Optimal Experiment Design for the Identification of the Interfacial Heat Transfer Coefficient in Sand Casting

Abstract

The interfacial heat transfer coefficient (IHTC) is one of the main input parameters required by casting simulation software. It plays an important role in the accurate modeling of the solidification process. However, its value is not easily identifiable by means of experimental methods requiring temperature measurements during the solidification process itself. For these reasons, an optimal experiment design was performed in this study to determine the optimal position for the temperature measurement and the optimal thickness of the rectangular cast iron part. This parameter was identified using an inverse technique. In particular, two different algorithms were used: Levenberg Marquard (LM) and Monte Carlo (MC). A numerical model of the solidification process was associated with the optimization algorithm. The temperature was measured at different positions from the mould/metal interface at d = 0 mm (mould/metal interface), 30 mm, 60 mm and 90 mm. the thicknesses of the cast part were: L1 = 40 mm, 60 mm and 80 mm. A comparative study on the IHTC identification was then carried out by varying the initial value of the IHTC between 500 Wm−2K−1 and 1050 Wm−2K−1. Results showed that the MC algorithm used for estimating the IHTC gives the best results, and the optimal position was at d = 30 mm, the position closest to the mould/metal interface, for the lowest thickness L1 = 40 mm.