The investigation of fluids containing particles or filaments includes a category of complex fluids and is vital in both theory and application. The forecast of particle behaviours plays a significant role in the existing technology as well as future technology.
The present work focuses on the prediction of the particle behaviour through the investigation of the particle disentrainment from a pipe on a horizontal air stream. This allows for examining the influence of the particle physical properties on its behaviour when falling on horizontal air stream. This investigation was conducted on a device located at the University of Greenwich's Medway Campus. Two materials were selected to carry out this study: Salt and Glass Beads Nano particles. The shape of the Slat particles is cubic where the shape of the Glass Beads is almost spherical. The outcome from the experimental work were presented in terms of distance travelled by the particles according to their diameters as After that, the particles sizes were measured using Laser diffraction device and used to determine the drag coefficient and the settling velocity.
For a verification and more deep insight, the experimental setup was modelled using Computational Fluid Dynamics (CFD) technique and the results were compared with the experimental results in terms of distance travelled. A good agreement was observed between the CFD and experimental results. The experimental and numerical results showed that the size of the particle has a huge impact on the drag coefficient and the settling velocity. Larger diameters lead to less drag and hence higher settling velocity. Also, the lighter particles tent to travel horizontally further than the heavier ones.
Table of Contents
1 Introduction
2 Problem Statement
3 Aim and objectives
4 Literature Review
4.1 Introduction
4.2 Fluid-solid mixture
4.3 Calculation methods of spherical particles settling velocity
5 Test apparatus
5.1 Chamber
5.2 Air delivering
5.3 Laser diffraction
6 Experimental methodology
6.1 Preparation
6.1.1 Safety
6.1.2 Setup
6.2 Martials
6.2.1 Salt
6.2.2 Glass beads
6.2.3 Air properties
6.3 Experiment
6.3.1 Assumption
6.3.2 Testing
7 Result &Discussion
7.1 Experimental results
7.1.1 Salt results
7.1.2 Glass beads results
7.2 Hand calculation results
7.3 CFD modelling
7.3.1 Methodology
7.3.2 CFD modelling results
8 Conclusion
9 Future work& Recommendations
Project Goals and Scope
This project aims to investigate the physical interaction between particles and a horizontal air stream to understand the factors influencing particle settling behavior and to determine the drag coefficient of spherical particles using both experimental measurements and Computational Fluid Dynamics (CFD) modeling.
- Analysis of particle settling dynamics in a horizontal flow chamber.
- Evaluation of the influence of particle physical properties on sedimentation.
- Experimental testing using Salt and Glass Beads to obtain settling velocity data.
- Development of a two-dimensional CFD model to verify and simulate experimental results.
Excerpt from the Book
1 Introduction
The investigation of fluids containing particles or filaments includes a class of complex fluids and is vital in both theory and application. Several studies have focused on the particle behaviour in a fluid flow. The forecast of particle behaviours plays a significant role in several engineering processes and fields, for example, chemical and metallurgical processes as well as mechanical and environmental engineering. Modelling of the particle in water process requires deep knowledge of predicting the particle velocity. In the gas turbine, blades and nozzles are exposed to erosion which is strongly rely on the particles velocities. A further application is the transmission of bulk material via pneumatic conveying, the assumption made for the particle motion is based on the terminal velocity of the particles. This emphasise the significance of predicting such velocity for selecting the right sizing and the appropriate design of the plant.
Regardless of such significance, the existing investigation do not offer a sufficient insight on such subject and enhancements of the prediction of the particles behaviours which in turns can lead to more accurate mathematical models. Also, the greater part of the existing studies is centred around the investigation of particles having regular shapes such as sphere (the least difficult and most researched shape), cubical or cylindrical shapes. Furthermore, the used material in these studies are fairly limited due to the irregular shape of their particles.
The present work focuses on the prediction of the particle behaviour through the investigation of the particle disentrainment from a horizontal air stream. The objective of the current study is to examine the effect of the particle properties on disentrainment on an air stream. The study was conducted using mechanical assembly which is located at the University of Greenwich's Medway Campus which is shown in Figure 1. Two different materials were considered in the current study, Salt, and Glass beads, were selected for their almost perfect spherical shapes. This experiments were repeat few times in order to verify the results and performances. Later on, the results were compared with the hand calculations and were further used to produce a two-dimensional Computational Fluid Dynamics (CFD) model.
Summary of Chapters
1 Introduction: Provides an overview of the importance of studying particle behavior in fluid flows and defines the objectives of the research project.
2 Problem Statement: Discusses the challenges of understanding particle movement in industrial and natural environments and highlights the need for better scientific models.
3 Aim and objectives: Outlines the primary goals, including the experimental investigation of particle settling and the creation of a supportive CFD model.
4 Literature Review: Summarizes existing research on particle technology, fluid-solid mixtures, and established methods for calculating terminal settling velocity.
5 Test apparatus: Describes the mechanical design and functionality of the horizontal elutriator used for testing particle disentrainment.
6 Experimental methodology: Details the safety procedures, setup, material properties, and experimental steps involved in data collection.
7 Result &Discussion: Presents the experimental findings, hand calculations, and CFD modeling results, including a comparative analysis.
8 Conclusion: Synthesizes the main findings, confirming the successful validation of the CFD model against experimental data regarding particle size and drag.
9 Future work& Recommendations: Suggests potential avenues for further research, such as testing different particle shapes and varied air velocities.
Keywords
Particle settling, fluid dynamics, CFD, horizontal air stream, drag coefficient, sedimentation, Salt, Glass Beads, terminal velocity, laminar flow, particle disentrainment, computational modeling, particle behavior, industrial engineering.
Frequently Asked Questions
What is the core focus of this research project?
The project investigates how physical particles behave when subjected to a horizontal air stream, specifically focusing on disentrainment and settling patterns.
What are the primary subjects addressed in the study?
The study covers particle technology, fluid-solid mixtures, the design of test apparatus for granular materials, and the comparative analysis of experimental vs. numerical fluid data.
What is the main objective of the work?
The main goal is to analyze the influence of particle properties, such as size and shape, on their settling velocity and to determine their drag coefficients in a controlled environment.
Which scientific methods are employed?
The research uses an experimental approach involving a horizontal elutriator and a numerical approach utilizing ANSYS FLUENT for Computational Fluid Dynamics (CFD) modeling.
What is covered in the main section of the document?
The main body details the test apparatus, the experimental procedure (testing Salt and Glass Beads), the calculation of drag coefficients, and the validation of results through CFD simulations.
What are the key terms associated with this work?
Key terms include Particle settling, CFD, drag coefficient, horizontal air stream, sedimentation, and laminar flow.
Why were Salt and Glass Beads selected as materials?
They were selected specifically for their nearly perfect spherical shapes, which allow for more accurate comparison with established theoretical drag and settling models.
How does particle diameter affect the results?
The study demonstrates that larger particle diameters result in lower drag and consequently higher settling velocities, meaning they tend to descend faster than lighter, smaller particles.
How did the CFD results compare to the experimental data?
A good general agreement was observed between the experimental measurements and the CFD model results, validating the efficacy of the 2D computational approach used.
What does the author suggest for future improvements?
Recommendations include experimenting with different particle shapes and testing at varying air velocities to further refine the understanding of particle motion in turbulent regimes.
- Quote paper
- Abdulrahman Alenezi (Author), 2019, Evaluation of particle settling in flow chamber, Munich, GRIN Verlag, https://www.grin.com/document/537441
