They address physical, chemical, and biological processes in water, wastewater, and storm water treatment; the fundamentals of computational fluid dynamics, including turbulence-resolving methodologies and turbulence modeling
, preprocessing, postprocessing, and verification and validation; and water, wastewater, and stormwater treatment technologies and computational fluid dynamics application case studies, discussing aeration, sedimentation, ozone disinfection, pumping intakes, flow distribution to multiple treatment trains, aerated grit tank improvements, optimization of residence time distribution in small water treatment systems, activated sludge tanks, waste stabilization ponds, algae raceway ponds, UV disinfection, geysering, and stormwater collection, filtration, and separation.
Thus it is important to define two equation sets related to the focus of this article: firstly the Navier-Stokes mass, momentum, and energy conservation equations and secondly introducing the problem of turbulence modeling
. Once these models are defined, they are solved by the finite volume method (FVM) used in ANSYS FLUENT.
The version 2016 of the commercial software GT-Power includes one of the most recent approaches for the turbulence modeling
. The procedure is based on the work of Fogla et al.
Almost all the CFD research on this topic reported in the available literature are based on turbulence modeling
approach of RANS.
The applicability of the presented approaches to turbulence modeling
for such Rayleigh numbers can be estimated in the experiments of COPO and BALI, which are presented below.
Choudhury, Introduction to the Renormalization Group Method and Turbulence Modeling
, Fluent Inc., New York, NY, USA, Technical Memorandum TM-107, 1983.
Luo, "Comparative assessment of SAS and DES turbulence modeling
for massively separated flows," Acta Mechanica Sinica, vol.
Wilcox, Turbulence Modeling
for CFD, DCW Industries, Inc, La Canada, Calif, USA, 1993.
The k-m model is used for turbulence modeling
in a range of Reynolds number varying from 500 to 5000.
. For GF investigation at high Reynolds number k-[epsilon] RNG model is chosen as verified by turbulence model dependency studies by Krishnaswamy et al.