Enhanced Evaporation of Microscale Droplets With an Infrared LaserSource: Journal of Heat Transfer:;2017:;volume( 139 ):;issue: 001::page 11503Author:Ferraz-Albani, Luis A.
,
Baldelli, Alberto
,
Knapp, Chrissy J.
,
Jäger, Wolfgang
,
Vehring, Reinhard
,
Nobes, David S.
,
Olfert, Jason S.
,
Kostiuk, Larry W.
DOI: 10.1115/1.4034486Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: Enhancement of water droplet evaporation by added infrared radiation was modeled and studied experimentally in a vertical laminar flow channel. Experiments were conducted on droplets with nominal initial diameters of 50 μm in air with relative humidities ranging from 0% to 90% RH. A 2800 nm laser was used with radiant flux densities as high as 4 × 105 W/m2. Droplet size as a function of time was measured by a shadowgraph technique. The model assumed quasi-steady behavior, a low Biot number liquid phase, and constant gas–vapor phase material properties, while the experimental results were required for model validation and calibration. For radiant flux densities less than 104 W/m2, droplet evaporation rates remained essentially constant over their full evaporation, but at rates up to 10% higher than for the no radiation case. At higher radiant flux density, the surface-area change with time became progressively more nonlinear, indicating that the radiation had diminished effects on evaporation as the size of the droplets decreased. The drying time for a 50 μm water droplet was an order of magnitude faster when comparing the 106 W/m2 case to the no radiation case. The model was used to estimate the droplet temperature. Between 104 and 5 × 105 W/m2, the droplet temperature changed from being below to above the environment temperature. Thus, the direction of conduction between the droplet and the environment also changed. The proposed model was able to predict the changing evaporation rates for droplets exposed to radiation for ambient conditions varying from dry air to 90% relative humidity.
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contributor author | Ferraz-Albani, Luis A. | |
contributor author | Baldelli, Alberto | |
contributor author | Knapp, Chrissy J. | |
contributor author | Jäger, Wolfgang | |
contributor author | Vehring, Reinhard | |
contributor author | Nobes, David S. | |
contributor author | Olfert, Jason S. | |
contributor author | Kostiuk, Larry W. | |
date accessioned | 2017-11-25T07:16:40Z | |
date available | 2017-11-25T07:16:40Z | |
date copyright | 2016/20/9 | |
date issued | 2017 | |
identifier issn | 0022-1481 | |
identifier other | ht_139_01_011503.pdf | |
identifier uri | http://138.201.223.254:8080/yetl1/handle/yetl/4234124 | |
description abstract | Enhancement of water droplet evaporation by added infrared radiation was modeled and studied experimentally in a vertical laminar flow channel. Experiments were conducted on droplets with nominal initial diameters of 50 μm in air with relative humidities ranging from 0% to 90% RH. A 2800 nm laser was used with radiant flux densities as high as 4 × 105 W/m2. Droplet size as a function of time was measured by a shadowgraph technique. The model assumed quasi-steady behavior, a low Biot number liquid phase, and constant gas–vapor phase material properties, while the experimental results were required for model validation and calibration. For radiant flux densities less than 104 W/m2, droplet evaporation rates remained essentially constant over their full evaporation, but at rates up to 10% higher than for the no radiation case. At higher radiant flux density, the surface-area change with time became progressively more nonlinear, indicating that the radiation had diminished effects on evaporation as the size of the droplets decreased. The drying time for a 50 μm water droplet was an order of magnitude faster when comparing the 106 W/m2 case to the no radiation case. The model was used to estimate the droplet temperature. Between 104 and 5 × 105 W/m2, the droplet temperature changed from being below to above the environment temperature. Thus, the direction of conduction between the droplet and the environment also changed. The proposed model was able to predict the changing evaporation rates for droplets exposed to radiation for ambient conditions varying from dry air to 90% relative humidity. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Enhanced Evaporation of Microscale Droplets With an Infrared Laser | |
type | Journal Paper | |
journal volume | 139 | |
journal issue | 1 | |
journal title | Journal of Heat Transfer | |
identifier doi | 10.1115/1.4034486 | |
journal fristpage | 11503 | |
journal lastpage | 011503-8 | |
tree | Journal of Heat Transfer:;2017:;volume( 139 ):;issue: 001 | |
contenttype | Fulltext |