探测频率对多频声学测沙技术测量误差的影响

为了探究多频声学测沙技术在高泥沙浓度水流中应用的可行性以及探测频率对测量误差的影响，以黄河典型泥沙浓度和粒径剖面数据为基础，应用能量比反演算法，建立反演仿真模型，开展误差分析以及测量误差关于测量频率的敏感性分析.结果显示，声学测沙技术在使用某些与粒径相关的频率测量时，可以明显减少测量误差，具有应用可行性.基于此低误差测量结果，提出优选频率的概念，分析得出，相对浓度而言，优选频率与泥沙粒径的相关性更高.根据是否考虑粒子散射衰减，分别计算出高、低泥沙浓度水流中优选频率与粒径的关系曲线.两组曲线变化趋势一致，但由于粒子散射衰减，高泥沙浓度水流中优选频率整体取值较小.

Measurement error due to frequency selection in multi-frequency suspended sediment measurement system

A simulation model was built to inverse the sediment concentration and particle size from acoustic backscattering signal, based on the typical sediment concentration and size distribution measured from Yellow River, in order to analyse the feasibility of multi-frequency acoustic measurement and the causes of measurement error due to the frequency selection in high concentration sediment-laden flow. The measurement error and its relationship with measuring frequency were analysed. Results indicate that the inversion error may be reduced if frequency can be properly decided. The particle size is a more important factor than concentration when choosing better frequency for measurement. The relationship of frequencies versus particle size in high concentration and low concentration cases was respectively calculated. Results accord with each other and this paper prefers to use lower frequency in condition of high concentration due to scattering lose.