A rectangular fin with k=43 W/m.C , thickness t=2 cm , length L=14 cm and width W=1 m. The base of the fin is maintained at a temperature of 200 C while the fin is exposed to a convection environment at T∞= 15 C and h∞ = 20 W/m2 .C .Using the chart , calculate the heat lost from the fin .

There is a 1.20-cm-thick stagnant air pocket. A) What thickness of cork would have the same R-factor as the stagnant air pocket? The thermal conductivity of air is 0.0230 W/m·K and of cork is 0.0460 W/m·K.in cm  B) What thickness of tin would be required for the same R-factor as a 1.20-cm-thick stagnant air pocket? The thermal conductivity of air is 0.0230 W/m·K and of tin is 66.8 W/m·K . in m i asked how to do this but got the wrong soloution

An insulated steam pipe is routed horizontally through an unheated room, then vertically to the ceiling. The pipe is insulated, and the outside diameter of the insulation is 15 cm. The horizontal and vertical lengths of pipe are both 4 m long. The outside-surface temperature of the insulation is 50°C, and the room temperature is 5°C. How much heat is lost from the insulation by convection?

Consider a power transistor encapsulated in an aluminum case that is attached at its base to a square aluminum plate of thermal conductivity k= 240W/m.K, thickness L= 6mm, and width W= 20mm. The case is joined to the plate by screws that maintain a contact pressure of 1 bar, and the back surface of the plate transfers heat by natural convection and radiation to ambient air and large surroundings at T∞ =Tsur -25°C. The surface has an emissivity of ε=0.9, and the convection coefficient is h=4 W/m².K. The case is completely enclosed such that heat transfer may be assumed to occur exclusively through the base plate. a) If the air-filled aluminum-to-aluminum interface is characterized by an area of A₁=2×10-4 m² and contact resistance of R+c= 1.375 K/W, what is the maximum allowable power dissipation if the surface temperature of the case, Ts,c, is not to exceed 85°C? S,C' Transistor case Ts. Pelec S,C' Enclosure W Isur Base plate, (k,ε) Interface, Ac Air Th 801 b) How much should the h be…