A 5-cm-diameter shaft rotates at 4500 rpm in a 15-cm long, 4500 rpm 8-cm-outer-diameter cast iron...

 

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A 5-cm-diameter shaft rotates at 4500 rpm in a 15-cm long, 4500 rpm 8-cm-outer-diameter cast iron bearing (k =70 W/m K) with a uniform clearance of 0.6 mm filled with lubricating oil (p=0.03 N. s/m² and k = 0.14 W/m K). The bearing is cooled externally by a liquid, and its outer surface is maintained at 40°C. Assuming there is no heat conduction through the shaft and its surfaces and assuming one-dimensional heat transfer, determine (a) the rate of heat transfer to the coolant, (b) the surface temperature of the shaft, and (c) the mechanical power wasted by the viscous dissipation in oil. 5 cm 15 cm 8 cm A 5-cm-diameter shaft rotates at 4500 rpm in a 15-cm long, 4500 rpm 8-cm-outer-diameter cast iron bearing (k =70 W/m K) with a uniform clearance of 0.6 mm filled with lubricating oil (p=0.03 N. s/m² and k = 0.14 W/m K). The bearing is cooled externally by a liquid, and its outer surface is maintained at 40°C. Assuming there is no heat conduction through the shaft and its surfaces and assuming one-dimensional heat transfer, determine (a) the rate of heat transfer to the coolant, (b) the surface temperature of the shaft, and (c) the mechanical power wasted by the viscous dissipation in oil. 5 cm 15 cm 8 cm

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Additional Assumptions Steady state in the prevails The heat generati... View the full answer