Analysis of Low-Peclet Heat Transfer During Slug Flow in Tubes With Axial Wall Conduction

An exact solution is presented for the temperature distribution during slug flow inside an infinitely long tube with a finite heated length. The solution takes into consideration axial conduction in the fluid and tube wall, which are characterized by Peclet number and a wall conduction parameter, respectively. Results of bulk and wall temperatures, convective heat flux and Nusselt number are presented for low and high Peclet numbers using a range of values for the wall conduction parameter. It is concluded that wall conduction can have substantial effects on the heat transfer characteristics in the areas surrounding the beginning and end of direct heating. These effects can be much more pronounced than the effects of fluid conduction.