The numerical simulation is used in this work to study the nearfield radiation pressure of a piston projector, the smooth effect on the pressure field by using a 'big' receiver and the influence of the nearfie...The numerical simulation is used in this work to study the nearfield radiation pressure of a piston projector, the smooth effect on the pressure field by using a 'big' receiver and the influence of the nearfield and in the transition region on measurement of sound absorption coefficient. The result indicates that the big error would appear when using usual absorption coefficient measurement method. According to the reason causing the error, the method eliminating nearfield effect (MENE) is proposed and some digital results are given for a / λ= 3, 9 and b = 0, 0.5a, a (a and b are the transducer and receiver radii respectively). The calculation results show that the method not only widens measurement range in nearfield, but also gives accurate results.展开更多
文摘The numerical simulation is used in this work to study the nearfield radiation pressure of a piston projector, the smooth effect on the pressure field by using a 'big' receiver and the influence of the nearfield and in the transition region on measurement of sound absorption coefficient. The result indicates that the big error would appear when using usual absorption coefficient measurement method. According to the reason causing the error, the method eliminating nearfield effect (MENE) is proposed and some digital results are given for a / λ= 3, 9 and b = 0, 0.5a, a (a and b are the transducer and receiver radii respectively). The calculation results show that the method not only widens measurement range in nearfield, but also gives accurate results.
