Assessment Improvement of Heat Performance and Hydraulic Thermal Flow in a Three-Dimensional Tube Equipped With Different Turbulator Corrugated Arrangements

Abstract

Corrugated pipe is used in many engineering applications because of its high performance compared with smooth pipe. This research involved numerical simulations and experimental testing of a circular tube with a modified flow path to improve the heat transfer performance of heat exchangers. The focus was on enhancing mixing and creating vortex flows within the tube to increase heat exchange efficiency. The impact of seven design factors, including ring diameters (RD) and the pitch between ring pitches (RP), on thermal–hydraulic performance was investigated. Water is used as the working fluid and the flow regime ranges from 4000 to 15,000, indicating turbulent flow. A constant heat flux of 25,500 W/m² is applied, and the water enters the system at a temperature of 298 K (25°C). The properties of water are assumed to remain constant throughout the flow with flow conditions, such as a steady state (the flow conditions do not change with time), incompressible flow (the density of the fluid remains constant), and no-slip condition (the fluid velocity at the surface of any solid boundary is zero). Corrugated tubes consistently outperformed smooth tubes in heat transfer due to increased flow mixing and separation. Both increasing the Reynolds number and decreasing the design factors led to the formation of mixing and vortex patterns. In RD configurations, the Nusselt number saw an average improvement of approximately 45.6%, while the friction factor increased between 19% and 57%. RP configurations demonstrated a broader range of Nusselt number enhancements, reaching up to 35%, and friction factor increases ranging from 15% to 42%. Rings can significantly enhance the thermal–hydraulic performance of tubes. However, the best configuration depends on the specific application. The configuration with the highest performance, resulting in a 1.38 increase in performance evaluation factor, was obtained using an RD of 1 mm and an RP of 20 mm. The simulated and experimental data showed excellent agreement, with a maximum discrepancy of less than 11% for both smooth and dimpled tubes.