外部轴向激励作用下螺旋桨轴承力非定常变化特性数值研究

Numerical Study on Unsteady Variation Characteristics for Bearing Forces of a Propeller with External Axial-Excitation

关键词:  非定常轴承力  轴向激励  激励频率  螺旋桨  动网格方法

Key words:  Unsteady bearing forces  Axial-excitation  Excitation frequency  Propeller  Dynamic mesh method

摘要:

为了研究外部轴向激励作用对螺旋桨非定常轴承力的影响，基于动网格方法和RANS湍流模型相结合的数值方法，对螺旋桨进速系数0.833，转速10Hz条件下，外部轴向激励作用和无激励作用时三叶常规螺旋桨轴承力的非定常变化特性进行了分析。结果表明，相比于无激励作用，外部轴向激励作用会使螺旋桨非定常轴承力的频域上新增一个显著的响应分量，其频率与激励频率始终保持一致；若保持激励幅值不变，新增响应分量的幅值会随着激励频率的增大而增大；若保持激励频率不变，新增响应分量的幅值会随着激励幅值的增大而增大，且两者存在着系数为0.015的正比关系；外部轴向激励作用下螺旋桨的压力场和涡量场的分布与无激励作用时相比仅在细节上存在不同程度的差异。

Abstract:

In order to investigate the effects of the external axial-excitation on the unsteady bearing forces of a propeller，based on the dynamic mesh method，combined with RANS turbulence model，the unsteady variation characteristics of the bearing forces of a three-blade conventional propeller were analyzed under the conditions of advance coefficient 0.833 and rotational speed 10Hz of the propeller with the external axial-excitation and no excitation. The results show that a significant responding component is produced in the frequency domain of the unsteady bearing forces of the propeller under the action of the external axial-excitation，compared to a no excitation case. Its frequency is permanently equal to the excitation frequency. If the amplitude of the external axial-excitation is constant，the amplitude of the responding component will increase with the growth of the excitation frequency. If the excitation frequency is constant，the amplitude of the responding component will increase proportionally to the excitation amplitude with the coefficient 0.015. The distribution of the pressure field and the vorticity field only differ in minor aspects for the external axial-excitation cases and no excitation cases.