During air cooling of oranges, grapefruit, and tangelos, the heat transfer coefficient for combined convection, radiation, and evaporation for air velocities of 0.11 < V< 0.33 m/s is determined experimentally and is expressed as h = 5.05 kair Re3/D, where the diameter Dis the characteristic length. Oranges are cooled by refrigerated air at 3°C and 1 atm at a velocity of 0.3 m/s. The thermal conductivity of the orange is given to be k= 0.70 W/m-°C. The thermal conductivity and the kinematic viscosity of air at the film temperature of (Ts+ Too)/2 = (15+3)/2 = 9°C are k= 0.02431 W/m-°C and v=1.417 x 10-5 m2/s, respectively. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air 3°C 1 atm Orange Determine the initial rate of heat transfer from a 0.04-m-diameter orange initially at 15°C with a thermal conductivity of 0.7 W/m·K. The initial rate of heat transfer is |W. 111111

During air cooling of oranges, grapefruit, and tangelos, the heat transfer coefficient for combined convection, radiation, and evaporation for air velocities of 0.11 < V< 0.33 m/s is determined experimentally and is expressed as h = 5.05 kair Re3/D, where the diameter Dis the characteristic length. Oranges are cooled by refrigerated air at 3°C and 1 atm at a velocity of 0.3 m/s. The thermal conductivity of the orange is given to be k= 0.70 W/m-°C. The thermal conductivity and the kinematic viscosity of air at the film temperature of (Ts+ Too)/2 = (15+3)/2 = 9°C are k= 0.02431 W/m-°C and v=1.417 x 10-5 m2/s, respectively. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air 3°C 1 atm Orange Determine the initial rate of heat transfer from a 0.04-m-diameter orange initially at 15°C with a thermal conductivity of 0.7 W/m·K. The initial rate of heat transfer is |W. 111111

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.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.20P

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During air cooling of oranges, grapefruit, andtangelos, the heat transfer coefficient for combined convection,radiation, and evaporation for air velocities of0.11 < V < 0.33 m/s is determined experimentally and isexpressed as h = 5.05 kair Re1/3/D, where the diameter Dis the characteristic length. Oranges are cooled by refrigeratedair at 5°C and 1 atm at a velocity of 0.3 m/s. Determine(a) the initial rate of heat transfer from a 7-cm-diameterorange initially at 15°C with a thermal conductivity of0.50 W/m·K, (b) the value of the initial temperature gradientinside the orange at the surface, and (c) the value of theNusselt number.
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