Investigation of the effect of various corrugated pipe configurations on thermo-hydraulic flow and enhancement of heat transfer performance with the development of different correlations

In this investigation, determinations of thermo-hydraulic flow behaviour, heat transfer enhancement, and overall thermal performance of fluid passing within a corrugated pipe with constant heat flux were carried out using numerical simulation techniques. The numerical calculations were performed with applied computational fluid dynamics methods, and the flow patterns, pressure drops, heat transfer coefficients, friction factors, Nusselt numbers, ratios of the Nusselt number, and the friction factor for corrugated pipe with respect to smooth pipe and thermal performance factors are predicted under different corrugated pipe geometry configurations and ranges of Reynolds Numbers. Three different important geometric parameters for corrugated pipe were changed throughout the numerical calculations, including corrugated ring diameters (of 1, 2 and 3 mm), corrugated ring angles (of 120?degrees, 240 degrees, and 360 degrees) and distance between the corrugated rings (of 5, 10 and 15 mm). The numerical outcomes observations indicate that as the corrugated configurations increased, the pressure drop was considerably greater. The Nusselt number (Nu) values for all CRD configurations were higher than for the smooth pipe by about 32.2, 40.5, and 45.6%, respectively, for a Re of 12021.9. The Nu values for the CRA value parameters were 17.5, 29.3, and 49.6% higher, respectively than for the smooth pipe. For the DBCR configuration, the Nu were about 49.5, 45.7, 40.9% higher, respectively. Moreover, the outcomes reveal that the best range for PEF is about 1.2-1.6. Various correlations equations for the friction factor (f), Nu, and PEF were developed using Minitab and response surface methodology (RSM) and regression analysis. The average errors of these correlation equations were about 13%, 9.75%, and 13.33%, respectively.