To cool a summer house without using a vapor compression refrigeration cycle, hot air is directed through a pipe and is submerged in the closest lake. The pipe is made of plastic with k = 0.15 W/mK with volumetric flow rate of 0.02 m3/s and inlet air temperature of 32˚C. If the water temperature is kept at 15˚C with a convection coefficient of 1000 W/m2K at the outer surface of the pipe, calculate the length that is needed to provide a discharge temperature of 22˚C (in meters)?

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature