Drop size distribution measured by imaging: determination of the measurement volume by the calibration of the point spread function
| Autor: | Nicolas Fdida, Jean-Bernard Blaisot |
|---|---|
| Přispěvatelé: | Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2009 |
| Předmět: |
Diffraction
Point spread function Opacity Analyser 02 engineering and technology 01 natural sciences Control volume [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] 010305 fluids & plasmas law.invention Physics::Fluid Dynamics Optics 020401 chemical engineering law 0103 physical sciences 0204 chemical engineering Instrumentation Engineering (miscellaneous) ComputingMilieux_MISCELLANEOUS Mathematics business.industry Applied Mathematics Drop (liquid) Laser Sizing [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic business [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing |
| Zdroj: | Measurement Science and Technology Measurement Science and Technology, IOP Publishing, 2010, 21 (2), pp.025501. ⟨10.1088/0957-0233/21/2/025501⟩ |
| ISSN: | 1361-6501 0957-0233 |
| DOI: | 10.1088/0957-0233/21/2/025501 |
| Popis: | Measurement of drop size distributions in a spray depends on the definition of the control volume for drop counting. For image-based techniques, this implies the definition of a depth-of-field (DOF) criterion. A sizing procedure based on an imaging model and associated with a calibration procedure is presented. Relations between image parameters and object properties are used to provide a measure of the size of the droplets, whatever the distance from the in-focus plane. A DOF criterion independent of the size of the drops and based on the determination of the width of the point spread function (PSF) is proposed. It allows to extend the measurement volume to defocused droplets and, due to the calibration of the PSF, to clearly define the depth of the measurement volume. Calibrated opaque discs, calibrated pinholes and an optical edge are used for this calibration. A comparison of the technique with a phase Doppler particle analyser and a laser diffraction granulometer is performed on an application to an industrial spray. Good agreement is found between the techniques when particular care is given to the sampling of droplets. The determination of the measurement volume is used to determine the drop concentration in the spray and the maximum drop concentration that imaging can support. |
| Databáze: | OpenAIRE |
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