An investigation into the applicability of the Lattice Boltzmann method to modelling of the flow in a hydrocyclone
- Bhamjee, Muaaz, Connell, S. H., Nel, Andre L.
- Authors: Bhamjee, Muaaz , Connell, S. H. , Nel, Andre L.
- Date: 2014
- Subjects: Hydrocyclone , LBM , CFD , Multiphase , Air-Core , LES
- Type: Article
- Identifier: uj:4721 , http://hdl.handle.net/10210/11434
- Description: The lattice Boltzmann method has gained popularity as a method for simulating fluid flow, particularly multiphase flow. Thus, it has potential in simulating fluid flow in hydrocyclones. While research on the method and its’ application to multiphase flow is mature, there is sparse research on its’ application to hydrocyclones. An overview of the literature on the use of the lattice Boltzmann method for simulating fluid flow in hydrocyclones is presented. A lattice Boltzmann model of single phase flow in a hydrocyclone is presented, which is compared to predictions from a Navier-Stokes based model. The lattice Boltzmann model predicts lower velocities than the Navier-Stokes model in certain areas of the hydrocyclone and higher velocities in other areas. In some areas both models are in close agreement. The lattice Boltzmann model predicts the low pressure region at the underflow and overflow. However, it does not display the low pressure region in the core of the hydrocyclone. It is proposed that these differences are related to the use of the single relaxation time implementation of the lattice Boltzmann method. The possible solution is to use the multiple relaxation time model which is more suitable to high-Reynolds number flows.
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- Authors: Bhamjee, Muaaz , Connell, S. H. , Nel, Andre L.
- Date: 2014
- Subjects: Hydrocyclone , LBM , CFD , Multiphase , Air-Core , LES
- Type: Article
- Identifier: uj:4721 , http://hdl.handle.net/10210/11434
- Description: The lattice Boltzmann method has gained popularity as a method for simulating fluid flow, particularly multiphase flow. Thus, it has potential in simulating fluid flow in hydrocyclones. While research on the method and its’ application to multiphase flow is mature, there is sparse research on its’ application to hydrocyclones. An overview of the literature on the use of the lattice Boltzmann method for simulating fluid flow in hydrocyclones is presented. A lattice Boltzmann model of single phase flow in a hydrocyclone is presented, which is compared to predictions from a Navier-Stokes based model. The lattice Boltzmann model predicts lower velocities than the Navier-Stokes model in certain areas of the hydrocyclone and higher velocities in other areas. In some areas both models are in close agreement. The lattice Boltzmann model predicts the low pressure region at the underflow and overflow. However, it does not display the low pressure region in the core of the hydrocyclone. It is proposed that these differences are related to the use of the single relaxation time implementation of the lattice Boltzmann method. The possible solution is to use the multiple relaxation time model which is more suitable to high-Reynolds number flows.
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Design life cycle of a 3-D printed hydrocyclone
- Tina, Sandrine A. Tcheuhebou, Bhamjee, Muaaz, Nel, Andre L.
- Authors: Tina, Sandrine A. Tcheuhebou , Bhamjee, Muaaz , Nel, Andre L.
- Date: 2016
- Subjects: Additive manufacturing , 3-D printing , Particle separation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93155 , uj:20314 , Citation: Tina, S.A.T., Bhamjee, M. & Nel, A.L. 2016. Design life cycle of a 3-D printed hydrocyclone.
- Description: Abstract: In mineral processing solid-fluid mixtures are separated in various ways. Of these, hydrocyclones are found to be a simple and low cost technique for particle separation. Additive Manufacturing (AM) technology has the potential to improve the design and testing process for hydrocyclones. The aim of this study is to evaluate the effectiveness of using AM and surface treatments to optimise hydrocyclone design. The hydrocyclone used in these experiments is based on a commercial model used in practice. The hydrocyclone was manufactured with a common plastic material (ABS+) and was fabricated by use a Rapid Prototyping Additive Manufacturing (RPAM) technique. This paper describes the 3-D design printing (3DDP) and manufacture of a hydrocyclone design based on a commercial design using RPAM and a surface protection process. Based on the results of this study, this process has the potential to reduce development time and cost to produce an optimal hydrocyclone design iteration.
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- Authors: Tina, Sandrine A. Tcheuhebou , Bhamjee, Muaaz , Nel, Andre L.
- Date: 2016
- Subjects: Additive manufacturing , 3-D printing , Particle separation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93155 , uj:20314 , Citation: Tina, S.A.T., Bhamjee, M. & Nel, A.L. 2016. Design life cycle of a 3-D printed hydrocyclone.
- Description: Abstract: In mineral processing solid-fluid mixtures are separated in various ways. Of these, hydrocyclones are found to be a simple and low cost technique for particle separation. Additive Manufacturing (AM) technology has the potential to improve the design and testing process for hydrocyclones. The aim of this study is to evaluate the effectiveness of using AM and surface treatments to optimise hydrocyclone design. The hydrocyclone used in these experiments is based on a commercial model used in practice. The hydrocyclone was manufactured with a common plastic material (ABS+) and was fabricated by use a Rapid Prototyping Additive Manufacturing (RPAM) technique. This paper describes the 3-D design printing (3DDP) and manufacture of a hydrocyclone design based on a commercial design using RPAM and a surface protection process. Based on the results of this study, this process has the potential to reduce development time and cost to produce an optimal hydrocyclone design iteration.
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Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization
- Robinson, Philip E., Nel, Andre L.
- Authors: Robinson, Philip E. , Nel, Andre L.
- Date: 2016
- Subjects: Atmospheric turbulence , Video stabilization , Background subtraction
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/217644 , uj:21665 , Citation: Robinson, P.E. & Nel, A.L. 2016. Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization.
- Description: Abstract: Video sequences captured over a long range through the turbulent atmosphere contain some degree of atmospheric turbulence degradation (ATD). Stabilization of the geometric distortions present in video sequences containing ATD and containing objects undergoing real motion is a challenging task. This is due to the difficulty of discriminating what visible motion is real motion and what is caused by ATD warping. Due to this, most stabilization techniques applied to ATD sequences distort real motion in the sequence. In this study we propose a new method to classify foreground regions in ATD video sequences. This classification is used to stabilize the background of the scene while preserving objects undergoing real motion by compositing them back into the sequence. A hand annotated dataset of three ATD sequences is produced with which the performance of this approach can be quantitatively measured and compared against the current state-of-the-art.
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- Authors: Robinson, Philip E. , Nel, Andre L.
- Date: 2016
- Subjects: Atmospheric turbulence , Video stabilization , Background subtraction
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/217644 , uj:21665 , Citation: Robinson, P.E. & Nel, A.L. 2016. Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization.
- Description: Abstract: Video sequences captured over a long range through the turbulent atmosphere contain some degree of atmospheric turbulence degradation (ATD). Stabilization of the geometric distortions present in video sequences containing ATD and containing objects undergoing real motion is a challenging task. This is due to the difficulty of discriminating what visible motion is real motion and what is caused by ATD warping. Due to this, most stabilization techniques applied to ATD sequences distort real motion in the sequence. In this study we propose a new method to classify foreground regions in ATD video sequences. This classification is used to stabilize the background of the scene while preserving objects undergoing real motion by compositing them back into the sequence. A hand annotated dataset of three ATD sequences is produced with which the performance of this approach can be quantitatively measured and compared against the current state-of-the-art.
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