Spatially resolved mass transfer coefficient for moderate Reynolds number flows in packed beds: Wall effects. (July 2017)

• Record Type: Journal Article
• Authors: Bale, Shivkumar; Sathe, Mayur; Ayeni, Oladapo; Berrouk, Abdallah S.; Joshi, Jyeshtharaj; Nandakumar, Krishnaswamy
• Is Part Of: International journal of heat and mass transfer. Volume 110(2017)
• Page Start: 406
• Page End: 415
• Publication Date: 2017-07
• Subjects: Mass transfer -- Wall effects -- Packed bed -- Direct numerical simulation (DNS); Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2017.03.052
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Direct Numerical Simulation (DNS) to investigate the effect of confining wall on mass transfer rates. Discrete Element Method - Computational Fluid Dynamics (DEM-CFD) code was used to create geometries. Naphthalene-air system (Sc ∼ 2.52) was considered for all the cases. Probability distribution of particle's Sherwood number all through the packed bed was reported. Abstract: In this paper, Direct Numerical Simulation (DNS) was performed to understand the effects of confining walls on mass transfer through a packed bed for laminar regime ( Re ≤ 100). The X, Y and Z coordinates of the center of the spheres in a randomly packed bed with varying ratios D/d ( D is the diameter of the column and d is the diameter of the particle) were generated using a Discrete Element Method - Computational Fluid Dynamics (DEM-CFD) code. Naphthalene-air system (Sc ∼ 2.52) was considered for all the cases. The grid resolution, method and boundary conditions were validated by comparing the computed (overall) Sherwood number with the published experimental data. Local Sherwood number was computed around each particle for all ratios, D/d, and spatial and probability distributions throughout the packed bed column as a function of D/d are reported. It was observed that for D/d's ≤ 8.6, the effects of wall on particle's Sherwood number was evident, while for D/d's ≥ 10.8, the Sherwood number was predominantly uniform all through the column.