1. Flow in the volute

In small centripetal turbines, the "volute" is responsible for around half of the energy loss, independently of thermal losses. We therefore need to be able to analyze the power dissipated by the fluid in this poorly understood part of the turbine. A kinematic study of the gas in the volute is essential if we are to know, to a good approximation, the components of the velocity.

For example, Euler's theorem (paragraph 4.2 ) shows us that we need to know the speed vector at the impeller inlet to determine the power supplied by the turbine.

The analytical determination of the components of the velocity vector in the volute is not straightforward, and the corresponding calculations will not be developed here [6] . Nevertheless, we will briefly outline the methodology...