Discrete Phase Model Representation of Particulate Matter (PM) for Simulating PM Separation by Hydrodynamic Unit Operations

Abstract

Modeling the separation of dilute particulate matter (PM) has been a topic of interest since the introduction of unit operations for clarification of rainfall-runoff. One consistent yet controversial issue is the representation of PM and PM separation mechanisms for treatment. While Newton's Law and surface overflow rate were utilized, many historical models represented PM as a lumped gravimetric index largely out of economy and lack of particle analysis methods. As a result such models did not provide information about particle fate in or through a unit operation. In this study, PM discrete phase modeling (DPM) and computational fluid dynamics (CFD) are applied to model PM fate as a function of particle size and flow rate in two common types of hydrodynamic separator (HS) units. The study examines the discretization requirements (as a discretization number, DN) and errors for particle size distributions (PSDs) that range from the common heterodisperse to a monodisperse PSD. PSDs are categorized based on granulometric indices. Results focus on ensuring modeling accuracy while examining the role of size dispersivity and overall PM fineness on DN requirements. The fate of common heterodisperse PSDs is accurately predicted for a DN of 16, whereas a single particle size index, commonly the d(50m), is limited to monodisperse PSDs in order to achieve similar accuracy.

Coupled infiltration and filtration behaviours of concrete porous pavement for stormwater management

“…Influent particle size gradation. The particle size loading is a sandy silt and represents a commonly measured in urban drainage (Sansalone et al ., ; Dickenson and Sansalone, )…”

“…A constant particle size gradation of known dry mass of particles was mixed with deionized water in a well-mixed influent tank, as shown in Figure 2. The particle size loading is a sandy silt and represents a commonly measured type in urban drainage (Sansalone et al, 1998;Dickenson and Sansalone, 2009), as illustrated in Figure 3. Influent suspended sediment concentration (SSC) was undertaken with 50 mg/l.…”

“…Both influent and effluent samples were taken every 60 min to test infiltration rate, SSC and turbidity (t)(Kuang et al, 2007b) Influent particle size gradation. The particle size loading is a sandy silt and represents a commonly measured in urban drainage(Sansalone et al, 1998;Dickenson and Sansalone, 2009)…”

Numerical investigation of the process and flow erosion of flushing oil tank with nitrogen

“…Meanwhile, the particle dynamics are treated in a Lagrangian framework according to the particle equation of motion, including the trajectory of particles, the attack angle and velocity perturbation [14]. At last, the erosion rate can be determined by the mass transfer rate of magnetite on the metal surface [15].…”

Computational fluid dynamics design and forecasting of urban drainage unit operation behaviour

“…Similarly, for filtration, granular filters and permeable pavement filter performance have been examined (Keblin et al [7]). While these approaches have specific advantages, development of multiphase computational fluid dynamics (CFD) (Dickenson and Sansalone [8]) offers a general and dynamic tool to predict and analyze coupled hydrodynamics and PM dynamics in BMPs such as the HS units and filters. Studies have applied CFD to treatment of combined sewer overflow (CSO) for storage chambers.…”