Development of a Digital Image Projection Technique to Measure Wind-Driven Water Film Flows

Abstract

Digital fringe projection (DFP) profilometry has been widely used to generate threedimensional (3D) surface information. In this work, a novel 3D shape measurement system based on DFP technique is proposed for accurate and quick thin film/rivulet flow measurement. The key concept of the technique is making use of digital image correlation (DIC) algorithm to direct calculate the projected grid points' displacements. In comparison to fourier transformation based DFP system, it gives more accurate measurement result without rigid image quality requirement. This technique was applied to characterization of wind-driven thin film/rivulet flows that were formed in an open circuit wind tunnel. The film thickness and surface wave frequency had been evaluated for variety of wind speeds and flow rates. The results show that this technique successfully revealed the dynamic motion features of thin film flows.

Characteristics of secondary droplets produced by the impact of drops onto a smooth surface

“…In the past few decades, many flight accidents caused by aircraft ice accretion have occurred in the world. The study of impingement and icing of supercooled droplets has been accompanied by the development of the aviation industry for a long time and has attracted more and more attention [6][7][8].…”

Experimental Research on the Fluctuation Characteristics of Water Film Driven by Wind

“…Cherdantsev et al [10] studied the process of the water film flow on the surface of a horizontal flat plate under the action of high-speed airflow shear and proposed the three-dimensional structure of the water film surface fluctuations and its possible mechanism. Zhang et al [11] investigated the average thickness of the water film at different wind speeds based on the digital image projection (DIP) technique and studied the reflux phenomenon of the water film on the airfoil surface [12,13]. Chang et al [14] used a planar laser-induced fluorescence method to analyze the thickness and fluctuation characteristics of the water film.…”