Tomographic Measurements of Ejecta Cloud Concentrations in Plume-Surface Interactions using Millimeter Wave Interferometry

Rasmont, Nicolas; Al-Rashdan, Hussein; Elliott, Gregory S.; Rovey, Joshua L.; Roca, Laura Villafañe

doi:10.2514/6.2023-0465

Cited by 3 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The maximum optical absorbance for the calibration range is 3.6, more than double the absorbance of Barlow and Morrisson's experiment and one to two orders of magnitude higher than the rest of the experiments analyzed. Even higher concentration values were measured using the same instrument during plume-surface interaction demonstration experiments [48], reaching up to 5.71 × 10 9 m −2 . This corresponds to an optical absorbance of 50, far above the capability of any optical system.…”

Section: B Comparison With Optical Techniquesmentioning

confidence: 86%

“…This article is an extension of the works presented in [47] and [48]. Focusing on the specific use case of an ongoing plume-surface interaction experiment, they served to demonstrate the potential of mm-Wave interferometry for rapidly varying optically opaque environments.…”

Section: Introductionmentioning

confidence: 91%

“…If restricted to the unambiguous [0 • , 360 • ] angular range, mm-Wave interferometry is capable of measuring particle concentrations one order of magnitude higher than a laser instrument with a 60 dB dynamic range. The proof-of-concept interferometer developed in this study has been demonstrated to measure phase up to 20π radians [48]. Such a capability extends its measurement range by another order of magnitude, while the signal attenuation stays at a manageable level.…”

Section: B Extinction Effectsmentioning

confidence: 97%

“…11 and corresponds to a path-integrated number concentration and particle size. Data points corresponding to the calibration results presented in this work are included, as well as the range of path-integrated concentrations measured with the mm-Wave interferometer in demonstration experiments for plume-surface interactions [48]. Data points are overlaid on a map of optical absorbance A, (11), calculated using the Beer-Lambert Law using an extinction efficiency Q ext of 2 for geometric scattering.…”

Section: B Comparison With Optical Techniquesmentioning

confidence: 99%

See 3 more Smart Citations

Millimeter-Wave Interferometry for Opaque Particle-Laden Flows

Rasmont

Al-Rashdan

Elliott

et al. 2023

IEEE Trans. Microwave Theory Techn.

View full text Add to dashboard Cite

A novel method to measure the concentration of particles in optically opaque particle-laden flows is presented. This method is based on the principle of millimeter wave interferometry, using a fully-integrated frequency modulated continuouswave (FMCW) radar operating between 77 and 81 GHz to measure path-integrated particle concentrations between the radar and a reflector. The instrument is capable of quantitative, high-speed (20 kHz) path-integrated concentration measurements in dispersed multiphase flows with concentrations one to two orders of magnitude higher than those at reach with state-ofthe-art optical methods. The interferometer was demonstrated and calibrated for path-integrated number concentrations up to (4.36 ± 0.24) × 10 8 m −2 using glass microspheres with a mean diameter of 109.2 µm. Two independent measurements of particle size distribution (PSD) were performed using X-ray microtomography and dry sieving. The calibration setup relied on high-resolution particle shadowgraphy applied to individual thin particle streams and used multistreams superposition to reproduce large optical depths in a controlled particle-air mixture. The instrument exhibited excellent linearity and low error during the calibration, with a phase shift-to-number concentration slope of (1.378 ± 0.043) × 10 −7 m 2 , validating the measurement concept and paving the way for practical applications. The leading uncertainties are discussed, providing guidelines for exploiting the measurement concept without necessarily performing a direct calibration.

show abstract

Section: B Comparison With Optical Techniquesmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 91%

Section: B Extinction Effectsmentioning

confidence: 97%

Section: B Comparison With Optical Techniquesmentioning

confidence: 99%

See 2 more Smart Citations