Design And Research Of Sound Source Used For The Acoustic Testing System Of Porous Metal Materials

Porous metal material is excellent performance of sound absorption and noise reduction properties are widely used in industrial and engineering field,acoustic performance of porous metal materials under extreme environlent research is more and more attention.This paper is based on acoustic performance of porous metal material test platform requirements,design and build the sound system,using COMSOL software simulate acoustic performance of loudspeakers about the core component of sound source system.First of all,this paper summed up the basis of acoustic theory for the sound source design required,including basic concepts,acoustic equation of acoustic wave ideal medium,ideal sound and acoustic field model on the adverse effect of the sound source.Explain the sound mechanism of different kinds of sound source,and analyzes in detail the structure and principle of horn-type loudspeaker.Secondly,based on the electrnc-force-acoustic analogy method,this paper set up lumped parameter model of the speaker system to simplify,electrical parts and vibration of the equivalent circuit is set up respectively.Using COMSOL software "lumped mechanical system interface" simulate and analyse lumped parameter model,has earied on the preliminary study on characteristics of the speaker.Finally,according to the sound pressure level design requirements,this paper complete thehom-type loudspeaker magnetic circuit components selection,design for structural and vibration.Using COMSOL software of "magnetic field,mf","solid solid mechanics" and "acoustic pressure and frequency domain,aepr" three modules all coupling simulation model is established,simulation was carried out on the speaker magnetic circuit and acoustic properties.Secondly has carried on the sound pressure level test,the design is verified by comparison superiority of sound source system.According to the design of the sound system,set up corresponding porous metal material acoustics performance test platform.We set up comparison test with the BSWA SW422 acoustic comparison testing system,in 96 db and under the condition of different cavity backing to the thickness of 20 mm,the porosity of 85%nickel foam materials for sound absorption performance test.By comparing this paper build test platform test curve and the BSWA SW422 acoustic test system test curve,verified the accuracy of the test platform,the paper is also further venfied the validity and accuracy of the sound source designed system based on the porous metal material the acoustic performance tests.And using this test platform tests sound absorption performance of different thickness(10 mm,20 mm,30 mm)and different porosity(85%,90%,95%)of nickel foam material,and tests the sound absorption performance of nickel foam under different sound pressure level.