This research applied a wind tunnel system and a loudspeaker system to investigate the only axial turbulence intensity effect on heat transfer enhancement in duct flows. The loudspeaker was attached to the exit plane of wind tunnel to generate an acoustic wave inside the wind tunnel system. Nearly constant axial velocity perturbations in the test section of wind tunnel were obtained by carefully adjusting the frequency of the generated acoustic wave. The study included the temperature measurements by thermocouples along a heated wall to obtain the Nusselt numbers and thermal boundary layers under different axial turbulence intensities. Also, the near-wall velocity fields were measured by an LDV system to check the applicability of the developed system and to characterize velocity boundary layer. The results suggest that the axial turbulence intensity plays a negligible role in heat transfer enhancement.