We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Papers
61,005 resultsShowing papers similar to Settling processes of cylindrical microplastics in quiescent water: A fully resolved numerical simulation study
ClearImproved Settling Velocity for Microplastic Fibers: A New Shape-Dependent Drag Model
A new shape-dependent drag model was developed to improve the accuracy of settling velocity predictions for microplastic fibers, addressing a major limitation of existing drag models that significantly underpredict fiber settling in aquatic environments.
Settling of nonuniform cylinders at intermediate Reynolds numbers
This study investigated the settling behavior of non-uniform cylindrical particles at intermediate Reynolds numbers, providing new data on how particle shape and aspect ratio influence drag and settling velocity. The findings are relevant to predicting the transport and deposition of microplastic fibers in water.
Settling velocity of submillimeter microplastic fibers in still water
The settling velocity of 519 submillimeter microplastic fibers (300-600 micrometers long) was measured in still water, finding that settling rates vary considerably by fiber length and orientation, informing models of microplastic fiber transport and deposition in aquatic systems.
Settling velocity of microplastic particles having regular and irregular shapes
Researchers measured how quickly microplastic particles of various shapes settle through water, testing 66 different particle types including spheres, cylinders, fibers, and irregular fragments. They found that particle shape significantly affects settling speed, with fibers and flat shapes sinking more slowly than spheres of the same size. The study provides new equations for predicting where microplastics end up in oceans and waterways based on their shape.
Towards better predicting the settling velocity of film-shaped microplastics based on experiment and simulation data
Researchers combined experimental and simulation data to better predict how film-shaped microplastics settle through water, since most existing models are based on spherical particles. They found that the particle definition approach was more suitable than equivalent spherical diameter for characterizing flat, irregular microplastics. The improved settling velocity predictions could help scientists better understand how film-shaped microplastics travel and accumulate in aquatic environments.
Settling velocity of microplastic particles of regular shapes
This study measured the sinking velocities of spherical, cylindrical, and filament-shaped microplastic particles ranging from 0.5 to 5 mm, finding that shape strongly determines how quickly particles settle through the water column. Understanding settling behavior is essential for modeling how microplastics are transported and deposited in marine environments.
Inertial settling of an arbitrarily oriented cylinder in a quiescent flow : from short-time to quasi-steady motion
This study modeled the inertial settling behavior of cylindrical particles — which can represent microplastic fibers — falling through still water. Researchers derived mathematical expressions for how cylinders orient and accelerate during settling at both short and long time scales. Understanding how fiber-shaped microplastics settle is important for predicting where they accumulate in aquatic environments.
A settling velocity formula for irregular shaped microplastic fragments based on new shape factor: Influence of secondary motions
Researchers developed a new shape factor for irregular microplastic fragments and derived a settling velocity formula based on it, using numerical modeling to show that fragment shape governs whether particles sink stably or oscillate — providing more accurate predictions of microplastic transport in rivers and lakes than existing methods.
Gravitational settling of microplastic fibers: experimental results and implications for global transport
This study measured the gravitational settling velocities of microplastic fibers and found that their non-spherical shape causes them to settle much more slowly than spheres of the same volume. Current atmospheric transport models that assume spherical particles significantly underestimate how long fibers remain airborne. These results have important implications for predicting how far microplastic fibers can travel before depositing.
Prediction of the settlement of submillimeter microplastic fibers in still water
Using fluid dynamics simulations validated by experiments, researchers modeled how submillimeter synthetic textile fibers sink through still water, finding that standard drag equations (Stokes law) apply when fibers orient horizontally. They developed an improved drag model that accounts for fiber orientation, enabling more accurate predictions of where microfibers ultimately settle in lakes, rivers, and oceans. Knowing where fibers accumulate helps identify which aquatic habitats and organisms face the greatest exposure.
Characteristics and Sinking Behavior of Typical Microplastics Including the Potential Effect of Biofouling: Implications for Remediation
Researchers characterized how microplastics of different shapes sink through water, finding that shape is a critical factor, with films behaving very differently from spheres and fibers. The study also examines how biofouling on floating plastics can cause them to sink, with implications for designing filtration and remediation systems.
Settling velocities of microplastics with different shapes in sediment-water mixtures
Researchers studied how the shape of microplastic particles affects how quickly they sink in water containing suspended sediment. They found that fibers and films settle much more slowly than fragments and pellets, and that sediment in the water significantly slows the settling of all microplastic types. These findings are important for predicting where microplastics accumulate in lakes, rivers, and oceans.
