Chapter 4 Transient Heat Conduction4-80A cylindrical ice block is placed on a table. The initial temperature of the ice block to avoid melting for 2 h is to be determined. Assumptions1Heat conduction in the ice block is two-dimensional, and thus the temperature varies in both x- and r- directions. 2 Heat transfer from the base of the ice block to the table is negligible. 3The thermal properties of the ice block are constant. 4The 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). Air T∞= 20°C xr(ro, L) Insulation Ice block TiPropertiesThe thermal properties of the ice are given to be k = 2.22 W/m.°C and α= 0.124×10-7m2/s. Analysis This cylindrical ice block can be treated as a short cylinder that can physically be formed by the intersection of a long cylinder of diameter D= 2
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