Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
8th Edition
ISBN: 9781305387102
Author: Kreith, Frank; Manglik, Raj M.
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
error_outline
This textbook solution is under construction.
Students have asked these similar questions
how is a three-dimensional heat equation reduced if heat transfer occurs in an insulated long, thin rod or wire of a specific length? Explain what will be the new equation?
The boiling temperature of nitrogen at atmospheric pressure at sea level (1 atm pressure) is -196 °C. Therefore, nitrogen is commonly used in low-temperature scientific studies since the temperature of liquid nitrogen in a tank open to the atmosphere will remain constant at -196 °C until it is depleted. Any heat transfer to the tank will result in the evaporation of some liquid nitrogen, which has a heat of vaporization of 198 kJ/kg and a density of 810 kg/m3 at 1 atm.
Consider a 3-m-diameter spherical tank that is initially filled with liquid nitrogen at 1 atm and -196 °C. The tank is exposed to ambient air at 15° C, with a combined convection and radiation heat transfer coefficient of 35 W/m2⋅K. The temperature of the thin-shelled spherical tank is observed to be almost the same as the temperature of the nitrogen inside. Determine the rate of evaporation (in kg/s) of the liquid nitrogen in the tank as a result of the heat transfer from the ambient air if the tank is insulated with…
The boiling temperature of nitrogen at atmospheric pressure at sea level (1 atm) is -196°C. Therefore, nitrogen is commonly used in low temperature scientific studies since the temperature of liquid nitrogen in a tank open to the atmosphere will remain constant at -196°C until the liquid nitrogen in the tank is depleted. Any heat transfer to the tank will result in the evaporation of some liquid nitrogen, which has a heat of vaporization of 198 kJ/kg and a density of 810 kg/m3 at 1 atm. Consider a 3-m-diameter spherical tank initially filled with liquid nitrogen at 1 atm and 196°C. The tank is exposed to 22°C ambient air with a heat transfer coefficient of 22 W/m2 · °C. The temperature of the thin-shelled spherical tank is observed to be almost the same as the temperature of the nitrogen inside. Disregarding any radiation heat exchange, determine the rate of evaporation of the liquid nitrogen in the tank as a result of the heat transfer from the ambient air in kg/sec. Answer in…
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
- The heat transfer coefficient for a gas flowing over a thin float plate 3-m long and 0.3-m wide varies with distance from the leading edge according to hc(x)=10x1/4Wm2K If the plate temperature is 170C and the gas temperature is 30C, calculate (a) the average heat transfer coefficient, (b) the rate of heat transfer between the plate and the gas, and (c) the local heat flux 2 m from the leading edge. Problem 1.18arrow_forwardA spherical communications satellite, 2 m in diameter, is placed in orbit around the earth. The satellite generates 1000 W of internal power from a small nuclear generator. If the surface of the satellite has an emittance of 0.3, and is shaded from solar radiation by the earth, estimate its surface temperature.arrow_forwardA horizontal, 3-mm-thick flat-copper plate, 1-m long and 0.5-m wide, is exposed in air at 27C to radiation from the sun. If the total rate of solar radiation absorbed is 300 W and the combined radiation and convection heat transfer coefficients on the upper and lower surfaces are 20 and 15W/m2K, respectively, determine the equilibrium temperature of the plate.arrow_forward
- Explain in your own words: (a) In what way is the heat transfer through a large steel plate that has its surfaces at specific temperatures? (B) What are the patterns in which the temperature at one surface of the steel plate is not specified, but the surface is exposed to a fluid at a specified temperature?arrow_forwardUsing your own words and relevant equations, explain why the rate of heat transfer through convection is faster than the rate of heat transfer through conduction.arrow_forwardIllustrate the concept of convection in heat transfer operation and also differentiate forced convection and natural convection with suitable examples. Why thermal conductivity of liquid decreases whereas that of gas increases by increasing temperature?arrow_forward
- 3- You have experienced convection cooling if you have ever extended your handout of the window of a moving vehicle or into a flowing water stream. With the surface of your hand at a temperature of 30 oC, determine the convection heat flux for a) a vehicle speed of 35 km/h in air at -5 oC with convection coefficient of 40 W/m2 .K and b) a velocity of 0.2 m/s in a water stream at 10 oC with convection coefficient of 900 W/m2.K. Which condition would feel colder? Contrast theseresults with a heat loss of approximately 30 W/m2 under normal room conditions.arrow_forwardConsider a 1 m high rectangular closed space with two surfaces separated by an air gap of 0.125 m (at 1 atm pressure). Surface temperatures in the air gap are 34 0C and -9 0C. Find the natural convection heat transfer rates for the horizontal orientation (hot surface down), vertical orientation, and the hot surface inclined at an angle of 80° for this closed gap.arrow_forwardSolve for the rate of natural convection heat loss from a flat 1-m square, restaurant grill heated to 227⁰Cin ambient air at 27⁰C ifa) the grilling surface is horizontal facing upc) the grilling surface is horizontal facing downarrow_forward
- Answer all questions strictly otherwise dont attempt it. conduction convection experimentIf the material of the fins can be changed to reduce the total thermal resistance, which material is advantageous to use?If you could change the speed or temperature of the air to reduce the total thermal resistance, how would you change it?List all the causes that can cause errors in your conclusions, and consider how changes in those causes affect the results.arrow_forwardWhat is thermal conductivity? How the thermal conductivity of Solid, liquid and gases are varying with temperatures and pressure? Explain the variation of thermal conductivity of metals and non-metals with temperatures?arrow_forwardSilver shafts of 0.1 m diameter are heat treated in a gas-fired furnace whose gases are at 1200 K and provide a convection coefficient of 50 W/m².K. The shafts enter the furnace at 400 K and they remain in the furnace for 1000 s. Determine the centerline temperature of the shaft when it comes out of the furnace?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