SI units of Pressure are Pascal Pa. SimScale shows m^2/s^2. Why?


Often we have come across the question that the SI unit for pressure is Pa. Why does SimScale show the unit to be m^2/s^2.

The following information will help:

  1. If the Analysis type is chosen to be ‘Incompressible flow’, then the units of pressure are shown as m^2/s^2 in the boundary conditions.

  1. For incompressible flow, we divide Pressure/density.Therefore, we can call this pressure to be kinematic pressure. Hence its units are different to the SI units of Pascal.

  2. For compressible flows, buoyant flows, we use pressure and the unit to be Pa i.e. SI units.

4.Same is true for the Pressure units in the initial condition for the different analysis type. incompressible prescribes the kinematic pressure in the initial conditions whereas the lateral follows SI units for the Pressure value.