Hydrostatic Pressure

Define pressure exerted by a fluid at equilibrium.

Hydrostatic pressure is defined as a pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic pressure increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.

  1. On the Project Tree, open the Analysis Workbench.
  2. Click on the desired analysis branch.
  3. Next to loads, click (Add).
  4. Choose (Hydrostatic Pressure) from the list.
  5. In the modeling window, select faces to apply hydrostatic pressure to.
  6. Optional: You can select the Add tangent faces check box.
  7. Locate the fluid surface by defining the X, Y, and Z coordinates under Coordinates of a point at liquid surface.
    Tip: You can also locate the coordinates in the modeling window using the graphical representation of the hydrostatic pressure load. Drag the ball around the model until it is in the desired position.
  8. Define the Depth direction X, Y, and Z directions.
  9. Specify units and value for Liquid density.
  10. Specify units and value for Pressure at liquid surface.
  11. Click OK.
    Note: If a gravity direction is already defined, the depth direction uses this existing definition. In this case, you can locate the surfaces elevation, but not change its direction.
The hydrostatic pressure load appears in the Project Tree. If selected, a graphic representation appears on the model.

Densities of Common Substances

Common material densities. Use as reference examples only.

Table 1. Material Densities
Material Temperature (Celcius) Density (kg/m3)
Acetone 25 785
Alcohol, propyl 25 800
Cement, Portland -- 1506
Concrete, gravel -- 2400
Fuel oil 15 890
Earth, packed -- 1520
Heating oil 20 920
Gasoline, natural 15 711
Gasoline, vehicle 15 737
Kerosene 15 820
Liquid Oxygen -183 1140
Propane -40 494
Sand, dry -- 1600
Sea water 25 1025
Water 4 1000