Three-Dimensional CFD Modeling for Optimization of Invert Trap Configuration to Be Used in Sewer Solids Management

Abstract

Flow field prediction and optimization of invert trap configuration have been carried out by using three-dimensional computational fluid dynamics (CFD) modeling with the help of FLUENT software using renormalization group (RNG) k-e along with the discrete phase model (DPM). A hexagonal=tetrahedral shape and map-type nonuniform grid were chosen to discretize the entire computational domain, and a control volume finite difference method was used to solve the governing equations. In the present study, five different invert trap configurations (rectangular with and without lid on both sides, trapezoidal, trapezoidal with rectangular base, and rectangular with trapezoidal base with lid on both sides) have been simulated for the flow of three different inert sediment types (sand, styrocell, and plastic beads) at six flow rates (0.35, 0.70, 1.05, 1.35, 4.55, and 9.95 Lps) for each trap. The discharges selected in the present study cover the entire range of discharge expected in channels during dry weather flow and monsoon. The simulation results are capable of showing particle trajectories and the effect of flow rate and trap geometry on the flow patterns developed within the trap. Based on 3-D CFD modeling and experimental measurements, it has been concluded that the invert trap having a rectangular shape with trapezoidal base with lids on both sides is the most efficient trap configuration with highest sediment retention ratio.

Numerical Simulation of Imported Sediment in a Stilling Basin

“…In this study, we used the RNG turbulent flow model and the DPM discrete phase of FLUENT 16.0 software for numerical calculations. VOF was used for free interface tracking (Thinglas and Kaushal, 2008). The continuity equation, momentum equation and K, and the εequation of the RNG turbulent flow model can be expressed as follows:…”

Control of solid tobacco emissions in industrial fact ories applying CDF tools

“…Although the original problem is a three-dimensional tunnel, as other cases studied before by Thinglas et al [7], the modelling process can be simplified using some feasible arguments. For instance, based on the analysis of the dominant physical sediment transport phenomenon occurred in the axial direction, it is possible to conduct the evaluation of proposed options in qualitatively by a two-dimensional modelling covering the longitudinal geometry of the tunnel, about 55 m long.…”