A tracer-free photographic method for the estimation of the velocity field in a liquid metal pool

Abstract Accurately measuring the velocity field (VF) of liquid metals is essential for optimizing and controlling high-temperature industrial processes, yet remains a challenging task despite the numerous existing velocimetry techniques. In this paper, a methodology for estimating the VF of a liquid metal pool is proposed. The experimental set-up used here to heat the metal sample up to the liquid state and collect data is presented. This set-up primarly intented to perform flash experimetns on liquid metals, allows contactless heating and data measurements by a high speed camera. The proposed methodology for estimating the VF consists then in implementing a Non-Rigid Registration between the different frames of the recorded temperature fields (TFs). This method is applied on TFs resulting from multiple experimental tests conducted on iron samples in the temperature range of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>1</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mn>850</mml:mn> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mn>100</mml:mn> </mml:mrow> </mml:math> K. The consistency of the results is put to test via multiple validation tests. The influence of the main parameters is also evaluated. The results show that the proposed methodology allows a fine experimental quantification of liquid metal VFs with an estimated error of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mtext> </mml:mtext> <mml:mn>8</mml:mn> <mml:mi mathvariant="normal">%</mml:mi> </mml:mrow> </mml:math> and confirm the feasibility of the proposed approach.