CHAPTER 3
TOTAL HYDROSTATIC FORCE
ON SURFACES
CURVED SURFACES
Total hydrostatic force on Curved Surface
The easiest way to determine the resultant hydrostatic
force FR acting on a two-dimensional curved surface is
to determine the horizontal and vertical components FH
and FV separately.
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
Total hydrostatic force on Curved Surface
Horizontal Component, FH
𝑭𝑯 = 𝒑𝒄𝒈 𝑨
Vertical Component, FV
𝑭𝑽 = 𝜸𝑳 𝑽
Resultant Force, FR
𝑭=
(𝑭𝑯 )𝟐 +(𝑭𝑽 )𝟐
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
CASE I: Liquid is above Curved Surface
𝑳𝑺
𝑭𝑯 = 𝒑𝒄𝒈 𝑨
𝒉
𝑭𝑯
𝑭𝑯
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
CASE I: Liquid is above Curved Surface
𝑳𝑺
𝑭𝑽
𝑭𝑽
𝑭𝑽 = 𝜸𝑳 𝑽
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
CASE II: Liquid is below Curved Surface
𝑳𝑺
𝑭𝑯 = 𝒑𝒄𝒈 𝑨
𝒉
𝑭𝑯
𝑭𝑯
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
CASE II: Liquid is below Curved Surface
𝑳𝑺
𝑭𝑽
𝑭𝑽 = 𝜸𝑳 𝑽
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
Example
The given tank shown is 6m wide.
Neglecting atmospheric pressure, compute
the following:
a. Horizontal Force on the curve panel AB.
b. Vertical Force on the curve panel AB.
c. Resultant Force.
d. Angle that the resultant makes with the
horizontal.
e. Find the location of the FH and FV from C.
f. Find the location of the point where the
FR strikes the wall from A..
C
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3
Example
𝑭
𝐴
The gate shown is a quarter circle 8 ft
wide. Find the force F just sufficient to
prevent rotation about hinge B. Neglect
the weight of the gate.
𝐵
HYDROSTATIC FORCE ON CURVED SURFACE
CHAPTER 3