ICONE23-1207 KEVIN-HELMHOLTZ ISTABILITY OF LIQUID FILM ON WALL OF CYCLONE SEPARATOR

Abstract

In this work, theory analysis about K-H instability of film interface in swirling flow field in cyclone separator was performed. The momentum equations and continuity equations of each phase fluid were linearized by substitution of potential function firstly. Then the dynamic boundary condition and kinematic boundary condition were obtained based on stress analysis of film interface. According to the linearized equation and boundary conditions, the dispersion relation was established. Additionally, the motion law of film was obtained based on principle of stress equilibrium. Then the criterion for interface K-H instability was obtained. A computer program was developed according to theory model. Then simulation and analysis was performed on interface K-H instability under different conditions. It was found that centrifugal force of film could constrain interface K-H instability of film but the centrifugal force of steam could cause K-H instability. Additionally, film interface tended to unstable state with the increase in film thickness. It was also found that the increase in steam velocity could constrain interface instability when rise angle of swirl-vane of separator was less than a certain value. But the increase in steam velocity could cause instability when rise angle exceeded a certain value.