Ambient airCitrus fruits are very susceptible to cold weather, and extended exposure to-15°Csubfreezing temperatures can destroy them. Consider an 8 cm diameterorange that is initially at 15°C. A cold front moves in one night, and theambient temperature suddenly drops to -15°C, with a heat transfer coefficientof 15 W/m2.°C. Using the properties of water for the orange and assuming theambient conditions to remain constant for 4 h before the cold front movesout, determine if any part of the orange will freeze that night.OrangeT, = 15°C

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Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.21P: 1.21 In an experimental set up in a laboratory, a long cylinder with a 5-cm diameter, and an...

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1.21 In an experimental set up in a laboratory, a long cylinder with a 5-cm diameter, and an electrical resistance heater inside its entire length is cooled with water flowing crosswise over the cylinder at and a velocity of 0.8 m/s. For these flow conditions, 20 kW/m of power is required to maintain a uniform temperature of at the surface of the cylinder. When water is not available, air at is used with a velocity of 10 m/s to maintain the same surface temperature. However, in this case, the cylinder surface heat dissipation rate is reduced to 400 W/m. Calculate the convection heat transfer coefficients for both water and air, and comment on the reason for the differences in the values.
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