Three dimensional numerical simulation and field synergy principle analysis were conducted with simplified periodic models for shell and tube heat exchangers with helical baffles at three helix angles(30?

40癮nd 50?)

and commercial codes of GAMBIT 2.3 and FLUENT 6.3 were adopted in the simulation.It is found that Nusselt number from the model with 40? angle is the largest and the predicted average field synergy intersection angle is the smallest

which is consistent with the field synergy principle.The distribution characteristics of field synergy angles reveal that the distribution is quite uniform through whole shell side of the exchangers.The investigation on local heat transfer characteristics in different regions on the shell side shows that the heat transfer rate in the central region of the heat exchanger increases with the increase of Reynolds number.