Study On Propeller Sound Radiation Of Submarine-Propeller Coupling

As a common propulsion device of all kinds of ships,the analysis of its performance is very important.In the military field,the contribution of propeller to ships can not be ignored,especially for submarines with high stealth performance requirements.As an important noise source,the analysis of propeller noise performance is becoming more and more important.This paper is based on the highly skewed propeller and SUBOFF submarine,using Fluent and LMS Virtual.Lab software,the sound radiation of propeller coupled with boat propeller is studied by lab software.Firstly,based on the existing data and theory,this paper adjusts the parameters of a highly skewed propeller,improves and designs a seven blade highly skewed propeller,and carries out the open water experimental numerical simulation with FLUENT software.Before that,the accuracy of the numerical simulation is verified with DTMB P4119 propeller,and SST k-ω is used for fluid calculation.Based on the SST k-ω turbulence model and MRF method,the main hydrodynamic parameters of the highly skewed propeller under each advance coefficient are analyzed,and the flow field around the highly skewed propeller is analyzed.Then,the wet mode of the highly skewed propeller is analyzed.The acoustic solid coupling method is used in the ANSYS Modal Acoustic module,and the accuracy of this method is verified and calculated;Then the frequency range of possible resonance and the main forms of vibration of the propeller are obtained through the analysis of the highly skewed propeller;Considering the influence of rotation on modal analysis,relevant calculations are carried out;Combined with the wet mode,the response of the highly skewed propeller excited at different positions of the blade is analyzed,and the excitation position and frequency prone to higher horizontal harmonic response are obtained.Then use Fluent and LMS Virtual.Lab software analyzes the noise of propeller working alone under different advance coefficients.Combined with the experimental results of others,the acoustic calculation is verified,and the accuracy of the software is very excellent;The large eddy simulation turbulence model is used for fluid transient calculation,and the fluid calculation results are imported into LMS Virtual.Lab software in CGNS format,the noise of propeller working alone with advance coefficient J=0.45 is analyzed.There is an obvious peak value of sound pressure level in the plane direction of propeller disc,which needs to be considered emphatically;The propeller noise under each advance coefficient is compared.The noise of propeller working alone has little correlation with the advance coefficient.Finally,the flow field of submarine with propeller under different working conditions is calculated by SUBOFF submarine model and highly skewed propeller model.There are obvious high-pressure areas in the bow,console enclosure,stern rudder and propeller areas of submarine,and the pressure variation gradient is very large;After that,the sound radiation of the propeller coupled with the submarine propeller under different working conditions is analyzed,with emphasis on the sound radiation of the subma rine under the condition of full speed forward;Finally,the noise results are compared and analyzed according to different working conditions.