Quantitative imaging of single-shot liquid distributions in sprays using broadband flash x-ray radiography. (December 2016)

• Record Type: Journal Article
• Authors: Halls, B.R.; Roy, S.; Gord, J.R.; Kastengren, A.L.; Meyer, T.R.
• Is Part Of: International journal of multiphase flow. Volume 87(2016)
• Page Start: 241
• Page End: 249
• Publication Date: 2016-12
• Subjects: Flash x-ray -- Synchrotron radiation -- X-ray radiography -- Impinging jet -- Spray imaging -- Liquid distribution; Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2016.09.007
• Languages: English
• ISSNs: 0301-9322

Abstract

Highlights: Quantitative, single-shot 2-D liquid mass distributions measured in atomizing sprays. Attenuation model and calibration procedure accounted for effects of x-ray beam hardening. Flash x-ray radiography compared with time-resolved narrowband synchrotron x-ray source. Resolution, accuracy, precision, and dynamic range evaluated for flash x-ray imaging. Abstract: Flash x-ray radiography is used to capture quantitative, two-dimensional line-of-sight averaged, single-shot liquid distribution measurements in impinging jet sprays. The accuracy of utilizing broadband x-ray radiation from compact flash tube sources is investigated for a range of conditions by comparing the data with radiographic high-speed measurements from a narrowband, high-intensity synchrotron x-ray facility at the Advanced Photon Source (APS) of Argonne National Laboratory. The path length of the liquid jets is varied to evaluate the effects of energy dependent x-ray attenuation, also known as spectral beam hardening. The spatial liquid distributions from flash x-ray and synchrotron-based radiography are compared, along with spectral characteristics using Taylor's hypothesis. The results indicate that quantitative, single-shot imaging of liquid distributions can be achieved using broadband x-ray sources with nanosecond temporal resolution. Practical considerations for optimizing the imaging system performance are discussed, including the coupled effects of x-ray bandwidth, contrast, sensitivity, spatial resolution, temporal resolution, and spectral beam hardening.