For a curved surface submerged in a static liquid, the component of force exerted by the static fluid will be equal to:
Answers
If the surface is planar, a single resultant point force is found, mechanically equivalent to the distributed pressure load over the whole surface.
This resultant point force acts compressively, normal to the surface, through a point termed the “center of pressure”.Its magnitude is: F=γzkA, where:
γ is the fluid's specific gravity. For water, it is 9810 N/m3.
zk is the depth in which the center of gravity of the surface, the centroid, is situated.
A is the surface’s area.
The product (γ.zk), is the hydrostatic pressure at the depth of the centroid of the surface. In case the free surface of the liquid that contains the surface is under atmospheric pressure alone, the above equation is enough to describe the force. But in case the free surface is under additional pressure, this pressure will have an additional effect on the acting force. The value of the pressure in the center of gravity of the surface, is no longer (γ.zk). It is now γ(zk+p/γ), where p is the above-mentioned pressure.Calculating the magnitude of the force is done as described above. The determination of the point where this force applies, the “center of pressure,” is a little more complicated: