Cooling analysis of aluminum extrusion (forced convection, transient conduction): determine the minimum time required for an aluminum extrusion to cool to a maximum internal temperature of 40 °c. the extrusion has a square cross section of 4 cm x 4 cm and exits the extruder at a uniform temperature of 150 °c. 20 °c air can be directed towards the extrusion at a velocity of 15 m/s.

Acarnot refrigerator operates in a room in which the temperature is 21°c and of power when operating. if the food compartment of the refrigerator is consumes 3 kw to be maintained at 2°c, determine (a) the coefficient of performance of the cycle and (b) the rate of heat removal from the food compartment. refrigerator cycle that has a higher coefficient of performance than that of the discussed (e) is it possible to develop a carn ot refrigerator, operating between the same temperature limits? explain