Impact of the characteristics of the flow regimes and dynamics of coarse particles fly ash in circular transportation based on CFD-DEM

Yanuar; Raja Fatah Satrio Abimanyu; Gunawan; Sri Poernomo Sari; Chakra  Merdeka

doi:10.71452/yd51zd47

Authors

Yanuar University of Indonesia Author
Raja Fatah Satrio Abimanyu University of Indonesia Author
Gunawan University of Indonesia Author
Sri Poernomo Sari University of Gundarma Author
Chakra Merdeka University of Indonesia Author

DOI:

https://doi.org/10.71452/yd51zd47

Keywords:

fly ash, rheology models, GCI, Erotion, CFD-DEM

Abstract

Fly ash are the primary residues generated from coal combustion, and they represent a serious environmental concern due to their volume and handling complexity. One potential mitigation strategy involves transporting these materials in the form of slurry through pipelines; however, achieving efficient flow remains a significant challenge due to the high concentration of solid particles. This study investigates the energy demands of fly ash slurry flow within circular pipelines using a combined approach of experimental observation and Computational Fluid Dynamics (CFD) simulation. Slurry concentrations of 30%, 40%, and 50% by weight were evaluated. Key flow parameters analyzed include shear stress, shear rate, Reynolds number, and friction factor. The Turbulent Kinetic Energy (TKE) [Figure (c)] shows a clear escalation in kinetic energy with increasing concentration. FA 50% attains the highest kinetic energy (0.0863673), almost twice that of FA 40% (0.0561258) and quadruple that of FA 30% (0.0185431). The CFD simulation results were validated against experimental data, showing a margin of error 6.212%, 4.163%, 5.032[1]% for 30%, 40%, 50% fly ash, and 5.51460%, 8.79267%, 2.72044% for 30%, 40%, 50% bottom ash, respectively, supported by a good Grid Convergence Index of 0.017432% which indicates strong agreement. These findings offer a technical basis for developing energy efficient slurry transport systems and provide further insight into the non-Newtonian behavior characteristic of high solids flow regimes.

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