Enhancing thermo-hydraulic performance in dimpled channels with wavy tape inserts for heat pipe & heat exchanger design with complex energy systems

The present study reports on a novel prototype of a wavy-tape insert designed to enhance heat transfer in pipes. The prototype features a dimpled channel pipe with a wavy-tape positioned centrally within it. The characteristics of flow and heat transmission are studied using computational fluid dynamics simulations. Full-scale simulations assuming turbulent flow regime with Re ranging from 10,000 to 25,000 are studied in the thermal entrance region under constant heat flux boundary conditions. The numerical results were validated against existing experimental data for a similar wavy-tape insert geometry, demonstrating good agreement within a ±3.5% deviation for the Nusselt number. The overall heat transfer enhancement ratio of the wavy-tape insert can reach up to 2.0. This insert induces a swirl flow structure within the pipe, which is observable. On the tape flanks, it has been seen that pairs of vortices are produced, improving the efficiency of pipe heat transfer. The impact of the wavy-tape's amplitude and width on the thermal–hydraulic performance of the pipe is investigated through parametric analyses. Parametric studies reveal that the thermal performance of the channel improves with increasing tape width (W/D) but deteriorates with increasing Reynolds number (Re). Conversely, thermal performance decreases as the amplitude of the tape (A/W) increases. Notably, the Performance Evaluation Criterion (PEC) remains relatively insensitive to variations in tape thickness (t/D). Upon investigating different case studies, the optimized configuration of the channel was suggested. This study demonstrates the potential of the proposed design to enhance heat transfer in pipes and paves the way for developing high-performance heat exchangers for various applications.