Numerical analysis of the nanofluid flow characteristics of perforated conical rings in a heat exchanger tube has been investigated under constant wall temperature condition. The pitch ratio of the perforated conical rings is 4 and the number of holes is varied from 0 -typical conical ring- to 10. The flow regime is fully turbulent with the Reynolds number is varied from 5000 to 14,000 and Cu-water nanofluid 0 to 1.5% is selected as the working fluid. The main novelty of this paper is to perform a 3D simulation of this problem because some previous studies using similar geometry were restricted to experimental analysis. The Reynolds averaged Navier Stokes -RANS- equations are solved with the finite volume method using -RNG- K- ∊ model. A significant heat transfer enhancement is obtained by using compound perforated conical rings and nanofluids. The heat transfer enhancement provided by PCR with N = 4 is 278.2% higher than plain tube. The maximum thermal performance of 1.10 is obtained by using Cu-water nanofluid with 1.5% and perforated conical rings with N = 10 at Re = 5000.

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