Generalization to a real compression stage made up of annular grids
Rotodynamic pumps -Design and performance analysis of axial flow pumps

The purpose of radial balance is to determine the position of a fluid path as it passes through the machine. When radial equilibrium is not respected, the trajectory moves towards or away from the machine axis, following a complex movement that makes it impossible to position it as a function of the distance travelled.

The laws already examined for constant axial velocity can no longer be used. For simplicity's sake, we try to respect: C_r = 0 for the entire flow.

The main flow directions are designated a (axial), u (tangential), r (radial) as shown in figure 4.

At any point M, the flow velocity C can be broken down into :