Pressure or Suction on Flat Plate with Dish/Dimple

[Joblack]

If there is a flat plate (say 15' long x 5' wide) with a dish/dimple 1' in diameter and 1/2" deep say 4' from the trailing edge with water flowing only on the one surface of the plate (ie the underside)at an angle of attack from 1 to 5 degrees. The plate is dished away from the water side, and the flow is along the long axis of the plate.
Would the dish/dimple cause a negative or positive pressure on the plate.

 

[ivymike]

Do you mean "would the pressure of the water on the plate be greater than or less than what it would be without the dimple?"

 

[Sparweb]

You could look in Hoerner's "Fluid Dynamic Drag" textbook for the "excressence drag" charts. There may be data for dimples, not just protruding fastener heads.

"incressence drag"???


Steven Fahey, CET