Axis Ca hand n frostal Cohaed n fruntal fretal Shupe Shupe Hall oylinder Shape Squar cylinder Plae: 21 12 20 Thie pla -D 16 1.7 wal 14 Halfube Eiguilateral tiangle 1.2 Heugon: 23 20 -1.0 0.7 Co hamd on frental ara Shape Roandel rem eien LH: 10 20 1.16 090 0.70 D64 30 23 0.9 Elipial cylinder Laminar Turbulent 1:1 12 03 02 015 025

7.27 A thin smooth disk of diametd, D is immersed parallel to a uniform stream of velocity U. Assuming laminar flow and using flat-plate theory as a guide, develop an approximate formula for the drag of the disk.

the flow of a stream U, past a blunt flat plate creates a broad low-velocity wake . , with only half of the flow shown due to symmetry. The velocity profile behind the plate is idealized as “dead air" (near-zero velocity) behind the plate, plus a higher velocity, decaying vertically above the wake according to the variation u = U, + AU e2, where L is the plate height and z = 0 is the top of the wake. Find AU as a function of stream speed Ug. behind the plate. A simple model is given in Fig. Uo Exponential curve Width b Uo into paper U+AU Dead air (negligible velocity) € -

An incompressible fluid flows past an impermeable flat plate, as in Fig. . , with a uniform inlet profile u = U, and a cubic polynomial exit profile (3η - η' where n= 2 Compute the volume flow Q across the top surface of the control volume. Ug у 3б Q? Uo y=0 CV Cubic Solid plate, width b into paper

A ship 50 m long, with a wetted area of 800 m2, has the hullshape tested in Fig. There are no bow or stern bulbs.The total propulsive power available is 1 MW. For seawaterat 20°C, plot the ship’s velocity V kn versus power Pfor 0 < P <1 MW. What is the most efficient setting?