Study on Dynamic Coefficients of Concentric Rotor in Finite-Length Large Gap Annular Flow

Based on the theoretical model developed by us, the zero and first order perturbation equations of 3D non linear partial differential equations of the motion of concentric rotor in finite length large gap annular flow are derived and solved by means of numerical method. Thus the dynamic coefficients of the concentric rotor immersed in finite length large gap annular flow are studied by means of the numerical method. The effects of stator/rotor wall roughness, inlet pressure, length diameter ratio and inlet pre rotation on the rotor dynamic coefficients are also discussed. The results show that these effects are the combined effects of the fluid inertial effect, friction dissipative effect, swirling effect, and Lomakin effect.