Effects of turbulent Schmidt number on CFD simulation of $$45^\circ $$ inclined negatively buoyant jets

Tahmooresi, Sina; Ahmadyar, Davoud

doi:10.1007/s10652-020-09762-6

Cited by 14 publications

(6 citation statements)

References 44 publications

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“…Several turbulence models have been developed to compute these two terms. The present paper employs the realizable 𝑘 − 𝜀 model of Shih et al (1995), which has been used and validated in several studies in the context of dense jets (Kheirkhah Gildeh et al 2015;Ardalan and Vafaei 2019;Tahmooresi and Ahmadyar 2021). The formulation of the realizable 𝑘 − 𝜀 turbulence model is given by:…”

Section: Turbulence Modelingmentioning

confidence: 99%

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: A Numerical Study

Ramezani

Abessi

Firoozjaee

2021

Preprint

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Employing inclined dense jets is a common way for the disposal of brine effluent from coastal desalination plants. This paper numerically analyzes the mixing and geometrical properties of 30° and 45° inclined dense jets when they discharge close to the bed. For this purpose, two series of numerical simulations were developed. First, the nozzle acts as a free jet when it is placed far enough from the lower boundary. Meanwhile, in the second series, the distance between the nozzle tip and seabed is substantially reduced. Consequently, by comparing these two series, the effect of proximity to bed on the behavior of dense jets is investigated. The governing equations are solved by modifying a solver within the CFD package of OpenFOAM. The numerical results are presented in comparative figures and compared to the previous works. Comparisons indicated that the numerical model predicts the geometrical characteristics of dense jets in good agreement with the past experimental studies. However, the dilution predictions are conservative. It has been observed that proximity to the bed has almost no appreciable effects on the behavior of 45° jets. However, for 30° jets, when the bed proximity parameter ( Y0/LM ) falls below 0.14, normalized values of horizontal and vertical locations of centerline peak and return point dilution are slightly reduced while the terminal rise height remains untouched.

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Section: Turbulence Modelingmentioning

confidence: 99%

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: A Numerical Study

Ramezani

Abessi

Firoozjaee

2021

Preprint

View full text Add to dashboard Cite

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“…Several turbulence models have been developed to compute these two terms. The present paper employs the realizable − model of Shih et al (1995), which has been used and validated in several studies in the context of dense jets (Kheirkhah Gildeh et al 2015;Ardalan and Vafaei 2019;Tahmooresi and Ahmadyar 2021). The formulation of the realizable − turbulence model is given by:…”

Section: Turbulence Modelingmentioning

confidence: 99%

“…Their simulations could reproduce concentration build-up at the impact point reported by Abessi and Roberts (2015); however, dilutions at the impact point and within the spreading layer were underpredicted. In a recent study, Tahmooresi and Ahmadyar (2021) examined the effects of the turbulent Schmidt number on CFD predictions of 45° inclined dense jets. They reported reducing the turbulent Schmidt number from 1.0 to 0.4 improves the dilution predictions, whereas this change adversely affects the geometrical parameters and crosssectional distribution of concentration.…”

Section: Introductionmentioning

confidence: 99%

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: a Numerical Study

2021

View full text Add to dashboard Cite

Employing inclined dense jets is a common way for the disposal of brine effluent from coastal desalination plants. This paper numerically analyzes the mixing and geometrical properties of 30° and 45° inclined dense jets when they discharge close to the bed. For this purpose, two series of numerical simulations were developed. First, the nozzle acts as a free jet when it is placed far enough from the lower boundary. Meanwhile, in the second series, the distance between the nozzle tip and seabed is substantially reduced. Consequently, by comparing these two series, the effect of proximity to bed on the behavior of dense jets is investigated. The governing equations are solved by modifying a solver within the CFD package of OpenFOAM. The numerical results are presented in comparative figures and compared to the previous works. Comparisons indicated that the numerical model predicts the geometrical characteristics of dense jets in good agreement with the past experimental studies. However, the dilution predictions are conservative. It has been observed that proximity to the bed has almost no appreciable effects on the behavior of 45° jets. However, for 30° jets, when the bed proximity parameter ( 0 ⁄ ) falls below 0.14, normalized values of horizontal and vertical locations of centerline peak and return point dilution are slightly reduced while the terminal rise height remains untouched. Keywords Dense jet . Negatively buoyant jet . Mixing . Coanda effect . CFD . OpenFOAM Article Highlights The mixing and geometrical properties of 30° and 45° inclined dense jets were numerically analyzed.  Some characteristics of 30° jets were influenced by the lower boundary.  The behavior of 45° inclined dense jets was almost insensitive to variations of the bed proximity parameter.  The RANS approach was able to predict geometrical characteristics while dilution predictions were conservative.

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“…In simulating INBJs using CFD, two approaches have been used: Reynolds-averaged Navier-Stokes (RANS) equations and Large-eddy simulation (LES).In RANS studies, both eddy viscosity models (EVM) and Reynolds stress models (RSM) have been employed (e.g., [22,[38][39][40][41][42][43]), with most studies focusing on Reynolds stress modeling, compared to the Reynolds flux modeling (SFM). This challenge was addressed in the study of Tahmooresi and Ahmadyar [22], where they used SFM approach to model the turbulent flux vector.…”

Section: Introductionmentioning

confidence: 99%

“…However, the range of this under prediction varies between more than 50% in some commercial codes with integral modeling approach ( [50]) and 20% in the LES modeling of 45 • inclined dens jets ( [44], [45], [47]). Employing the regional turbulent Schmidt number (RTSN) approach, [42] reduced this underestimation to ∼ 14% at the return point for 45 • inclined dens jets. Vafa et al [49] addressed the problem of underestimation of dilution in LES by changing the discretization schemes for convective terms of the filtered momentum and scalar transport equations.…”

Section: Introductionmentioning

confidence: 99%

Reynolds flux modeling; new numerical insights into inclined dense jets

et al. 2023

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This paper aims to provide a more detailed representation of the scalar flux modeling (SFM) approach for modeling turbulent inclined negatively buoyant jets. The SFM approach addresses the limitations of eddy viscosity models in terms of the mean concentration field and turbulent scalar flux within the context of Reynolds-averaged Navier-Stokes modeling. In this study, the contribution of the involved terms in the transport equation of the turbulent scalar flux vector was evaluated, and the geometrical and mixing parameters of concentration and velocity of 45 • inclined negatively buoyant jets were verified. The SFM approach, along with the required modification for momentum flux modeling, was implemented in OpenFOAM v6. Results showed that the SFM approach can accurately predict mixing parameters due to the complex interactions between different turbulence contributors of the flow involved in the model. In comparison to simpler approaches, such as gradient-type models, that only correlate the gradient of the scalar field with turbulence, the SFM approach's capability to predict mixing parameters is significantly higher.

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Effects of turbulent Schmidt number on CFD simulation of $$45^\circ $$ inclined negatively buoyant jets

Cited by 14 publications

References 44 publications

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: A Numerical Study

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: A Numerical Study

Effect of Proximity to Bed on 30° and 45° Inclined Dense Jets: a Numerical Study

Reynolds flux modeling; new numerical insights into inclined dense jets

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