Irreversibility minimization analysis of transient heat transfer for turbulent flow in a circular tube with baffle inserts

In the present work, transient forced-convection heat transfer of circular tubes is investigated experimentally. Semi-circular baffle plates are inserted into the tubes in order to enhance heat transfer characteristics of flow under consideration. The present study reports the effect of several parameters on the thermal characteristics. Mainly, the current study demonstrates the effects of the pitch to tube inlet diameter ratio H/D = 1, 2, 3 and the baffle orientation angle (Β = 45, 90, 180 deg on thermal performance of the present flow under transient conditions. The irreversibility minimization analysis has been taken into consideration while comparing heat transfer enhancement of baffle-inserted tubes. An empirical correlation was developed between the time-averaged irreversibility distribution ratio and irreversibility distribution ratio for steady-state flow conditions for all types of baffle-inserted tubes and empirical correlation constants are tabulated in Table 4 as φt = φ∞ + Be-Re/C . Variation of the irreversibility distribution ratio and time-averaged irreversibility distribution ratio with nine different baffle plate-inserted tubes were analyzed and presented with their comments and graphs. © 2006 by Begell House, Inc.