Chapter 4 Transient Heat Conduction4-54 The center temperature of potatoes is to be lowered to 6°C during cooling. The cooling time and if any part of the potatoes will suffer chilling injury during this cooling process are to be determined. Assumptions1 The potatoes are spherical in shape with a radius of r0= 3 cm. 2 Heat conduction in the potato is one-dimensional in the radial direction because of the symmetry about the midpoint. 3 The thermal properties of the potato are constant. 4 The heat transfer coefficient is constant and uniform over the entire surface. 5 The Fourier number is τ> 0.2 so that the one-term approximate solutions (or the transient temperature charts) are applicable (this assumption will be verified). PropertiesThe thermal conductivity and thermal diffusivity of potatoes are given to be k = 0.50 W/m⋅°C and α= 0.13×10-6m2/s. Analysis First we find the Biot number:BiW/m . C)m0.5 W / m C2==°°=hrk0190 03114((.).
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This note was uploaded on 01/19/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.