For a flow in the xy plane, the x component of velocity is given by u = Ax2y2, where A = 0.4 m-3 · s-1, and x and y are measured in meters. (a) Find a possible y component for steady, incompressible flow. (b) Is it also valid for unsteady, incompressible flow? (c) How many possible y components are there? (d) Determine the equation of the streamline for the simplest y component of velocity (use C as constant).

On a average work day more than work place firs are reorted

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?

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented