Research On Vibration Source Analysis, Noise Prediction, Vibration And Noise Control Of Marine Separator

The electromechanical equipment is the source of vibration and noise when the ship isrunning. The rotating machinery is one of the most common electromechanical equipment onboard, so the control of its noise and vibration is drawing more and more attention. Low-noiseDesign is the basic way to control the noise and vibration of the electromechanical equipment,with vibration source analysis and noise prediction as its key issue.In this thesis, the method of simulation combined with experiment is taken into theresearch of KYDR203CD-23Marine Separator. Firstly, three-dimensional solid model iscreated according to physical structure,then discrete the modal. Finally, an accurate finiteelement modal is constructed based on test modal results.The condition number of frequency response function between the equivalent excitationpoint and response point is calculated to choose the appropriate response points in the loadidentification. Combined with the measured vibration acceleration response, the least squaresmethod in the frequency domain is used in dynamic load identification, and the correctness ofthe identification results is verified by the other response points which are not involved before.Add the identified load results to the structure again to calculate its forced response. Usingthis results, structure radiated noise prediction is calculated with boundary elementmethod,this provides an important basis for the low-noise design of the electromechanicalequipment.Accroding to the results including modal character,dynamic spectrum,and the coherencebetween vibration and noise，effective methods which are different from the traditional wayof changing the structures are found to control the noise and vibration of marine oil separator.（1）Installed isolator at the foot of the machine to change the connection to the earth, that ischanging rigid mounting to flexible installation.（2）According to the signal coherenceprinciple, the area which contribute more to Airborne noise is found,and artificial damping isused in this paper to reduce the chamber noise（3）Slider-type vibration absorber is designedfor the single-line spectrum. The thesis have taken experiment to verify these programs andget a good effect of vibration and noise reduction.In the thesis, the analysis of Modal analysis, dynamic load identification, radiated noiseprediction and noise and vibration control are carried,.Preliminary summarized the improved design flow of the electromechanical equipment with serious vibration. The work provides auseful reference for low-noise design of the electromechanical equipment.