Numerical exploration of heat transfer and friction factor in corrugated dual-pipe heat exchangers using SiO2and CuO nanofluids

•The heat transfer performance of the external corrugated inner tube outperformed the inner corrugated inner tube.•CuO nanofluid demonstrates superior heat transfer performance compared to SiO2and water.•f is increased by 71.39% at 25∘helix angle for inner corrugated tube and 61.23% for outer corrugated tube.•At α = 25∘the heat transfer rates augmented across all studied Rerange.