During air cooling of steel balls, the convection heat transfer coefficient is determined experimentally as a func- tion of air velocity to be h 17.9v054 for 0.5 < v< 2 m/s, where h and v are in w/m2.k and m/s, respectively. consider a 24-mm-diameter steel ball initially at 300°c with a thermal conductivity of 15 w/m-k. the steel balls are cooled in air at 10°c and a velocity of 1.5 m/s. determine the initial values of the heat flux and the temperature gradient in the steel ball at the surface.

To design a steam turbine to produce 12,000 hp power. a engineer comsiders using a steady state stean low st 1160fr and engineer considers using a steady state steam flow at 1160°r and 450 psia to drive this steam turbine. the exhaust of the steam is cooled by the lake (vacuum). heat losing to the surroundings is measured at a rate of 555.55 btu/s. (a) sketch the system with the given conditions. (b) neglecting kinetic and potential energy changes from inlet to exit, determine the volumetric flow rate of the steam at the inlet, (ft'/hr). must clearly show unit conversions at crtical terms.