The Mechanism Study Of Elastic Wave Propagation In Porous Media

Elastic wave propagation in porous media is a branch of applied acoustics. The study of porous media has important application value. In this paper, we first discussed the spherical and ellipsoidal pore compressibility according to the definition. Then we deduced the equivalent modulus. Finally, this paper calculated the wave velocities along with the change of frequency and porosity. The results included the following.In this paper, the spherical pore and ellipsoidal pore compressibility have been calculated. The spherical pore compressibility is related to fluid type, frequency and spherical size. The ellipsoidal pore compressibility is not only related to fluid type, frequency and ellipsoidal size, also related to the direction of press. The compressibility decreases with frequency and both in low and high frequency it tends to be constant.This paper deduced the equivalent modulus of saturated porous media and the bulk modulus and young's modulus have been discussed. The bulk modulus increases with frequency and decreases with porosity. The young's modulus also increases with frequency and decreases with porosity. The bulk modulus and young's modulus are between the lower and upper bounds compared to the Hashin-Shtrikman bounds which are the best.The wave velocities of saturated porous media have been calculated. The velocities increase with frequency and decrease with porosity. Both in the low and high frequency velocities tend to be constant. With the same porosity, the velocities containing ellipsoidal pores are slower than spherical pores. The greater the modulus difference between solid and fluid, the larger the dispersion takes place. The dispersion about p-wave is larger compared with s-wave.