3. Air enters a mixing device from ports 1 and 2 and exists from port 3 at the conditions shown in the figure below. The circular ports have diameters D1,

D2 and D3. Heating elements provide heat to the fluid at the rate Q = 67 kJ/s. In order to maintain the flow conditions at the outlet (port 3), impellers stir the flow inside the chamber. Air specific heat capacity at constant pressure is c, = 1.0 kJ/(kg · K). (a) Calculate the densities at ports 1, 2 and 3. The specific gas constant for air is r = 287 J · kg-1.K-!. (b) Find the flowrate Q3 at the outlet. (c) Find the power W power required to operate the device.

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