Research On Sound Absorption Properties And Experimental Platform Design Of Porous Metal Materials Under High Temperature And High Acoustic Pressure

In recent decades,ultra-light porous metal materials have developed rapidly as a new type of structurally versatile material.Porous metal materials are light weight,high strength and toughness,easy to process,and have energy absorption,noise reduction,noise reduction,and electromagnetic frequency.Closed,thermal insulation,corrosion resistance,etc.,can be used as structural materials,and can also be used as a functional material for special occasions such as high-temperature heat dissipation,vibration damping,and the like.In view of its good sound absorption and vibration reduction advantages,porous metal materials have great application prospects in the sound absorption and noise reduction in extreme environments.For example,lightweight porous materials that can withstand high temperatures,corrosion resistance,and high stiffness,as well as sound-absorbing and heat-conducting properties,are used in gas explosion-proof,aero engine noise-reducing acoustic linings,armor protection,and the like.In addition,the sound pressure levels emitted by modern jet engines,gas turbines,and internal combustion engines can reach 160 dB to 180 dB.Under such high acoustic pressure acoustic wave excitation,the assumed linear conditions for studying the acoustic properties of porous metal materials are no longer valid.In order to meet the sound absorption and noise reduction design requirements under the high sound pressure level noise environment,systematic theoretical and experimental studies must be conducted on the sound propagation laws,energy dissipation mechanisms and nonlinear sound absorption characteristics of porous metal materials under high sound pressure.Therefore,it is of great practical significance to study the sound absorption characteristics of porous metal materials under extremely complex environments such as high temperature,high sound pressure,and strong airflow.It is of great value to China's new equipment,especially large-scale high-energy-consuming equipment such as light weight,energy saving,consumption reduction,and noise control.Firstly,based on the experimental research on the acoustic properties of porous metal materials under normal temperature and pressure,the metal foam copper and porous sintered copper were used as experimental objects to study their sound absorption characteristics under high temperature and high sound pressure conditions.Second,the high-temperature sound-absorbing performance testing device for porous metal materials was designed based on the principle of dual-microphone transfer function method.The surface temperature of the test bench was tested and compared with the finite element software COMSOL Multiphysics model under the same experimental temperature conditions.The results show that the theoretical model and experimental results have certain rationality,reliability and accuracy,and then the sound absorption properties of the porous metal materials are measured and acoustically analyzed at room temperature and in a constant temperature field(100? to 700?).deal with.Thirdly,analyze the results of variation of sound absorption coefficient of porous metal material with incident frequency,cavity,temperature,and sound pressure level,summarize the variation law of sound absorption coefficient under high temperature effect,and carry out experimental results and problems in the experimental process.Analyzed and proposed suggestions for test methods and experimental equipment.Fourth,using a self-designed and constructed porous metal material experimental testing device with high sound pressure and sound absorption performance to verify the sound absorption performance test platform for porous metal materials under high sound pressure level(>120dB)environment measuring.