The velocity components for a flow of an incompressible fluid are given by the following equations:
u=kx (y + z);
v=ky (x + z);
w=-k z(x + y)- 22.
• Determine the value of “k” in order to have a physically possible flow.
• Determine if the flow is steady or not (use the value of “K”, obtained in the first part).
• Determine if the flow is uniform or not (use the value of “K”, obtained in the first part).
• Determine if the flow is rotational or not (use the value of “k”, obtained in the first part). If it
is a rotational flow, compute the magnitude of rotations at a point A which has the following
coordinates: x=1, y=1, z=1.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?