Method of reconstructing two-dimensional velocity fields on the basis of temperature field values measured with a thermal imaging camera

Abstract

This paper describes a novel numerical reconstruction procedure (NRP) of the velocity field during natural convective heat transfer from a two-sided, isothermal, heated vertical plate based only on the known temperature field obtained, e.g. with a thermal imaging camera. It has been demonstrated that with a knowledge of temperature distributions, the NRP enables the reconstruction of velocity fields by solving the Navier-Stokes equation with an additional momentum source term that replaces the Fourier-Kirchhoff equation. This is because its role is played by the known temperature field, which is the equivalent of its solution.Experimental tests were performed in the air on a symmetrically heated, double-sided, isothermal vertical plate with dimensions of 150×75×2.1 mm. In this test we used a thermal imaging camera with a temperature field detector in the form of a mesh parallel to the gravity acceleration vector, perpendicular to the heating surface and adjacent to the plate in the middle of its width. It was demonstrated that with a temperature field in the form of a results matrix, such reconstruction was possible and that the results obtained were consistent with other experimental results reported elsewhere and with SNC.Along with recreating the velocity field using a standard numerical calculation (SNC), the temperature distributions and velocity fields of the plate under consideration were carried out in parallel and then compared with thermal imaging camera temperature measurements (CTM) and a reconstructed velocity field (NRP).