Hydrostatic Force acting on Submerged Surface
Calculate the thrust force acting on a submerged surface.
The thrust force acting on a surface submerged in a liquid can be calculated as
F = pa A
=ρ g ha A (1)
where
F = thrust force (N)
pa = ρ g ha = average pressure on the surface (Pa)
A = area of submerged surface (m2)
ha = average depth (m)
ρ = density (kg/m3) (water 1000 kg/m3)
g = acceleration of gravity (9.81 m/s2)
Example - The thrust force acting on the side of a container
The trust force acting on the submerged vertical side of a container can be calculated as
F = pa A
= ((pt + pb) / 2) A
= (ρ g (ht + hb) / 2) A (2)
where
pt = pressure at the top of the submerged surface (Pa)
pb = pressure at the bottom of the submerged surface (Pa)
ht = depth at the top of the submerged surface (m)
hb = depth at the bottom of the submerged surface (m)
The thrust on a surface with width 1 m and height from 0 m to 2 m - in a water-filled container can be calculated as
F = (ρ g (ht + hb) / 2) A
= (1000 kg/m3) (9.81 m/s2) ((0 m) + (2 m)) / 2) ((1 m) (2 m))
= 19620 N
= 19.6 kN
Example - The thrust force acting on the bottom of a container
The trust force acting on the horizontal bottom of a submerged container can be calculated as
F = pb A
= ρ g hb A (2b)
The thrust on a bottom with width 1 m and length 2 m - on depth 1 m - in a water filled container can be calculated as
F = ρ g hb A
= (1000 kg/m3) (9.81 m/s2) (1 m) ((1 m) (2 m))
= 19620 N
= 19.6 kN