Application of inverse heat conduction calculation method for fast-transient flow boiling heat transfer analysis

A noise robust inverse heat conduction calculation method is applied for the study of fast-transient heat transfer phenomena. This method is useful when the surface of interest is physically inaccessible. A typical finite difference method was modified with a spatial node marching scheme to perform inverse calculations. The Gaussian low-pass frequency filter was adopted to avoid noise induced oscillations during the calculations. Numerical validation of the method, including sensitivity analysis, was performed using a direct one-dimensional heat conduction problem. The developed method predicts the wall temperature and the heat flux with good accuracy, although the inputs to the calculation contain noises. The developed method is demonstrated experimentally using a fast-transient flow boiling test facility. Applying a pulse power on a metallic tube, the resulting temperature response of the tube outer wall was measured with the power transient information simultaneously. The temperature and the heat flux variations on the tube's inner wall were calculated inversely from the measured data. Finally, its potential to fast-transient boiling heat transfer research was emphasized by showing the clearly different transient boiling heat transfer characteristics according to the applied power. (author)