Optical droplet vaporization of micron-sized perfluorocarbon droplets and their photoacoustic detection

2011 ◽  
Author(s):  
Eric Strohm ◽  
Min Rui ◽  
Ivan Gorelikov ◽  
Naomi Matsuura ◽  
Michael Kolios
Keyword(s):  
Photoacoustic Detection ◽  
Droplet Vaporization

n-HEPTANE DROPLET VAPORIZATION USING MOLECULAR DYNAMICS

2010 ◽  
Vol 20 (7) ◽  
pp. 581-593 ◽  
Author(s):  
Brad A. Petrilla ◽  
Mario F Trujillo ◽  
Michael Micci
Keyword(s):  
Molecular Dynamics ◽  
Droplet Vaporization

scholarly journals Photoacoustics for listening to Metal Nanoparticles Super-Aggregates

2021 ◽  
Author(s):  
Roberto Li Voti ◽  
Grigore Leahu ◽  
Concita Sibilia ◽  
Roberto Matassa ◽  
Giuseppe Familiari ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Size Distribution ◽  
Packing Density ◽  
Self Assembly ◽  
Détection Signal ◽  
Photoacoustic Detection ◽  
New Strategy ◽  
Aggregate Packing ◽  
Detection Signal

Photoacoustic detection signal has been used to build a new strategy to determine the mesoscale self-assembly of metal nanoparticles in terms of size distribution and aggregate packing density (metal nanoparticles...

The Mystery of Ice Crystal Multiplication in a Laboratory Experiment

2013 ◽  
Vol 71 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Gianni Santachiara ◽  
Franco Belosi ◽  
Franco Prodi
Keyword(s):  
Laboratory Experiment ◽  
Supercooled Liquid ◽  
Ice Crystals ◽  
Formation Processes ◽  
Ice Crystal ◽  
Droplet Vaporization ◽  
Ice Nuclei ◽  
Cold Room ◽  
The Mean ◽  
Ice Multiplication

Abstract This paper addresses the problem of the large discrepancies between ice crystal concentrations in clouds and the number of ice nuclei in nearby clear air reported in published papers. Such discrepancies cannot always be explained, even by taking into account both primary and secondary ice formation processes. A laboratory experiment was performed in a cylindrical column placed in a cold room at atmospheric pressure and temperature in the −12° to −14°C range. Supercooled droplets were nucleated in the column, in the absence of aerosol ice nuclei, by injecting ice crystals generated outside in a small syringe. A rapid increase in the ice crystal concentration was observed in the absence of any known ice multiplication. The ratio between the mean number of ice crystals in the column, after complete droplet vaporization, and the number of ice crystals introduced in the column was about 10:1. The presence of small ice crystals (introduced at the top of the column) in the unstable system (supercooled droplets) appears to trigger the transformation in the whole supercooled liquid cloud. A possible explanation could be that the rapidly evaporating droplets cool sufficiently to determine a homogeneous nucleation.

Photoacoustic detection of microcracks induced in BK7 glass by focused laser pulses

2003 ◽  
Vol 40 (1-2) ◽  
pp. 5-11 ◽  
Author(s):  
M. Navarrete ◽  
M. Villagrán-Muniz ◽  
L. Ponce ◽  
T. Flores
Keyword(s):  
Laser Pulses ◽  
Photoacoustic Detection ◽  
Bk7 Glass

Fuel Droplet Evaporation in a Supercritical Environment

2002 ◽  
Vol 124 (4) ◽  
pp. 762-770 ◽  
Author(s):  
G. S. Zhu ◽  
S. K. Aggarwal
Keyword(s):  
Experimental Data ◽  
Phase Equilibrium ◽  
Ambient Pressure ◽  
Droplet Surface ◽  
Fuel Vapor ◽  
Phase Solubility ◽  
Liquid Density ◽  
Ambient Temperatures ◽  
Droplet Vaporization ◽  
Wide Range

This paper reports a numerical investigation of the transcritical droplet vaporization phenomena. The simulation is based on the time-dependent conservation equations for liquid and gas phases, pressure-dependent variable thermophysical properties, and a detailed treatment of liquid-vapor phase equilibrium at the droplet surface. The numerical solution of the two-phase equations employs an arbitrary Eulerian-Lagrangian, explicit-implicit method with a dynamically adaptive mesh. Three different equations of state (EOS), namely the Redlich-Kwong (RK), the Peng-Robinson (PR), and Soave-Redlich-Kwong (SRK) EOS, are employed to represent phase equilibrium at the droplet surface. In addition, two different methods are used to determine the liquid density. Results indicate that the predictions of RK-EOS are significantly different from those obtained by using the RK-EOS and SRK-EOS. For the phase-equilibrium of n-heptane-nitrogen system, the RK-EOS predicts higher liquid-phase solubility of nitrogen, higher fuel vapor concentration, lower critical-mixing-state temperature, and lower enthalpy of vaporization. As a consequence, it significantly overpredicts droplet vaporization rates, and underpredicts droplet lifetimes compared to those predicted by PR and SRK-EOS. In contrast, predictions using the PR-EOS and SRK-EOS show excellent agreement with each other and with experimental data over a wide range of conditions. A detailed investigation of the transcritical droplet vaporization phenomena indicates that at low to moderate ambient temperatures, the droplet lifetime first increases and then decreases as the ambient pressure is increased. At high ambient temperatures, however, the droplet lifetime decreases monotonically with pressure. This behavior is in accord with the reported experimental data.

Sign in / Sign up

Export Citation Format

Share Document