In order to using power sound wave increase permeability of coal, rules of attenuation of sound wave in coal should be studied. In this paper, characteristic and mechanism of attenuation of sound wave in coal was rese...In order to using power sound wave increase permeability of coal, rules of attenuation of sound wave in coal should be studied. In this paper, characteristic and mechanism of attenuation of sound wave in coal was researched according to acoustic theory and attenuation coefficients was estimated by acoustic parameter of coal. The research results show that the main attenuation mechanism of sound wave in coal is absorption attenuation and scattering attenuation. The absorption attenuation includes viscous absorption, thermal conduction absorption and relaxation absorption. Attenuation coefficient of sound wave in gaseous coal is 38.5 Np/m. Researches on attenuation characteristic of sound wave will provide the theoretical basis for power sound wave improving permeability of coal and accelerating desorption of coal bed gas.展开更多
The attenuation regularity of explosion stress waves in damaged rocks is discussed according to physical and geometric attenuation of waves in this paper. The relation between numerical decrement and damaged parameter...The attenuation regularity of explosion stress waves in damaged rocks is discussed according to physical and geometric attenuation of waves in this paper. The relation between numerical decrement and damaged parameter is given and the results have an important significance to design and control blasting effect accurately in a concrete rock.展开更多
文摘In order to using power sound wave increase permeability of coal, rules of attenuation of sound wave in coal should be studied. In this paper, characteristic and mechanism of attenuation of sound wave in coal was researched according to acoustic theory and attenuation coefficients was estimated by acoustic parameter of coal. The research results show that the main attenuation mechanism of sound wave in coal is absorption attenuation and scattering attenuation. The absorption attenuation includes viscous absorption, thermal conduction absorption and relaxation absorption. Attenuation coefficient of sound wave in gaseous coal is 38.5 Np/m. Researches on attenuation characteristic of sound wave will provide the theoretical basis for power sound wave improving permeability of coal and accelerating desorption of coal bed gas.
文摘The attenuation regularity of explosion stress waves in damaged rocks is discussed according to physical and geometric attenuation of waves in this paper. The relation between numerical decrement and damaged parameter is given and the results have an important significance to design and control blasting effect accurately in a concrete rock.
