| Underwater submersibles play a very important role as tools for underwater operations or as national defense weapons.With the development of marine strategy,various indicators of underwater vehicles must be improved accordingly,and reliability is particularly important.The propeller is one of the core components of the underwater vehicle.As an important part of the propulsion device,its reliability and safety must be very high.The reliability of the underwater vehicle propulsion device has gradually grown from an index to an important research direction.The propeller sucks the forward flow and pushes it out from the rear to generate thrust,which pushes the submersible forward to maintain a certain speed.The propulsion device is closely linked to the stability,reliability and safety of the submersible.Especially in military underwater submersibles,the stability,reliability,and safety of the propulsion device directly affect the navy’s combat effectiveness;if in a war,the situation will be greatly affected.However,under the sea surface,the propeller will be accidentally damaged due to various reasons such as seaweed entanglement and hard object collision.Therefore,timely diagnosis of propeller failure plays a vital role in defending my country’s waters.Based on CFD numerical calculations,this paper calculates two different degrees of single-blade loss and two-blade loss in different relative positions,and collects the pulsating pressure at a specific position of the propeller appendage and the lateral direction of the propeller in the y direction and z direction.Force coefficient.Research the eccentricity of pressure distribution according to the characteristics of velocity,pressure distribution and pulsating pressure signal waveform in the flow field;using spectrum analysis method to study the relationship between the magnitude of the fundamental frequency component and the octave frequency component in the pulsating pressure spectrum and the relationship between the propeller loss;Wavelet analysis is carried out on the lateral force coefficient of the propeller,the singularity of the lateral force coefficient signal is studied,and the wavelet singularity theory is combined for fault detection.Finally,the purpose of detecting the existence of the fault and diagnosing its type is achieved. |
