Three-dimensional (3-D) velocity field reconstruction of oscillatory thermocapillary convections in a half-zone liquid bridge with a radius of O (1 mm) was carried out by applying 3-D particle tracking velocimetry (PTV). Simultaneous observation of the particles suspended in the bridge by two CCD cameras was carried out by placing a small cubic beam splitter above a transparent top rod. The reconstruction of the 3-D trajectories and the velocity fields of the particles in the several types of oscillatory-flow regimes were conducted successfully for sufficiently long period without losing particle tracking. With this application the present authors conducted a series of experiments focusing upon the collapse and re-formation process of the PAS by mechanically disturbing fully developed PAS.
Research Containing: Oscillatory thermocapillary convections
Various flow patterns in thermocapillary convection in half-zone liquid bridge of high prandtl number fluid
Various flow patterns induced by a thermocapillary-driven convection in a half-zone liquid bridge of a high Prandtl number fluid (Pr = 0(10)) far beyond the critical condition were investigated experimentally. After the onset of oscillatory convection, one can observe several types of flow patterns with increasing a temperature difference between the both end surfaces of the bridge. The flow patterns were categorized through flow visualization, measurement of surface temperature variation and reconstruction of the pseudo-phase space.
Three-dimensional (3D) reconstruction of a unique particle motion in oscillatory thermocapillary convections in a small-sized half-zone liquid bridge with a radius of O (1 mm) was carried out by applying 3D particle tracking velocimetry (PTV). By placing a small cubic beam splitter above a transparent top rod, simultaneous observation of the particles in the bridge by use of two CCD cameras was realized. Reconstruction of the 3D trajectories and the particle velocity fields in several types of oscillatory flow regimes was conducted successfully for a sufficiently long period without losing particle tracking.