Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
EFFECTS OF REYNOLDS AND SCHMIDT NUMBERS ON MASS TRANSFER OF GASEOUS COMPOUNDS FROM QUIESCENT LIQUID SURFACES
Submission Author:
Enilene Lovatte , ES
Co-Authors:
Bruno Furieri, Neyval Reis, jane meri Santos, Melina Peixoto
Presenter: Enilene Lovatte
doi://10.26678/ABCM.ENCIT2016.CIT2016-0257
Abstract
This work aims to study the volatilization of compounds from quiescent liquid surfaces exposed to atmospheric flow using Large Eddy Simulation (LES). Among the gaseous compounds investigated we included an odorant gas of environmental interest, the hydrogen sulphide (H2S). The H2S is commonly dissolved in stabilization ponds of Wastewater Treatment Plants. The mass, momentum and chemical species conservation equations are numerically solved employing a commercial CFD code (Ansys Fluent). We investigated the performance of LES with dynamic subgrid model in the region near the gas-liquid interface. Numerical simulations were performed with Reynolds number based on the friction velocity equal to 150, 640 and 1280 and Schmidt numbers equal to 1, 200 and 580 allowing specific investigation of the effects of these parameters governing the mass transfer phenomenon. The validation of LES was carried out by comparisons with DNS results. The methodology is appropriate in understanding the mass transport and turbulence structures visualization (coherent structures) that directly affect the process. The study demonstrated that LES is suitable for understanding the basic principles of the mass transfer in quiescent surfaces, allowing investigation of the effect of high Reynolds and Schmidt numbers. The influence of Reynolds number is mainly associated with reduced thickness of the diffusive sublayer due to the increase of scalar mixing in the bulk. The thickness of the diffusive sublayer near the free surface greatly decreases in cases where the Schmidt number increases.
Keywords
Mass transfer, LES, Turbulence, Volatilization
