The thesis addresses the development and application of a visualization method for measuring the water surface level in a physical hydraulic model created using 3D printing. The main goal was to replace traditional point-based measurement techniques with a more efficient process based on computer video analysis. An experimental channel in the laboratory of the Chair of Fluid Mechanics (University of Ljubljana, Faculty of Civil and Geodetic Engineering) was used, allowing the insertion of different weir shapes, e.g. sharp-crested, trapezoidal, broad-crested, and ogee. The weirs were designed and 3D printed using PETG material. LED lights were used to illuminate the water surface, which was detected through color contrast and image binarization. A custom procedure was developed in Wolfram Mathematica to automatically determine the water surface height from video recordings. This allows for straightforward analysis of how flow rate and upstream water level affect the water surface profile. The results were compared with traditional point gauge measurements and showed good agreement. The analysis revealed that the water surface profile is significantly influenced by the weir height, flow rate, and tailwater. As the flow rate increases, the water level at the dam rises and the wave moves downstream. With a higher crest, the water surface becomes more stable. The shape of the weir has a strong effect on the water surface profile at lower flow rates. The method reliably detects these phenomena and allows non-intrusive vizualization–based measurements.
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