Beer in cylindrical cans of 150 mm height and 60 mm diameter has a temperature of 27 ◦C and shall be cooled in a refrigerator which has an air temperature of 4 ◦C. When does the beer cool more...

Beer in cylindrical cans of 150 mm height and 60 mm diameter has a temperature of 27 ◦C and shall be cooled in a refrigerator which has an air temperature of 4 ◦C. When does the beer cool more quickly: if the cans are laid down in the refrigerator, or if they are standing? Calculate approximately with the properties of air at the initial mean temperature (27 + 4) ◦C/2 = 15.5 ◦C. For this the thermal conductivity is λ = 0.0255W/Km, the kinematic viscosity is ν = 14.90 · 10−6 m
²/s, the Prandtl number is P r = 0.709, further, the thermal expansion coefficient is β∞ = 1/T∞ = 3.475 · 10−3 K^-1