基于B超成像的泥沙起动流速测量方法

床面上泥沙颗粒的起动测量一直是泥沙运动规律研究的难题。为此,提出了一种基于B超成像技术的泥沙起动流速测量方法。在模型试验水槽中,该方法利用B超仪获取水下地形及其附近粒子的运行图像,通过图像处理技术分析统计床面附近运动粒子的成像光斑个数,并分析其与流速之间的关系。结果表明,B超成像光斑个数在泥沙起动过程中存在一个突变过程,且该突变过程与泥沙起动运动相对应,可用来判定泥沙起动及其对应的起动流速,并利用该流速下的床面地形变化验证了该方法的正确性。该方法具有无扰动无干扰、适合于清水和浑水、易于实现自动化测量的特点。

A method of measuring sediment incipient velocity based on B-scan ultrasound imaging technique

The measurement of the incipience of sediment particles on the riverbed has been a difficult problem in sediment transport research. For this reason, this paper puts forward a method of measuring sediment incipient velocity based on B-scan ultrasound imaging technique. This method uses B-scan ultrasound imaging device to obtain the underwater topography and ultrasonic moving images of the nearby particles in the model water channel. The image spots of the moving particles near the riverbed are analyzed and counted by means of image processing techniques. The relationship between flow velocity and particle spots is also analyzed. The result shows that particle spots have a mutation during the process of sediment incipient motion, which is corresponding to the sediment incipient motion. It can be used to measure sediment incipient and the corresponding incipient velocity. The measured incipient velocity is verified by changed topographic lines of riverbed. This method is free from flow disturbance and interference, suitable for both clear and muddy flow water and easy to realize automatic measurement.