Implementation of direct curve matching methods for transient matrix heat transfer testing

Abstract

A method is described which permits in the entire practical N tu-range the numerical reduction of transient matrix heat transfer test data resulting from single blow experiments. Two particular cases are analyzed in detail: (1) the idealized case where the upstream fluid temperature follows a step change, and (2) the more realistic case where the upstream fluid temperature follows a decreasing exponential function, which is an acceptable assumption whenever a fast response electrical heater is employed to produce the upstream fluid temperature change. Discrete direct curve matching as formulated in this paper consists of minimizing a suitable distance function defined on discrete sets of data points. In an appendix to the present paper, the implementation of a direct curve matching method is presented for the more general case of an “arbitrary” upstream fluid temperature change.