Simulation Example - Hydrostatic Equilibrium: Pressure on Two Submarines at Different Depths


Submarines are water craft designed to execute operations both on the surface and under water. The principal working mechanism of a submarine is determined primarily by the hydrostatic theory and Archimedes' Principle. Depending on the magnitude of the buoyancy force and the weight of the submarine, it is either positively, negatively or neutrally buoyant. When a submarine is submerged in water and stationary, the weight of the submarine should be equal to the buoyancy force. As the submarine sinks in water, the hydrostatic pressure experienced by the submarine increases. The external hydrostatic pressure is counterbalanced by the pressure within the submarine using pumps and sensors. The maximum depth of operation of a submarine is determined by the ability of the pumps and other pressure equipment to maintain internal pressure so as to counterbalance the external hydrostatic pressure. Hence, determining the hydrostatic pressure on a submarine is pivotal in its design and operation.

In this example, two toy submarines are placed in a pool at different depths.  We will visualize the pressure contours of the submarines using Ansys Fluent simulations.


The main objective of this example is to understand and visualize the pressure contours on the toy submarines at different depths in a pool using Ansys Fluent simulations. A secondary objective is to verify the CFD result of the hydrostatic pressure on the submarines using the analytical result.


Download the Mesh file required for setting up the simulation and associated Case and Data files here. Follow the instructions below to set up this simulation in Ansys Fluent starting with the Mesh file. In case you face any issues setting up or running the simulation, refer to the corresponding initial and final Case and Data files.

Alternate video link.

Results and Discussion

Let’s now analyze the simulation and understand the physics of the hydrostatic equilibrium on submarines.