Hot coffee is contained in a cylindrical thermos bottle that is of length L-0.3m and is lying on its side (horizontally). The coffee container consists of a glass flask of diameter DI-7 cm sperated from an aluminum housing of diameter D2-0.08 m by air at atmospheric pressure. If the inner and outer temperatures are 75oC and 35 oC respectively, what is the heat loss from the coffee due to convection?

Note: The diagram attached below is the completion of the given question.

Also calculate the heat loss from the coffee due to radiation and the total heat loss

Explanation:

Glass diameter of the coffee container,

Glass radius of the coffee container, r₁ = 0.07/2 = 0.035 m

Diameter of the aluminium housing,

Radius of the aluminium housing, r₂ = 0.08/2 = 0.04 m

Inner temperature, T₁ = 75°C = 348 K

Outer temperature, T₂ = 35°C = 308 K

At , P = 1 atm

k = 0.0284 w/m-k,  v = 23.74 * 10⁻⁶,  , pr = 0.703,