Author(s): D. B. Bung
Linked Author(s):
Keywords: Stepped spillway flow; Air-water flow; Non-intrusive measuring methods; Bubble image velocimetry; Ultrasonic sensors
Abstract: For hydraulic design of stepped spillways, knowledge of flow properties as flow depth and velocity of the air-water mixture is essential. Generally, these parameters are measured on largescale models by use of an intrusive probe (i.e. double-tip conductivity or fiber-optical probe) and scaled to prototype dimensions. In this paper the capability and limitation of non-intrusive measuring devices are analysed by comparison with a large model data set measured with a double-tip conductivity probe in skimming flow regime. In fact, flow depths are measured with an ultrasonic sensor and velocity fields are determined by use of a modified high-speed PIV method (Bubble Image Velocimetry). The results indicate that non-intrusive devices may be applied for a first estimation of flow properties with sufficient accuracy. The flow field above the pseudo-bottom and within the cavity of the steps can be visualized in high resolution.
Year: 2011