Publikationsdatum:
2015-01-09
Beschreibung:
Photochemical reactors tend to exhibit turbulent flow even with low Reynolds numbers. The k-ϵ model is not always appropriate in this situation. An annular photoreactor was designed with tangential inlet and outlet tubes to investigate this. The fluid flow was characterized by residence time distribution (RTD) experiments, which were reproduced by computational fluid dynamics considering four relevant turbulence models: the k-ϵ , the k-ω , the shear stress transport, and the Reynolds stress models. Inlet effects induced helical flow throughout the reactor, switching to plug flow depending on the flow rate and the turbulence model. The k-ω model properly deals with viscous effects and reproduces the experimental RTD curves with correlation coefficients greater than 0.9566, against 0.8705 from the k-ϵ model. The k-ϵ turbulence model not always accurately predicts confined flows, the main category of a chemical engineer's interest. The presented annular photoreactor is better characterized by the k-ω model due to its formulation of low- Re effects. Advances in computational fluid dynamics codes allow the use of the Reynolds stress model without loss of computational performance.
Print ISSN:
0930-7516
Digitale ISSN:
1521-4125
Thema:
Chemie und Pharmazie
,
Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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