基于表面积分法的掘进巷道声场特性数值分析

Numerical analysis on acoustic field characteristics of excavation roadway based on surface integration method

基于表面积分法,建立了掘进巷道声能密度及声压级数学模型和微元网格模型,编制并运行了Matlab程序对掘进巷道长空间的噪声声场特性进行了数值计算,分析了接收点距离,吸声系数和曲面半径等对巷道声场的影响。结果表明:半圆拱形横截曲面的划分平面数为奇数时产生的散射声压级比平面数为偶数时产生的散射声压级大;巷道噪声声压级随接收点离开声源的距离呈曲线衰减态势且衰减速度逐渐变慢;巷道岩壁吸声系数增大时,声压级衰减速度随接受点离开声源距离的增加而变慢;巷道横截曲面半径增大时,掘进工作面最大声压级减小,声压级衰减速度随离开声源距离的增加而减慢。

Based on surface integration method,sound energy density of the excavation roadway,mathematical model of the sound pressure level and model of micro-element mesh were established,and sound field characteristics of long space in excavation roadway was analyzed and calculated by using Matlab software.Moreover,the influence of roadway sound field caused by receiving point distance,sound absorption coefficient and the radius of curved surface and so on were analyzed.The study results indicate that as the divided plane numbers of semicircle arched curved surface in cross section is odd numbers,the scattering acoustic pressure level is bigger than that of even numbers;as the receiving point is far from sound source along the direction of excavation roadway,sound pressure level of excavation roadway attenuates in the shape of a curve,meanwhile the speed of attenuation becomes slower;as the absorption coefficient of roadway rock increases,the speed of attenuation gets slower along distance;as the radius of curved surface of excavation cross section increases,maximum sound pressure level not only decreases,but also decays with a slow rate.