An experimental investigation of the interaction between a double-orifice synthetic jet with an approaching turbulent boundary layer developing on the bottom wall of square channel has been carried out. Schlieren visualization and velocity measurement using hotwire anemometry are carried out to characterize the synthetic jet actuators arrangement. Detailed heat transfer measurements are carried out using liquid crystal thermography. Hotwire measurements on the wall surface have been reported to understand the interaction between the approaching boundary layer and synthetic jet. Maximum overall heat transfer enhancement of 55.48% at an actuation voltage of 55V is observed with entropy generation number equal to 0.649. The amplitude modulation is observed to increase the heat transfer enhancement in comparison to that without amplitude modulation.