Methodology for the application of velocimetry by molecular tagging of hypersonic flows

Vialta, Leda  Marise; Matos, Patrícia Ferraz de; Barreta, Luiz Gilberto; Carinhana, Dermeval

doi:10.1016/j.flowmeasinst.2022.102265

Cited by 5 publications

(1 citation statement)

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“…Thus, PTV generally requires a high frame rate and low particle density [12]. Scharnowski and Kähler [13] reviewed several PTV techniques, including those based on the schlieren method [14,15] and molecular tags [16]. Magnetic resonance velocimetry without particles has also been developed to analyze blood flow in animals and the human body [17], as well as to measure the 3D flow in the internal cooling channels of gas turbine blades [18] and predict residual materials in tanks after drainage [19].…”

Section: Introductionmentioning

confidence: 99%

Analytic Approximation of High-Fidelity Solar Radiation Pressure

Yoshimura

Matsushita

Takahashi

et al. 2023

Journal of Guidance, Control, and Dynamics

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This paper describes the use of a high-speed streaming camera combined with in-house image processing for real-time particle tracking velocimetry (PTV) above 1 kHz. The proposed system is evaluated by measuring the diameter and velocity of multiple free-falling droplets in a simultaneous manner. Two existing particle tracking methods are examined: median flow (MF) and fourframe best estimate (4BE). Area-limiting processing is newly added to MF and 4BE to reduce the region of interest (ROI) in which particles are detected in the next image, resulting in area-limiting MF (AMF) and area-limiting 4BE (A4BE). Except for MF, the rest three methods of AMF, 4BE, and A4BE are capable of 1-kHz real-time PTV for 1246 pixel × 600 pixel images, with 4BE and A4BE achieving even at 10 kHz for 1246 pixel × 100 pixel images. The processing times for the tracking and image preparation are measured, and the bottleneck is found to be the image acquisition and preparation, rather than the tracking. AMF achieves faster processing times than MF in all conditions, showing the effectiveness of the limited ROI, while 4BE and A4BE exhibit comparable performance. The measurement error is confirmed to be approximately 1% for the droplet velocity and diameter, demonstrating the high accuracy of the first in-situ real-time PTV exceeding 1 kHz.

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