关键词: 计算流体力学, 低速预处理, 旋翼, 舰船, 非定常流动

Abstract: Steady low speed preconditioning is of poor convergence in dual-time iterations, and unsteady low speed preconditioning automatically reverts back to no preconditioning in numerical simulation of rotor aerodynamic interaction. To overcome these problems, we conduct an order analysis to blend the steady and unsteady low speed preconditioning eigenvalues matrices based on the unsteady low speed preconditioning framework. A new Blend low speed preconditioning method is developed from altering the dissipation formulation using this matrix.The unsteady flow around the circular cylinder, unsteady rotor-fuselage aerodynamic interaction in the helicopter forward and coupling ship/rotor flowfields are simulated to validate the proposed method. The numerical results indicate that the proposed method can solve the problem of automatical reversion of unsteady low speed preconditioning back to no preconditioning, and can improve significantly convergence of steady low speed preconditioning.

Key words: computational fluid dynamics (CFD), low speed preconditioning, rotor, ship, unsteady flow