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Image Processing Techniques for Velocity Estimation in Highly Aerated Flows: Bubble Image Velocimetry Vs. Optical Flow

Author(s): D. B. Bung; D. Valero

Linked Author(s): Daniel B. Bung, Daniel Valero Huerta

Keywords: No keywords

Abstract: Measuring of flow velocities in aerated flows is known to be difficult in physical models. Application of classical anemometers or ADV probes is limited to low air concentration. Thus, highly aerated flows are commonly investigated by use of intrusive needle probes (conductivity or optical fiber) which allow determination of both, air concentration and velocity, as well as related parameters (e.g. bubble chord lengths and turbulence). In the recent past, non-intrusive image processing techniques have gained more attraction. In the present paper, Bubble Image Velocimetry and Optical Flow methods are applied to aerated stepped spillway flows using high-speed cameras with different resolution to highlight capabilities and limitations of both methods. Results show that Optical Flow is capable to give results of at least the same accuracy as Bubble Image Velocimetry. A higher image resolution enhances the quality of the results. The dense velocity information being obtained by Optical Flow may help to carry out investigations on turbulence in future.

DOI:

Year: 2016

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