Airplane - Heat Problem

Please view attached heat problem. I am having trouble understanding the cylinder part/ and should be used to find the temperature. any help would be appreciated. thanks Assume that the body of an airplane is considered as a 20-m long hollow cylindrical structure made up of unknown composite material. The plane body has inside and outside diameters of 6 and 8 meters respectively. Assume that the thermal conductivity of the composite structure varies with radius according to the relation, K(r) = 2/r2. If the inside surface of the plane is exposed to convection coefficient of 20 W/m2 K and ambient temperature of 30 oC and the outside surface of the plane is exposed to a constant temperatur... click for more

Heat transfer using Reynolds Analogy

A circuit board with a dense distribution of integrated circuits (ICs) and the dimensions of 120mm by 120mm on a side is cooled by a parallel flow of atmospheric air with a velocity of 2 m/s. From wind tunnel tests under the same flow conditions , the average frictional shear stress on the upper surface is determined to be 0.0625N/m^2. What is the allowable power dissipation from the upper surface of the board if the average surface temperature of the ICs must not exceed the ambient air by more than 25 degrees C ? Answer given is---14.3 W ??? I have no idea what to do?

Forced Convection - Air at a pressure of 6000 N/m^2 and temperature of 300 degrees Celsius is flowing with a velocity

Please see the attached document regarding homework specifics. Thank-you for your help.

Forced Convection

Please see the attached file. Thank you.

There is a device which works as heat of pump.

There is a device which works as heat of pump. This device is able to heat the air at 1 degree per second. The velocity of hot air is 0.5 m/sec. The professor is placing an alluminium cup full of water. The problem is, how long its going to take the hot air from heating pump to rise the water from 25 deg to 34 deg. You are totally free to make any assumption.