Single-Dye Multispectral PLIF (SDMS-PLIF) For Quantitative Thermographic Visualisation Of Nucleate Boiling
Zengchao Chen (1), Surya Narayan (1), Aleksei S. Lobasov (1), Konstantin S. Pervunin (2), Christos N. Markides (1)
1. Clean Energy Processes (CEP) Laboratory, Department of Chemical Engineering, Imperial College London, Sw7 2az London, United Kingdom
2. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences (IT SB RAS), 630090 Novosibirsk, Russia
DOI:
The boiling of dielectric fluids in miniaturised channels has emerged as one of the most promising solutions to high- density electronics cooling. Although significant breakthroughs have been made, a fundamental understanding of the hydrodynamic and thermal performance in relevant flows is still lacking, which calls for further development of state-of-the-art measurement techniques and their deployment for the provision of high-quality, detailed experimental information. To this end, we conducted an experimental investigation of flow boiling in a miniaturised vertical square channel with a hydraulic diameter of 5 mm, using HFE-7100 as the working fluid. A whole-field thermographic imaging approach referred to as single-dye multispectral planar laser-induced fluorescence (SDMS-PLIF) was developed and applied to measure spatiotemporally-resolved temperature fields. For its implementation, Nile Red, a thermosensitive lipophilic dye, was dissolved in HFE-7100 as a fluorophore. The measurements were taken at selected conditions to achieve a nucleate boiling regime in a laminar flow. Time-lapse temperature maps provided direct evidence for bubble-induced mixing observed as thermal plumes, where a portion of hot fluid is advected above the thermal boundary layer at the heated wall and penetrates the colder bulk phase in the flow core.
