超声衰减谱法测量泥沙粒度分布

利用超声衰减谱的测量,可以获得泥沙中颗粒粒度分布信息。采用超声耦合相模型和Bouguer-Lambert-Beer-Law散射模型的叠加描述河流泥沙中超声衰减行为,宽频超声换能器测量得到2MHZ至7MHZ间泥沙声衰减谱,结合独立模式的最优正则化反演算法,获得了体积浓度4.5%,12.4%,15.8%下泥沙的颗粒粒度分布。结果表明,超声衰减谱法能在体积浓度直至15.8%的高浓度条件下获得泥沙颗粒粒度分布,并且测量得到的平均粒度受浓度变化影响较小。将超声法测量结果与光学图像法测量结果相比较,两种测量方法得到的结果较为吻合。

Sediment size distribution measurement with ultrasonic spectrum method

The attenuation spectrum of ultrasonic waves through the slurry may provide the information about particle size distribution.Combined with the inverse algorithm of the optimum regulation technique,the particle size distributions of sediment under different volumetric concentrations are obtained according to the attenuation prediction of Coupled-phase model plus Bouguer-Lambert-Beer-Law scattering model and experimental attenuation spectrum at frequency ranges from 2MHz to 7MHz.The results show that the ultrasonic spectrum method is suitable to characterize the sediment with the condition of high concentration.The change of concentration is of little influence to the measured number mean diameter.The measurement results of ultrasonic attenuation spectrum method agree well with the optical image measurement results.