High frequency temperature fluctuation measurements by Rayleigh scattering and constant-voltage cold-wire techniques

Bertrand Mercier, Emmanuel Jondeau, Thomas Castelain, Yuta Ozawa, Christophe Bailly, Geneviève Comte-Bellot

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Abstract: The thermal inertia of sensors drastically limits the measurement of the temperature fluctuations in the high-frequency range. This issue is often addressed using cold wire techniques with dedicated corrections. In this study, three methods are employed to compensate high-frequency attenuation, and the correction of the end losses, are evaluated for four wires with different aspect ratios and diameters. The fidelity of the corrected measurements is assessed by comparing the spectra of temperature fluctuations obtained with the cold wires operating in a constant voltage circuit, to those derived from optical measurements. The latter method is based on Rayleigh scattering and is in principle not affected by thermal inertia as it relies on molecular light scattering. Two flows presenting high levels of temperature fluctuations are considered. Namely, the wake of a heated cylinder, and a mixing layer between two jets in co-flow and at different temperatures. These two configurations allow exploring cold wire performances at high frequency, and show that precise measurements can be performed up to 10 kHz with a wire 1μm in diameter. Graphic abstract: [Figure not available: see fulltext.].

Original languageEnglish
Article number110
JournalExperiments in Fluids
Volume60
Issue number7
DOIs
Publication statusPublished - 2019 Jul 1

ASJC Scopus subject areas

  • Computational Mechanics
  • Mechanics of Materials
  • Physics and Astronomy(all)
  • Fluid Flow and Transfer Processes

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