Advancements in laser-based spatiotemporal measurements of flow boiling

Chen, Zengchao; Narayan, Surya; Lobasov, Aleksei S.; Pervunin, Konstantin S.; Falsetti, C.; Bucci, Matteo; Markides, Christos N.

doi:10.1088/1742-6596/2766/1/012153

Advancements in laser-based spatiotemporal measurements of flow boiling

Title

Advancements in laser-based spatiotemporal measurements of flow boiling

Author

Chen, Zengchao (Imperial College London)
Narayan, Surya (Imperial College London)
Lobasov, Aleksei S. (Imperial College London; Russian Academy of Sciences)
Pervunin, Konstantin S. (Russian Academy of Sciences)
Falsetti, C. (TU Delft Flight Performance and Propulsion)
Bucci, Matteo (Massachusetts Institute of Technology)
Markides, Christos N. (Imperial College London; Russian Academy of Sciences)

Date

2024

Abstract

Recent advancements in laser and imaging systems, as well as in computational processing capabilities, have made quantitative optical imaging, which is often combined with laser illumination, highly adaptable, robust and reliable. Laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), offer the possibility of simultaneous spatiotemporally resolved measurements of temperature fields in the liquid phase at boiling conditions. In this paper, we examine the applicability of two-colour PLIF (2cPLIF), where the ratio between individual fluorescent emissions from uniformly dispersed dyes is used to take temperature measurements in the liquid phase in the presence of moving vapour-liquid interfaces typical of boiling flow. The implementation of 2cPLIF necessitates uniformity in the concentration of different dyes across the flow field. However, in the case of a multiphase flow such as boiling, thermophoresis can lead to inhomogeneous dye distributions. To overcome this challenge, a single-dye multispectral planar laser-induced fluorescence (SDMS-PLIF) method has been developed, which employs fluorescent emissions in different spectral bands of the same dye (Nile Red). The spectral characteristics of Nile Red were measured using a spectrometer to identify its temperature-sensitive bands over a wide range of dye concentrations, from 0.3 to 30 mg/L. Following this, we demonstrate the measurement capabilities of SDMS-PLIF thermography as applied to a boiling flow in a miniaturised vertical square channel, gaining insight into the thermohydrodynamic interactions between vapour bubbles and a heated wall.

To reference this document use:

http://resolver.tudelft.nl/uuid:6e6e41a7-eea1-4e74-98bd-bdbcee6721d6

DOI

https://doi.org/10.1088/1742-6596/2766/1/012153

ISSN

1742-6588

Source

Journal of Physics: Conference Series, 2766 (1)

Event

9th European Thermal Sciences Conference, EUROTHERM 2024, 2024-06-10 → 2024-06-13, Bled, Slovenia

Part of collection

Institutional Repository