 1, is used to anneal single titanium rods by maintaining their temperature at 800 °C for an extended period of time. Heat is introduced into the rods internally by induction. The insulation surrounding the chamber has a thicknesss of 50 mm and thermal conductivity of 0.1 W/m.K. The convective heat transfer coefficient...
The rate of heat transfer by emitted radiation is determined by the Stefan-Boltzmann law of radiation = ceAT4 t where a 5.67x108 J/(s m2. K4) is the Stefan-Boltzmann constant, A is the surface area of the object, and T is its absolute temperature in kelvin. The symbol e stands for the emissivity of the object, which is a measure of how well it radiates. An ideal jet-black (or black body) radiator has e 1, whereas a perfect reflector has e...
An animal's body has a skin temperature of 33 °C and is the room temperature where the walls are at temperature 29 °C. If the emissivity is 1 and the body area is 1.5 m2. What is the rate of heat transfer by radiation? ( Stefan-Boltzmann constant = 5.67 x 10 -8 J/s m?k4) 42 W 38 W 72 W O 54 W O 63 W
Most questions answered within 3 hours.
-
A solid, uniform disk of radius 0.250 m and mass 53.7 kg rolls
down a ramp...
asked 1 hour ago -
Given the following table of high speed internet access vs.
annual home income:
Home Income
%...
asked 2 hours ago -
A baseball batter hits a 0.145kg baseball straight up into the
air. The baseball leaves the...
asked 2 hours ago -
An FM modulator is tested using
single-tone baseband signal with frequency of 50kHz and a sprectrum...
asked 3 hours ago -
Write the ionic equations for the first stage of salts
hydrolysis.
Anion, Cation?
Na2S
NiSO4
K2SO4...
asked 4 hours ago -
suppose there is a normally distributed population with a mean of
250 and a standard deviation...
asked 5 hours ago -
Question Three
Suppose you as project manager are using the Waterfall
development methodology on a large...
asked 6 hours ago -
Which statement is not true about welfare in Canada?
A.Benefits typically vary based on one's ability...
asked 6 hours ago -
Please help me with FLOWCHART and UML diagram for class,
thank you!
#include <iostream>
#include <fstream>...
asked 7 hours ago -
3. Describe the “logic circuit” of the Lac operon. Which
proteins are bound or not to...
asked 7 hours ago -
Ayesha’s adjusted gross income is $60,000 in 2019. She donated a
piece of artwork with a...
asked 7 hours ago -
For Dijkstra’s shortest path algorithm:
a. Give the Big-O time for Dijkstra’s shortest path algorithm
and...
asked 7 hours ago