Numerical Investigation of Turbulent Convective Heat Transfer of Distilled Water Flowing in Corrugated Converging Pipes

This study examined the turbulent heat transfer performance, the Poiseuille number, and the performance evaluation criterion (PEC) of distilled water flowing in corrugated converging pipes. It systematically investigated the effects of the amplitude of the corrugation (0.02 ? e/D ? 0.03)and the Reynolds number (0.5 x 10?4 ? Re ? 4.0 x 10?4) on both thermal and flow fields. The governing equations and boundary conditions were numerically solved using the Shear Stress Transport (SST) turbulence model. The results indicated that as the corrugation amplitude increased, the average Nusselt number (Nu), the normalised average Nusselt number NuG, the Poiseuille number fRe, the normalised Poiseuille number fReG, and PEC increased. At Re = 4.0 x 10?4, DR = 1.2, W/D = 0.2 and e/D = (0.02, 0.025 & 0.03), the average Nusselt numbers were 348.48, 360.69 and 368.78, respectively. The corresponding values were 4407.89, 4502.67, and 4571.15, respectively. The NuG values at Re = 1.5 x 10?4 for e/D = 0.02, 0.025 & 0.03 were 1.36, 1.46 and 1.52, respectively. The fReG values at Re = 3.0 x 10?4 for e/D (0.02, 0.025 and 0.03) were 3.16, 3.22 and 3.27, respectively. The corrugated converging pipe enhanced Nu compared with a smooth pipe for all the pipe configurations considered, as revealed by NuG > 1.