ར να 3. A device of characteristic dimension h is submerged in a moving blood stream with width b. Consider blood as incompressible fluid with density p. Derive an expression for the drag force (Drag force is a frictional force which acts in the opposite direction of the motion) on the device in two situations: (A) when wake length is same entrance length, and (B) when wake length greater than entrance length. Assume steady state flow and neglect the effect of body force. (Wake is the region of disturbed flow downstream of a solid body, y caused by the flow of the fluid around the body) A B Ро Po Va h 3L Ро (2) vx(y) x=(1+²): (0 < y < 3L) 3H 3L Ро vx(y) H<L vx = (1+): (0 < y < 3L)

Fig: 1