Determination Of Heat Transfer Coefficient For Array Of Free Surface Water Jets

The article presents an inverse method for the reconstruction of the spatial distribution of the heat transfer coefficient (HTC) for impinging jets. Single jet influence the heat exchange on limited range, thus the HTC is reconstructed for an array of jets. In this article, there is a discussion regarding an influence of the geometrical parameters and Reynolds number on the spatial distribution of HTC. An inverse method used for HTC retrieval assumes the functional form of temperature and heat flux at the solid surface impinged by the jet. Later, the functional is parameterized and the definition of the convective boundary condition is used to force the temporal invariability of HTC. The parameters of the function are determined from the least squares fit of the temperatures obtained from the inverse model and measured ones. Application of the Levenberg-Marquardt algorithm for solving least squares problem together with a formulation of the inverse problem decreases the influence of the ill-posedness of the inverse problem and thus improves the quality of the results.