Experiments have been conducted to determine local heat transfer coefficients for flow perpendicular to a long, isothermal bar of rectangular cross section. The bar is of width c parallel to the flow, and height d normal to the flow. For Reynolds numbers in the range 104 Red ≤ 5×104, the face-averaged Nusselt numbers are well correlated by an expression of the form Nud = hd/k = C Rem Pr. 1/3 The values of C and m for the front face, side faces, and back face of the rectangular rod are found to be the following: Face cld C m Front 0.33 cld 1.33 0.674 1/2 Side 0.33 0.153 2/3 Side 1.33 0.107 2/3 Back 0.33 0.174 2/3 Back 1.33 0.153 2/3 Determine the value of the average heat transfer coefficient for the entire exposed surface (that is, averaged over all four faces) of ac = 40-mm-wide, d = 30-mm-tall rectangular rod. The rod is exposed to air in cross flow at V = 16 m/s, T = 300 K.

Experiments have been conducted to determine local heat transfer coefficients for flow perpendicular to a long, isothermal bar of rectangular cross section. The bar is of width c parallel to the flow, and height d normal to the flow. For Reynolds numbers in the range 104 Red ≤ 5×104, the face-averaged Nusselt numbers are well correlated by an expression of the form Nud = hd/k = C Rem Pr. 1/3 The values of C and m for the front face, side faces, and back face of the rectangular rod are found to be the following: Face cld C m Front 0.33 cld 1.33 0.674 1/2 Side 0.33 0.153 2/3 Side 1.33 0.107 2/3 Back 0.33 0.174 2/3 Back 1.33 0.153 2/3 Determine the value of the average heat transfer coefficient for the entire exposed surface (that is, averaged over all four faces) of ac = 40-mm-wide, d = 30-mm-tall rectangular rod. The rod is exposed to air in cross flow at V = 16 m/s, T = 300 K.

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.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.54P

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