Abstract: In this study, the effects of three types of longitudinal vortex generator (LVG) configurations on the flow and heat transfer characteristics in a rectangular channel were investigated and analyzed by field synergy principle. The results show that the temperature of plate fuel assembly can be decreased and the critical heat flux (CHF) of the reactor will be increased. Compared by the performance evaluation parameter, JF factor, the results indicate that “common flow up” combined with ellipse pole configuration can bring about more enhancement of heat transfer at a modest expense of the additional pressure-loss.