Fluid mechanics - Finding force point of application

[ual8658]

I get how to find vertical and horizontal forces on a submerged surface (vertical = weight of fluid and horizontal = force on vertical projection). I also get how to find the point of application for the horizontal force using a moment balance. But how do you determine the point of application for the vertical force on the surface if that surface is something like a flat incline or a quarter circle?

 

[HimanshuM2376]

I get how to find vertical and horizontal forces on a submerged surface (vertical = weight of fluid and horizontal = force on vertical projection). I also get how to find the point of application for the horizontal force using a moment balance. But how do you determine the point of application for the vertical force on the surface if that surface is something like a flat incline or a quarter circle?

Since the vertical component of force = weight of the fluid contained by the curved surface . So it will act at the centre of gravity of the corresponding weight. For eg. For a quarter circle it will act at a distance of 4R/3π from straight edge.
Hope it is clear now.

 

[ual8658]

Since the vertical component of force = weight of the fluid contained by the curved surface . So it will act at the centre of gravity of the corresponding weight. For eg. For a quarter circle it will act at a distance of 4R/3π from straight edge.
Hope it is clear now.

Oh so just the centroid of an area basically? But only take the x-component of the centroid if its a vertical force.

 

[HimanshuM2376]

Oh so just the centroid of an area basically? But only take the x-component of the centroid if its a vertical force.

Precisely.