申論題

6.A gearbox operating at steady state receives 20 horsepower along its input shaft，delivers power along its output shaft，and is cooled on its outer surface according to Q = - h A (T_b - T₀ )，where =110°F is the temperature of the outer surface and T_。= 40°F is the temperature of the surroundings far from the gearbox. The product of the heat transfer coefficient h and outer surface area A is 35 Btu/h*R. For the gearbox, determine the power delivered along the output shaft，the rate of availability transfer accompanying heat， and the irreversibility rate, each in Btu/h. Express each quantity as a percentage of the input power.