全附体潜航器螺旋桨桨叶损伤故障辨识机理

全附体潜航器智能故障诊断需要以完善的故障数据集为基础,而有些工况下典型故障数据很难获得,可通过数值仿真得到.基于流体基本原理,求解三维非定常雷诺平均Navier-Stokes方程和湍流封闭方程,获得均匀来流条件下桨叶损伤对全附体潜航器扰动流场与力矩波动的影响.结合场强分析归纳出桨叶损伤特征与其流场演化、流体动力学特征之...

Identification Mechanisms for Damage Characteristics of Fully Appendage Submarine Propeller

The intelligent fault diagnosis should be based on a perfect sample database,which must contain enough sampled data obtained from different working conditions. But many faults,especially in some special conditions,cannot be gained by experiments or practical samplings,so they need to be accumulated through numerical simulations. Based on the basic fluid principle,the influence of blade damage on the flow field and moments fluctuation of fully appendage underwater vehicle under uniform flow is obtained by solving the three-dimensional unsteady Reynolds average N-S equations and turbulent flow closed equations. The coupling mechanism between blade damage characteristics,propulsion efficiency and hull dynamics characteristics is concluded by field strength analysis. The results show that the pressure plays a leading role on total moment compared with the viscous force. The fluctuation of pressure moment can be divided into a large-amplitude low-frequency oscillation and a small-amplitude high-frequency oscillation. The frequency for the former oscillation mostly depends on the detached vortex frequency,and the frequency for the high frequency oscillation is consistent with the propeller rotation frequency. For the large amplitude oscillation of pressure moment coefficient,the thrust eccentric position of blade determines the offset of the balance line relative to the zero position. The phase difference between pitch and yaw moments reflects the symmetry of blade,and the smaller the phase difference is,the stronger the symmetry of blade will be. The blade damage types are predicted from the change of viscosity moment.