A turbulent mass diffusivity model for analyzing the mixing characteristics in an impinging stream-rotating packed bed

doi:10.1016/j.cjche.2024.06.003

Abstract

Abstract: In this study, the fluid flow and mixing process in an impinging stream-rotating packed bed (IS-RPB) is simulated by using a new three-dimensional computational fluid dynamics model. Specifically, the gas-liquid flow is simulated by the Euler-Euler model, the hydrodynamics of the reactor is predicted by the RNG k-ε method, and the high-gravity environment is simulated by the sliding mesh model. The turbulent mass transfer process is characterized by the concentration variance $\overline{c^2}$ and its dissipation rate ε formulations, and therefore the turbulent mass diffusivity can be directly obtained. The simulated segregation index X_s is in agreement with our previous experimental results. The simulated results reveal that the fringe effect of IS can be offset by the end effect at the inner radius of RPB, so the investigation of the coupling mechanism between IS and RPB is critical to intensify the mixing process in IS-RPB.

Key words: Impinging stream-rotating packed bed, Turbulent mass diffusivity model, Computational fluid dynamics, Mixing performance, Segregation index

摘要： In this study, the fluid flow and mixing process in an impinging stream-rotating packed bed (IS-RPB) is simulated by using a new three-dimensional computational fluid dynamics model. Specifically, the gas-liquid flow is simulated by the Euler-Euler model, the hydrodynamics of the reactor is predicted by the RNG k-ε method, and the high-gravity environment is simulated by the sliding mesh model. The turbulent mass transfer process is characterized by the concentration variance $\overline{c^2}$ and its dissipation rate ε formulations, and therefore the turbulent mass diffusivity can be directly obtained. The simulated segregation index X_s is in agreement with our previous experimental results. The simulated results reveal that the fringe effect of IS can be offset by the end effect at the inner radius of RPB, so the investigation of the coupling mechanism between IS and RPB is critical to intensify the mixing process in IS-RPB.

关键词: Impinging stream-rotating packed bed, Turbulent mass diffusivity model, Computational fluid dynamics, Mixing performance, Segregation index

Chao Zhang, Youzhi Liu, Weizhou Jiao, Guisheng Qi, Zhiguo Yuan, Qiaoling Zhang, Hongyan Shen. A turbulent mass diffusivity model for analyzing the mixing characteristics in an impinging stream-rotating packed bed[J]. Chinese Journal of Chemical Engineering, 2024, 74(10): 133-143.

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