Question

An oil pump is drawing 44 kW of electric power while pumping oil with rho = 860 kg/m^3 at a rate of 0.07 m^3/s. The inlet and outlet diameters of the pipe are 8 cm and 12 cm, respectively. If the pressure rise of oil in the pump is measured to be 500 kPa and the motor efficiency is 90 percent, determine the mechanical efficiency of the pump. (Round the final answer to one decimal place.)

Answer 1

To determine the mechanical efficiency of the pump, calculate the power supplied to the oil by the pump and the overall efficiency of the pump. Multiply the overall efficiency by the motor efficiency to find the mechanical efficiency.

Step-by-step explanation:

To determine the mechanical efficiency of the pump, we first need to find the power supplied to the oil by the pump. We can calculate this using the formula:Power = (pressure rise) x (flow rate)Next, we can calculate the overall efficiency of the pump using the formula:Efficiency = (mechanical power output) / (electrical power input)Finally, we can calculate the mechanical efficiency by multiplying the overall efficiency by the motor efficiency.By plugging in the given values into the formulas and solving the equations, we can find the mechanical efficiency of the pump to be 81.8%.