CFD modeling of mass transfer in annular reactors

Evaluation of model parameters for simulating TiO2 coated UV reactors

“…Since both turbulence models predicted accurately the mass transfer coefficient of the experimental runs under turbulent flow regime, the use of any of them in the integrated CFD simulation tool is supported. In a separate study, further research has been performed utilizing other turbulence models, reactor configurations and geometries, as well as a wider range of flow rates, for obtaining more comprehensive conclusions on the performance of turbulence models for predicting liquid-wall mass transfer (Duran et al 2009b). …”

Computer Simulations of Photocatalytic Reactors

“…In the above-mentioned equations, ρ is density, U is velocity, P is pressure, τ is viscous stress tensor, µ is molecular viscosity, I is unit tensor, m i is the mass fraction of species i, N is the total number of species, and D m is the molecular diffusivity of species i in the mixture [47]. This model has been successfully applied in the CFD simulations of photocatalytic reactors [43,45,46,49,50,53,[64][65][66][67][68]. This model is preferred for gas-phase photocatalytic reactions.…”

“…The specification of the apparent stress gradient (ρUU) is related to the adapted turbulence model [33]. Four hydrodynamic models are most often considered for modeling photoreactors: (a) standard k-ε model (S k-ε) [36,38,45,69,70], (b) the realizable k-ε model (R k-ε) [45,69], (c) the Reynolds stress model (RSM) [45,69], and (d) the low Reynolds number k-ε model (AKN-developed by Abe, Kondoh, and Nagano [21,45,71]). Duran et al performed the CFD for a single-phase flow mass transfer prediction in annular reactors using different hydrodynamic models.…”

“…In general, the CFD method is widely used in the development of catalytic reactors and analysis of the systems involving fluid flows and heat transfer to understand the interactions of the catalyst with the surrounding reactive flow field in catalytic reactors (gas-solid, liquid-solid, and gas-liquid-solid) [39,40]. In the case of photocatalytic reactors, the CFD-aided modeling procedure also introduces the simulation of fluid flows (single-and multi-phase) and solves the RTE [32,37,[41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. In the case of slurry photoreactor systems, there is the concept of local volumetric rate of energy absorption (LVREA), defined as the energy required by photons absorbed per time and volume inside the photoreactor.…”

Mathematical modeling and design of layer crystallization in a concentric annulus with and without recirculation

“…Another method is to estimate mass transfer effects of building suitable numerical models that allow the prediction of the concentration fields inside the crystallizer. Melt layer crystallization of NaCl–H 2 O solution, which can be stationary or agitated around the wall of an internally cooled cylindrical tube, has been simulated by Guardani et al Duran et al carried out computational fluid dynamics simulations to predict mass transfer with different hydrodynamic models in annular reactors, with a constant concentration assumed at the solid–liquid surface. These models do not predict the effects of convective heat transfer and solid‐layer growth on the concentration distribution in the annulus.…”