Another method to calculate the temperature difference proposed by Utamura should be applied if physical properties are
not constant [8]. From the method, the temperature difference is defined without the assumption of constant specific heat. Therefore,the generalized temperature difference, DTGMTD, can be an accurate index, irrespective of how the physical properties change.For the cases presented in Tables 2 and 3, DTLMTD and DTGMTD were compared. The maximum difference was less than 0.003 K for case number 6 of Table 3 (0.52%). The difference is sufficiently small; it is confirmed that DTLMTD has sufficient accuracy under the small temperature difference condition.From Q and DTLMTD, the heat transfer coefficient, h, is calculated