This research investigates the heat transfer and fluid flow characteristics of a double pipe heat exchanger enhanced with perforated turbulators. The study focuses on the effects of varying Reynolds numbers and geometric configurations, particularly the number of perforations in the inserts, on thermal performance. Using the finite volume method and Ansys Fluent simulations, the heat exchanger was analysed under different conditions, comparing the results with a smooth tube configuration. The findings reveal that the pitch ratio of 2.5 has shown the highest heat transfer capacity followed by pitch ratios of 4.5 and 6.5. Further, irrespective of relative pitch ratio, the ring with no perforations has shown the highest value of average Nusselt number and in the case of perforation, the open area ratio of 0.068 has yielded the best thermal performance.