• Energy Research

Slurry transportation is an essential process in numerous industrial applications, widely studied for its efficiency in material conveyance. Despite substantial research, the impact of pipe wall roughness on critical metrics such as pressure drop, specific energy consumption (SEC), and the Nusselt number remains relatively underexplored. This study provides a detailed analysis using a three-dimensional computational model of a slurry pipeline, with a 0.0549 m diameter and 3.8 m length. The model employs an Eulerian multiphase approach coupled with the RNG k-ε turbulence model, assessing slurry concentrations Cw = 40–60% (by weight). Simulations were conducted at flow velocities Vm = 1–5 m/s, with pipe roughness (Rh) ranging between 10 and 50 µm. Computational findings indicate that both pressure drop and SEC increase proportionally with roughness height, Vm, and Cw. Interestingly, the Nusselt number appears unaffected by roughness height, although it rises corresponds to Vm, and Cw. These insights offer a deeper understanding of slurry pipeline dynamics, informing strategies to enhance operational efficiency and performance across various industrial contexts.

Abstract The use of flexible plates or “flags” as vortex generators inside a channel was successfully demonstrated as an alternative heat transfer enhancement technique. This paper aims to present a brief review of flag vortex generators for thermal enhancement. Although flag dynamics is widely reported, the review reveals that this heat transfer technique is not widely explored, specifically on the heat transfer performance of flags. Extensive and intensive experimental results are lacking to validate numerical and theoretical predictions. This paper further provides a non-exhaustive list of existing gaps, challenges, and potential research areas in using flags as vortex generators for thermal enhancement, which aims to guide future research directions in this thermal-fluid-structure problem. There is a need to conduct further investigations on this technique to fully establish its thermal characteristics.