Fundamentals of Heat and Mass Transfer – Problem 1.1

Consider the geometry of Problem 2.14 for the case where the thermal conductivity varies with temperature as k = ko + aT. where ko = 10W/m-K, a =-10-3 W/m-K2, and T is in kelvins. The gradient at surface B is partial differential T/partial differential x = 30 K/m. What is partial differential T/partial differential y at…

Radioactive wastes are packed in a long, thin-walled cylindrical container. The wastes generate thermal energy nonuniformly according to the relation q = qo [1 – (r/ro)2], where q is the local rate of energy generation per unit volume, qo is a constant, and ro is the radius of the container. Steady-state conditions are maintained by…

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!…

A square isothermal chip is of width w = 5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated, while the front surface is exposed to the flow of a coolant at T infinity = I5 degree C. From reliability considerations, the chip temperature…

A blood warmer is to be used during the transfusion of blood to a patient. This device is to heat blood taken from the Blood Bank at 10°C to 37°C at a flow rate of 200 mL/min. The blood passes through tubing of length 2 m, with a rectangular cross-section of 6.4 mm x 1.6…

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…