5. Conclusion

The mechanical equation for flow in the fixed parts of turbomachinery is based on the kinetic energy theorem of general mechanics, which states that the increase in energy of a particle is equal to the work of the forces acting on it. Bernoulli's equation for incompressible fluids and Barré de Saint-Venant's equation for compressible fluids are the mechanical equations of flow in fixed components, i.e. in a Galilean frame of reference or frame of inertia.

A reference system fixed on the wheel of a turbomachine is not a frame of reference of inertia. In other words, Newton's second relation, established under Galileo's assumptions, can no longer be applied. From the general theorems of mechanics on relative motion, we know that we can nevertheless apply the same equations as in absolute motion, provided we add two fictitious forces to the forces acting on the system....