Schlieren Image Velocimetry applied to EHD flows

R. SOSA; E. ARNAUD; E. MEMIN; G. ARTANA

Buenos Aires, Argentina

Simposio; International Symposium on Electrohydrodonamics (ISEHD); 2006

Facultad de Ingeniería - UBA

In this paper, we address the problem of estimating the motion of fluid flows driven by electrohydrodynamic forces. The fluid motion is visualized through a Schlieren technique. Such a technique is well known in fluid mechanics as it enables pictures of the flow without the use of strange tracers. As the images exhibit in general very low photometric contrasts, classical motion estimation methods based on the brightness consistency assumption (correlation-based approaches, optical flow methods) are rather inefficient. This work aims at proposing a sound energy based estimator dedicated to these images. The energy function to be minimized is composed of (a) a data term describing the fact that the observed luminance is linked to the gradient of the fluid density and (b) a specific div curl regularization term. The relevance of our estimator is demonstrated on air flows forced with plasma actuators.