The Interaction of a Gas with Solid and Liquid Particles in a Rotating System

Heshmat, H. and Pinkus, O. “The Interaction of a Gas with Solid and Liquid Particles in a Rotating System,” Proc. 6th Symposium on Transfer and Utilization of Particulate Control Technology, 1, EPRI/EPA, EPRI CS-4918 (1986): 16.1-15.

A set of Navier-Stokes equations is given in a three-dimensional cylindrical coordinate system that, in addition to the inertia and viscous terms, includes centrifugal and Coriolis forces.  These equations are then applied to two-phase flow systems, one a gas-solid stream, the other gas (or vapor) – liquid.  For both systems the analysis takes gas velocity as an input and predicts particle trajectory as a function of its initial characteristics. 

For solids, the analysis also determines the ricochet path of the particle as determined by its coefficient of friction and geometry.  the analysis can be applied to particulates in the turbine, compressor, or fan blading in order to determine their impact on the walls, or to particulate elimination by means of centrifugal separation.  For the gas-liquid system, the analysis determines the relative velocities and trajectories of the droplets in the field of a rotating gas or vapor and their rate of vaporization as a function of the prevailing flow field and inlet conditions.  The computer0obtained results provide the conditions required to avoid collision with the walls.  These results can be applied to turbine blades in which the steam contains either moisture or solid particles with a view of minimizing blade erosion.