Droplet entrainment and size distributions from flow separation over a melting paraffin slab
Year: 2025
Type: article
Abstract: In this study, the effects of separated flow over a melting paraffin slab on atomization is considered. Experiments are conducted using an optical chamber with a paraffin wax slab exposed to high shear flows of 71–234 kg/m $$^2-$$ 2 - s with non-vitiated heated air at 84–199 $$^{\circ }$$ ∘ C. The formation of a lobe structure and leading edge instability responsible for wax atomization is imaged and quantified. The lobe height and receding angle are measured, and a simplified theory is developed to predict the steady-state shape using a sinusoidal profile. A Weber number of the leading edge is defined (We $$_\textrm{LE}$$ LE ) to non-dimensionalize and correlate the experimental data to the theory. A linear correlation is observed with an $$R^2$$ R 2 of 0.94 between the shear correction factor and We $$_\textrm{LE}$$ LE . The overall agreement between theory and measurements is good for the lobe height and width. Measurements of entrainment from the lobe account for $$\approx 20\%$$ ≈ 20 % of the total mass loss. The size of the droplets entrained from the leading edge are recorded and normalized. Droplet size distributions for varying air fluxes and temperature are shown to collapse to the same distribution when normalized using their z-scores.
Source: Experiments in Fluids
Institution: University at Buffalo, State University of New York
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,590
Awards: EXISTING LIQUID PROPULSION SYSTEMS ARE COMPLEX AND SEEM TO HAVE REACHED
THE LIMIT FOR FUEL ENERGY DENSITY. A BREAKTHROUGH THAT SIGNIFICANTLY INCREASES THE ENERGY DENSITY, OR
SPECIFIC IMPULSE, OF THE PROPELLANT WOULD GREATLY REDUCE LAUNCH COSTS, ACCELERATING ACCESS TO SPACE
AND ITS INDUSTRIAL DEVELOPMENT., G534410974, G6569714663
OpenAlex ID: W4414158726