Towards realistic predictions of microplastic fiber transport in aquatic environments: Secondary motions
Researchers developed an improved drag model for predicting microplastic fiber settling in water by incorporating secondary motions including tumbling and oscillation in addition to the standard drag forces. Secondary motions profoundly affect settling trajectories and deposited positions, and the new model outperforms existing approaches that neglect these behaviors.
Empirical Shape-Based Estimation of Settling Microplastic Particles Drag Coefficient
This study experimentally measured the settling behavior of flat square microplastic particles in water, finding that shape significantly affects sinking speed and drag compared to spherical particles. Understanding how microplastic shapes influence settling is essential for modeling where plastics accumulate in rivers and ocean sediments.
Coupled CFD-DEM modelling to assess settlement velocity and drag coefficient of microplastics
Researchers used computational fluid dynamics coupled with particle simulations to model how the size, shape, and density of microplastics affect their settling velocity and drag in water. Accurate physical models of microplastic behavior are essential for predicting where particles accumulate in rivers, lakes, and the ocean.
Modeling the settling and resuspension of microplastics in rivers: Effect of particle properties and flow conditions
Researchers developed a mathematical model to simulate how microplastics of different shapes settle and resuspend in rivers, moving beyond the common assumption that all particles are spherical. They found that turbulence has a complex effect, sometimes keeping particles suspended longer and sometimes accelerating their settling, depending on flow conditions. The model reveals that particle shape significantly influences where microplastics end up in river systems.
Settling velocity of irregularly shaped microplastics under steady and dynamic flow conditions
The settling velocities of irregularly shaped microplastics were measured under both still water and dynamic flow conditions, finding that shape strongly affected settling speed and that turbulence caused non-spherical particles to orient and settle differently than spheres, with implications for predicting microplastic vertical transport in rivers and coastal waters.
Settling Velocities of Small Microplastic Fragments and Fibers
Researchers precisely measured the settling speeds of over 4,000 small microplastic particles in water and found that existing prediction models designed for larger microplastics do not work well for these tiny fragments and fibers. The settling speed depends on each particle's size, density, and shape, with the smallest particles sinking extremely slowly. Understanding how quickly microplastics settle in water is important because it determines how far they travel and how long they remain available to be consumed by aquatic organisms that humans may eventually eat.
Systematic Evaluation of Physical Parameters Affecting the Terminal Settling Velocity of Microplastic Particles in Lakes Using CFD
Researchers used computational fluid dynamics to systematically evaluate how physical parameters including size, shape, density, and surface roughness affect microplastic settling velocity in lakes, finding that particle shape and density are the most influential factors determining residence time.
Effects of Particle Properties on the Settling and Rise Velocities of Microplastics in Freshwater under Laboratory Conditions
Physical experiments quantified the settling and rise velocities of ~500 microplastic particles of varying shapes, sizes, and densities under controlled laboratory conditions, finding velocities ranging from 0.39 cm/s (settling polyamide fibers) to 31.4 cm/s (rising expanded polystyrene), with standard sediment transport formulas inadequate for fibers. The study provides empirical data needed to improve models of microplastic transport in rivers and lakes.
Modeling Microplastic Transport in the Marine Environment: Testing Empirical Models of Particle Terminal Sinking Velocity for Irregularly Shaped Particles
Researchers tested multiple drag models for predicting the terminal settling velocity of irregularly shaped microplastic particles in seawater, identifying three high-precision models and demonstrating that settling velocity is largely stable across ocean depths and independent of initial particle velocity, improving the accuracy of marine microplastic transport simulations.
Machine learning-based prediction for settling velocity of microplastics with various shapes
Researchers developed machine learning models to predict the settling velocity of microplastics based on their size, density, and shape. They classified microplastic shapes into fiber, film, and fragment categories and identified the optimal shape parameter for each, achieving significantly better prediction accuracy than existing theoretical models. The study reveals that particle size has the greatest influence on settling velocity, which is important for understanding how microplastics move and distribute in water environments.
Controlling factors of microplastic fibre settling through a water column
Using particle tracking velocimetry, researchers measured the settling velocity of 683 polyester microplastic fibers and found that fiber length, curliness, and settling orientation all control descent through water. Curly fibers settled up to 1.75 times slower than straight fibers of equal length, and the low settling velocities (0.1 to 0.55 mm/s) suggest microplastic fibers are prone to biological flocculation and prolonged suspension in the water column.
Towards A universal settling model for microplastics with diverse shapes: Machine learning breaking morphological barriers
Researchers developed a machine learning model to predict the settling velocity of microplastics across different shapes, including fragments, films, and fibers. Unlike existing models limited to specific morphologies, this approach works universally across all three particle types. The study provides a more reliable tool for modeling how microplastics move through and deposit in aquatic environments.