Two-dimensional flow visualization and velocity measurement in natural convection near indoor heated surfaces using a thermal image velocimetry method

Wu, Q., Zhu, C.-a., Liu, L., Liu, J. and Luo, Z. ORCID: https://orcid.org/0000-0002-2082-3958 (2019) Two-dimensional flow visualization and velocity measurement in natural convection near indoor heated surfaces using a thermal image velocimetry method. Applied Thermal Engineering, 146. pp. 556-568. ISSN 1359-4311 doi: 10.1016/j.applthermaleng.2018.10.023

Abstract/Summary

Indoor velocity measurement techniques are categorized into point-wise and global-wise measurement techniques. Currently, measurements are either intrusive or restricted to the measurement area. This study presents a thermal image velocimetry (TIV)-based flow measurement method that is suitable for visualizing indoor two-dimensional velocity fields near indoor heated surfaces. The proposed technique uses only an infrared camera for mapping the surface temperature fluctuations. Image processing steps that are used to recover the velocity distribution include the decomposition of the video files into individual frames, the application of filtering to remove background noise, cross-calculation to estimate the velocity, and a final velocity correction based on the continuity equation. To investigate the feasibility of this method, natural convection was studied close to a heated vertical surface in a rectangular cavity. Thermal image velocimetry and particle image velocimetry (PIV) were used to visualize the flow field above a heating unit. The results indicate that the airflow field can be visualized by TIV, and the results measured by TIV are shown to be similar to those for the surface of 6 mm away from the heated surface measured by PIV. A linear correlation is established between TIV and PIV.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/79752
Item Type	Article
Refereed	No
Divisions	Science > School of the Built Environment > Urban Living group Science > School of the Built Environment > Energy and Environmental Engineering group
Publisher	Elsevier
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