Fundamentals of Heat and Mass Transfer Seventh Edition Problem – 1.21

An array of 10 silicon chips, each of length L=10 mm on a side, is insulated on one surface and cooled on the opposite surface by atmospheric air in parallel flow with T∞​=24°C and u∞​=40m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface….

Chips of width L = 15 mm on a side are mounted to a substrate that is installed in an enclosure whose walls and air are maintained at a temperature of Tsur =T=25C. The chips have an emissivity of ε = 0.60 and a max allowable temperature of Ts = 85 C. (a) If heat…

A transmission case measures W = 0.30 m on a side and receives a power input of Pi= 150 hp from the engine. If the transmission efficiency is η=0.93 and air flow over the case corresponds T =30 degree C and h=200 W/m2-K. What is the surface temperature of the transmission? All sample problems and notes…

A spherical interplanetary probe of 0.5-m diameter contains electronics that dissipate 150 W. If the probe surface has an emissivity of 0.8 and it does not receive radiation from other surfaces, such as the sun, what is the surface temperature of the probe? How useful was this post? Click on a star to rate it!…

The free convection heat transfer coefficient on a thin hot vertical plate suspended in still air can be determined from observations of the change in plate temperature with time as it cools. Assuming the plate is isothermal and radiation exchange with its surroundings is negligible, evaluate the convection coefficient at the instant of time when…