Bubble aspect ratio and velocity measurement using a four-point fiber-optical probe

We propose a new algorithm to estimate the bubble’s aspect ratio and its velocity from the time series obtained by a four-point fiber-optical probe. The accuracy and the robustness of the algorithm is analyzed for bubbles with an equivalent diameter of 2–4 mm using both synthetic and experimental data. The experimental data is obtained by means of stereoscopic high-speed imaging. The three dimensional shape of the bubble is reconstructed from a set of stereoscopic contour lines.