基于几何平均声压的声强计算的误差分析

Error Analysis Based on Sound Power Calculating via Geometrical Average Sound Pressure

采用p p法计算声强时 ,需要用两个传声器测得的声压的均值代替被测点的平均声压 ,用两声压进行一阶差分来间接获得声振速。声压平均一般基于算术平均算法 ,分析发现 :在高频区误差较大。针对声场大多呈非线性的特点 ,提出了应用几何平均计算声压的方法。并以平面声源、单极子、偶极子三种声源为例 ,对基于这两种计算声压的方法得到的声强误差进行了对比分析 ,结果表明

When calculating the power of sound source using the p p strategy, the sound pressure obtained via two microphones should be averaged as the average sound pressure of the estimated point, and the difference of the two sound pressures acts as the sound vibrate speed. Normally the average of the sound pressure is based on arithmetical average. Study shows that the error is much bigger in high frequency, and most of the sound fields are nonlinear, so the method of calculating the sound pressure based on geometrical average is developed. The monopole source, dipole source and quadrupole source are selected as the research objects respectively, and the sound power errors obtained via the two average methods have been studied. Results show that in high frequency, the sound error obtained via geometrical average is less than that calculated via the arithematical average method.