Search results for "droplet size"
showing 7 items of 7 documents
Observed and Simulated Variability of Droplet Spectral Dispersion in Convective Clouds Over the Amazon
2021
In this study, the variability of the spectral dispersion of droplet size distributions (DSDs) in convective clouds is investigated. Analyses are based on aircraft measurements of growing cumuli near the Amazon basin, and on numerical simulations of an idealized ice‐free cumulus. In cleaner clouds, the relative dispersion ϵ, defined as the ratio of the standard deviation to the mean value of the droplet diameter, is negatively correlated with the ratio of the cloud water content (qc) to the adiabatic liquid water content (qa), while no strong correlation between ϵ and qc/qa is seen in polluted clouds. Bin microphysics numerical simulations suggest that these contrasting behaviors are associ…
Analysis of Dissolved-Gas Atomization: Supercritical CO2 Dissolved in Water
2010
Supercritical dissolved-gas atomization is an atomization process in which carbon dioxide at temperature and pressure above its critical point is used as the atomizing gas. The spray characteristics in terms of droplets size and distribution have been experimentally studied using a laser diffraction method based on a Malvern apparatus. The main parameter that influences the droplets size is the gas-to-liquid mass ratio (GLR); the injection pressure in the range of 7.4-13 MPa has a minor effect. Upon variation of the GLR from 0.5 to 3, the droplet mean diameter changes from about 8.0 to 2.0 μm; very narrow droplet size distributions are also produced. From the point of view of the atomizatio…
Stima della potenza cinetica della precipitazione a partire da osservazioni disdrometriche di distribuzioni dimensionali delle gocce di pioggia
2011
Lo studio del distacco delle particelle di suolo operato dalla pioggia richiede la conoscenza delle caratteristiche erosive della precipitazione. Nella memoria, dopo aver richiamato i presupposti teorici della legge di Ulbrich e le espressioni della potenza cinetica da essa deducibili, viene presentata una verifica di applicabilita della suddetta distribuzione teorica sulla base delle distribuzioni dimensionali delle gocce di pioggia rilevate mediante un disdrometro ottico installato presso la sezione Idraulica del Dipartimento dei Sistemi Agro-Ambientali dell’Universita di Palermo. Viene proposta, infine, una verifica sperimentale dell’equazione di Wischmeier e Smith per il calcolo della p…
M4_Microfluidics_for_CNT
2018
Size and frequency of the droplets produced in T-junction as a function of continuous and disperse phase pressure ratio.
Use of supercritical CO2 and N2 as dissolved gases for the atomization of ethanol and water
2012
Supercritical dissolved gas atomization (SDGA) is an atomization process in which a gas at temperatures and pressures above the critical point is used as the atomizing medium. The concept of SDGA has been applied mainly using CO 2 as atomizing gas in various processes developed for the production of fine particles of pharmaceuticals, polymers, and chemical products and for the atomization of fuels. In this work, SDGA, using ethanol and water as the liquids to be atomized, has been experimentally studied. The spray characteristics, in terms of droplet size and distribution, have been investigated using a laser diffraction analyzer. Ethanol has been chosen due to the large miscibility with CO…
Flavor release from salad dressings: sensory and physicochemical approaches in relation with the structure
2000
The effect of process and formulation on sensory perception and flavor release was investigated on salad dressing models. Oil/vinegar emulsions (φ = 0.5, droplet size > 10 μm) with thickeners and a whey protein concentrate were prepared with different fat droplet sizes and different distributions of fat droplet size. The effect of the amount of emulsifier was also tested. Sensory profile analysis was performed by a trained panel and flavor release quantified by dynamic headspace analysis. When the droplet size is increased, the lemon smell and citrus aroma significantly increase, whereas the egg note, mustard, and butter aroma significantly decrease. The concentrations of alcohols and acids…
Spray droplet characteristics measured using high speed imaging techniques
2016
Presented at Conference International Advances in Pesticide Application (IAPA), Barcelone, ESP (2016-01-13 - 2016-01-15).; International audience; Spray droplet characteristics are important features of an agricultural spray. The objective of this study is to measure the droplet size for different types of hydraulic spray nozzles using a developed backlighted image acquisition system and image processing technique. An in-focus droplet criterion was established to decide whether a droplet is in focus and can be measured in an accurate way. Tests included five different nozzles (Albuz ATR orange and red, TeeJet XR 110 01, XR 110 04 and Al 110 04).