Study of the droplet size effect coupled with the laser light scattering in sprays for two-color LIF thermometry measurements

Labergue, Alexandre; Delconte, Alain; Castanet, Guillaume; Lemoine, Fabrice

doi:10.1007/s00348-011-1242-8

Cited by 29 publications

(64 citation statements)

References 19 publications

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“…Moreover, g32(D) is different from g12(D) and therefore the ratio Rf32 has a different sensitivity on the droplet size compared to Rf12. As mentioned in Labergue et al, [23], an empirical relationship between both functions g12(D) and g32(D) can be determined experimentally by measuring the corresponding normalized fluorescence ratios for several droplet diameters under isothermal conditions. As a result, a monotonous evolution can be found, which can be easily interpolated by a second order polynomial:…”

Section: Principles Of the Three-color Lif Thermometrymentioning

confidence: 99%

Combined three-color LIF-PDA measurements and infrared thermography applied to the study of the spray impingement on a heated surface above the Leidenfrost regime

Labergue

Pena-Carillo

Gradeck

et al. 2017

International Journal of Heat and Mass Transfer

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This experimental study deals with the impingement of sprays on a heated wall in close to semiindustrial conditions. Therefore, an experimental setup was specifically designed: high liquid mass flux (up to 8 kg/m²/s), large droplets (up to 300 µm) and high surface temperature widely above the Leidenfrost point (up to 800°C). The surface to be cooled is a 175 mm diameter nickel disk with 5 mm thickness heated by electromagnetic induction. The spraying devices consist in full cone sprays. Several studies, performed under these particular conditions, has allowed characterizing the heat flux removed by the spray by using techniques based on thermocouples or infrared thermography (IRT). However, to investigate more finely the heat transfer mechanism, it is necessary to measure the droplet temperature but, to date, no measurement for sprays are available in the literature. Therefore, the objective of the present work is to demonstrate the ability of the three-color Laser Induced Fluorescence (3cLIF) to meet this challenge. The combination of the 3cLIF with a Phase Doppler system allows also determining the droplet temperature per size class before and after impact. By adding the IRT measurements combined to an inverse heat conduction model, an energy balance is done in order to estimate the evaporated liquid mass. The influence of the normal Weber number on the liquid vaporization is investigated by using three sprays (Normal Weber numbers up to about 1500). Thereby, main results show that the droplets temperature after impact increases with the incident Weber number before to reach a plateau, attributed to the apparition of the splashing regime. The analysis of the energy balance shows that the mass of evaporated liquid decreases with the incident Weber number and the droplet heating. These first results are in well agreement with previous works conducted with single calibrated droplets, validating as the same time the use of combined 3cLIF-PDA measurements in the case of sprays.

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Section: Principles Of the Three-color Lif Thermometrymentioning

confidence: 99%

Combined three-color LIF-PDA measurements and infrared thermography applied to the study of the spray impingement on a heated surface above the Leidenfrost regime

Labergue

Pena-Carillo

Gradeck

et al. 2017

International Journal of Heat and Mass Transfer

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“…This was identified as a potential source of error in addition to the afore-mentioned spectral effect of the droplet size (Labergue et al 2012a). The problem can be partially overcome by using detection optics with a very small depth of field like long distance microscopes (Labergue et al 2012a, b).…”

Section: Two-color Single-dye Laser-induced Fluorescence Methodsmentioning

confidence: 99%

“…Temperature measurements in sprays: Several studies have more specifically addressed the implementation of the 2cLIF technique in sprays (Bruchhausen et al 2006;Depredurand et al 2011;Labergue et al 2010Labergue et al , 2012aWolff et al 2007). These studies describe how the 2cLIF technique, initially used and validated in the case of single calibrated droplets, should be modified for reliable measurements in sprays.…”

Section: Two-color Single-dye Laser-induced Fluorescence Methodsmentioning

confidence: 99%

Temperature and chemical composition of droplets by optical measurement techniques: a state-of-the-art review

2013

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“…In opposition to point-wise measurements, temperature measurement techniques based laser sheet illumination are very attractive as they may provide spatially resolved temperature maps. The two-color LIF ratio method has been extensively used over the past years for liquid-and gas thermometry [6][7][8][9][10][11][12][13][14][15][16][17][18]. In order to apply it, one or more dyes are judiciously selected, each producing a temperature sensitive spectral shift in their emitted LIF signals when excited at an appropriate wavelength.…”

Section: Introductionmentioning

confidence: 99%

“…In order to apply it, one or more dyes are judiciously selected, each producing a temperature sensitive spectral shift in their emitted LIF signals when excited at an appropriate wavelength. The two-color ratio approach with a single dye is usually preferred as it eliminates issues related to changes in dye concentration, laser intensity fluctuations, light extinction etc [10][11][12][13][14][15][16][17][18]. Lemoine and associates pioneered this method for thermometry in droplet streams and sprays [10][11][12][13]17,18].…”

Section: Introductionmentioning

confidence: 99%

Thermometry in aqueous solutions and sprays using two-color LIF and structured illumination

Mishra¹,

Nada²,

Polster³

et al. 2016

Opt. Express

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In imaging, the detection of light originating from multiple scattering, indirect reflections and surrounding backgrounds are known to produce errors especially in intensity-ratio based measurements. SLIPI (Structured Laser Illumination Planar Imaging) is an imaging technique that significantly reduces the impact of such issues. In this study, SLIPI is combined with the two-color LIF (Laser Induced Fluorescence) ratio thermometry approach for measuring water temperature in both a cuvette and a hollow-cone spray. By removing the unwanted background interferences using SLIPI, we observe both significant improvements in terms of temperature sensitivity as well as more pronounced temperature gradients within the spray.

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Study of the droplet size effect coupled with the laser light scattering in sprays for two-color LIF thermometry measurements

Cited by 29 publications

References 19 publications

Combined three-color LIF-PDA measurements and infrared thermography applied to the study of the spray impingement on a heated surface above the Leidenfrost regime

Combined three-color LIF-PDA measurements and infrared thermography applied to the study of the spray impingement on a heated surface above the Leidenfrost regime

Temperature and chemical composition of droplets by optical measurement techniques: a state-of-the-art review

Thermometry in aqueous solutions and sprays using two-color LIF and structured illumination

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