“…This difference was reproducible and was related to fluid velocity, heat flux, and temperature difference (£s -U). Earlier work (19) showed that the same average linear temperature profile was obtained with couples located along the top and bottom of a tube, as with couples located along the top, bottom, and each side. In this study, couples were positioned on the top and bottom to give an average linear temperature profile, from which the average outside-wall temperature, tw, was determined at the mid-point of each 12-inch measurement section.…”