摘要

Fountains occur in both natural and industrial environments as pyroclastic eruptions, smokestacks from industry, and brine water discharges into the ocean from a desalination plant. Tomographic particle image velocimetry (TPIV) measurements were taken of a regime of turbulent fountain flows. A saline solution was injected through a circular exit into the bottom of a reservoir of a water-ethanol solution. As TPIV is an optical technique relying on the reconstruction of particle intensities based on the lines-of-sight from the cameras pixels, the refractive indices of both solutions were matched. The TPIV analysis revealed qualitative and quantitative features of large-scale structures in forced fountains during initialization and in a fully developed state. The initialization showed various stages of a fountain's life, with an initial burst that detaches from the jet region of the fountain observed, followed by stagnation, and then collapse of the fountain. For fully developed fountains, the jet and annular reverse regions were captured, and the turbulence intensity revealed the Fr number dependence on flow behavior.