Since the correlation given in the textbook is so complicated, Dr. Roy wants to come up with a new correlation for convection over a sphere. He proposes the correlation to be NU D = 2+C Re Pr3 He used a steel sphere (conductivity of 42 W/m-K) of 20 cm diameter that generates steady 40 W heat. He placed it in air flow with 1 m/s where air temperature is 20°C. He then measured the steady state tempera- ture of the sphere surface to be 30°C. Based on his measurements, what is the convection coefficient? 31'8 /mK Using properties at film temperature, what should the value of C be as per Dr. Roy's calculations if he assumes m = 0.8? 0'142 What is the temperature at the center of the sphere? 30'38 C

Since the correlation given in the textbook is so complicated, Dr. Roy wants to come up with a new correlation for convection over a sphere. He proposes the correlation to be NU D = 2+C Re Pr3 He used a steel sphere (conductivity of 42 W/m-K) of 20 cm diameter that generates steady 40 W heat. He placed it in air flow with 1 m/s where air temperature is 20°C. He then measured the steady state tempera- ture of the sphere surface to be 30°C. Based on his measurements, what is the convection coefficient? 31'8 /mK Using properties at film temperature, what should the value of C be as per Dr. Roy's calculations if he assumes m = 0.8? 0'142 What is the temperature at the center of the sphere? 30'38 C

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 1.57P

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