The Rotating Machinery, High Mach Number Flow branch, found under the Fluid Flow > High Mach Number Flow branch (), contains three variations of the same predefined multiphysics interface (all with the name hmnf) for modeling gas flows where one or more of the boundaries rotate in a periodic fashion and the velocity magnitude is comparable to the speed of sound in the gas; that is, it flows in the transonic and supersonic range. The High Mach Number Flow, Laminar () and High Mach Number Flow, Turbulent () versions can be found under the High Mach Number Flow > Rotating Machinery, High Mach Number Flow branch (), when adding a physics interface. The physics interfaces can be used to model high-speed turbomachinery equipment.

The physics interfaces support Sutherland’s law for Thermal conductivity and Dynamic viscosity as the default option.