Research On The Noise Reduction Technology Of Guide Hood Based On Groove And Leading Edge Optimization

For modern ships,the flow-induced noise of the flow diverters is critical to the signal-tonoise ratio of sonar systems,directly affecting the ship’s detection and combat capabilities.However,under certain sailing conditions,optimizing the shape and local details of the flow diverters can greatly reduce the impact of flow-induced noise.This paper proposes a method for optimizing the flow diverter model based on groove flow control and front edge length optimization,reducing its flow-induced noise.Regarding the complex and unstable flow phenomena on the surface of the flow diverters,this paper takes a model of a certain ship’s flow diverter section with front and rear processing as the research object.The flow field of the flow diverter model was numerically calculated,and the numerical calculation results of the flow field were comprehensively analyzed.The boundary layer separation,turbulence spot generation,and vortex structure development near the maximum cross-section of the flow diverter are all reasons for flow-induced noise.Based on this,the surface pressure and vortex structure changes of the model after applying the groove flow control were analyzed.The flow-induced noise of groove structures with different widths,depths,and spacing were calculated.Additionally,different front-edge length optimized models were proposed to address the boundary layer separation phenomenon.The changes in the entire flow field of the optimized model were analyzed,and the flow-induced noise and cavitation characteristics of different front-edge length optimized models were calculated.Finally,the best noise reduction model under two measures was determined.Finally,experimental models of the original and optimal noise reduction models were designed and manufactured.Measurement tests of hydrodynamic noise were conducted in a gravity water tank using the reverberation method to evaluate the noise reduction effect of the optimal model.The experimental results indicate that Model III with optimized front edge length has good noise reduction effect at three different operating conditions of 2.46 m/s,3.66m/s,and 4.62 m/s.In the frequency range of 500 Hz to 2000 Hz,the total radiated sound power level is reduced by more than 4 d B.The best noise reduction effect is achieved at a flow rate of2.46 m/s,with a reduction of 6.42 d B.The research findings of this paper provide new ideas for the hydrodynamic noise control of flow deflectors and serve as a reference for the study of lownoise flow deflectors.