Sensitivity of the Heat Transfer Coefficient Calculation

Abstract

The purpose of the Liscic/Petrofer probe is to determine the cooling intensity during liquid quenching in laboratory and workshop environments. The surface heat transfer coefficient is calculated by the one-dimensional finite volume method from the smoothed temperature curve, measured at a near-surface point in the probe. Smoothed reference temperature curves for oil and water, based on measurements made by the probe, are used in a series of numerical experiments to investigate the sensitivity of the calculation with respect to various input parameters of the problem, such as: thermal properties of the material, the near-surface thermocouple position, and the diameter of the probe. These results are relevant for other liquid quenchants, at least qualitatively, if not quantitatively. A similar type of analysis is conducted with respect to the variation of numerical simulation parameters in the finite volume method---the choice of space and time steps for problem discretization. When the input curves are sufficiently smooth, the method itself is very reliable.