Chapter 4 Transient Heat Conduction 4-104 The center temperature of meat slabs is to be lowered by chilled air to below 5 ° C while the surface temperature remains above -1 ° C to avoid freezing. The average heat transfer coefficient during this cooling process is to be determined. Assumptions 1 The meat slabs can be approximated as very large plane walls of half-thickness L = 5-cm. 2 Heat conduction in the meat slabs is one-dimensional because of symmetry about the centerplane. 3 The thermal properties of the meat slab 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). Properties The thermal properties of the beef slabs are given to be ρ = 1090 kg/m 3 , C 3.54 kJ/kg.°C, k = 0.47 W/m.°C, and α = 0.13 × 10 p =-6 m 2 /s. Analysis
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