Inertial Dust Research Articles

Modulational instability and associated low-frequency dust-acoustic waves in a degenerate Thomas-Fermi plasma: Envelope solitons and rogue waves

This paper examines the modulational instability (MI) of low-frequency dust-acoustic waves in a dusty quantum plasma that contains inertial dust particles and inertialess Thomas-Fermi distributed ions and electrons. In this model, the ions and electrons are assumed to be in a degenerate quantum state. By using a reductive perturbation technique, the fluid governing equations are reduced to an evolutionary equation (say, a nonlinear Schrödinger equation that governs this phenomenon). A detailed investigation is carried out on the dispersion relation, group dispersion coefficient, nonlinearity coefficient, and the regions of the MI. Regions of stability and instability are precisely determined based on the MI criteria and the pertinent physical parameters of the model under examination. We also examine some nonlinear modulated phenomena (localized envelope structures), such as dark, bright envelope solitons, rogue waves, and breathers that can propagate in stable and unstable regions.

The impact of polarization force on the oblique propagation of dust-acoustic solitons in a superthermal complex magnetoplasma

This work aims to examine the (non)linear properties of the dust-acoustic waves (DAWs) in a polarized superthermal complex magnetoplasma. The existing plasma model consists of inertial dust grains and inertialess electrons and ions. The electrons in this model adhere to the Maxwell–Boltzmann distribution, while the ions conform to the superthermal distribution. It is postulated that the electrostatic waves propagate obliquely with the magnetic field. The Sagdeev potential approach is employed to reduce the basic model equations to an equivalent energy balance equation. It is shown how the existence domain and the properties of large amplitude obliquely propagating dust-acoustic solitary waves (DASWs) are affected via the characteristic relevant plasma parameters. The implication of the study is highlighted to the space dusty plasma.

Exploring dust-ion acoustic shocks in a plasma in the light of phase plane analysis

This paper presents a comprehensive exploration of shock waves in a dusty plasma, incorporating the dynamics of inertial dust and ions with Maxwellian distributed electrons. By deriving the Korteweg-de Vries-Burgers (KdV-B) equation and by using its standard solution we analyze the characteristics of the shock front under varying parameters. Furthermore, we conduct a phase plane analysis to elucidate the system's behavior and dynamics by tuning in the parameters that provide various types of perturbation in the system. The investigation sheds light on the intricate behavior of shock waves in dusty plasmas and contributes valuable insights to the understanding of plasma dynamics.

Innovative technologies combating with dust emission releasing into the atmosphere

An examination of various approaches, methods, and technologies recommended as optimal for safeguarding atmospheric air against dust pollution has led to the identification of the distinct advantages associated with vortex inertial dust collectors utilizing swirling currents. These collectors, referred to as Cyclone Separation Fans (CSF), have been determined to serve as primary and auxiliary equipment in dust removal systems within the production of building materials and other industries. Traditionally employed circuit designs for dust collection systems were also subject to analysis, revealing two prevalent types: open and partially closed air circulation systems. In the latter, a portion of the cleaned airflow is reintroduced into the system, representing a key feature of the design. This assessment underscores the significance of vortex inertial dust collectors, specifically CSFs, as instrumental components in dust removal systems across various industrial sectors. Their effectiveness in mitigating dust pollution, coupled with their versatility as both primary and supplementary equipment, positions them as recommended technologies for atmospheric air protection in the production of building materials and other related industries. The recognition of open and partially closed air circulation systems in traditional dust collection circuit designs further contributes to refining and optimizing dust removal processes for enhanced environmental protection.

Technical Solutions to Reduce the Amount of Dust Particle Breakthrough when Cleaning Emissions from the Production of Reinforced Concrete Products Using Dust Collectors with Counter Swirling Flows

Introduction. The production of reinforced concrete products, being the basis of modern industrial construction, is a very significant source of dust emissions. Traditional cleaning methods are often unable to ensure the compliance with air quality requirements, and replacing them with more modern ones requires significant capital and operational costs. One of the most promising ways to solve the problem is the use of a new class of inertial dust collectors with counter swirling flows, combining constructive simplicity and low operating costs with sufficiently high work efficiency. The aim of the work was to analyze the factors influencing the magnitude of the breakthrough coefficient of fine dust particles, as well as the development of constructive solutions aimed at reducing it. Materials and Methods. An analytical review of technical solutions aimed at reducing the breakthrough magnitude was carried out, on the basis of which the designs of the lower input of dust collectors with counter swirling flows were developed. Methods of computational experiment and field measurements were used to confirm the effectiveness of the developed structures. Results. By means of numerical experiments, the information about the aerodynamic flow pattern in the separation chamber of the CSF dust collector was obtained, and the breakthrough magnitude of dust particles was estimated. The solutions were developed for the design of the lower coaxial input of the swirling flow of dust collectors on the counter swirling flows, taking into account the features of dust pollution generated during the operation of technological equipment of reinforced concrete production. Discussion and Conclusion. The presence of a displacement of the axis of the secondary swirling flow from the axis of symmetry of the separation chamber was established. The consequence of this was the non-coaxiality of the primary and secondary flows, which led to a decrease in the intensity of the twist, the formation of parasitic vortices, and, as a consequence, an increase in the value of the breakthrough coefficient. This effect was especially pronounced with a large proportion of fine dust particles, characteristic of dust pollution formed during the production of reinforced concrete products. The proposed design of the coaxial input of the secondary swirling flow reduced the magnitude of this eccentricity, which made it possible to achieve a significant reduction in the breakthrough magnitude of fine particles characteristic of dust emissions of reinforced concrete industries. The results obtained can be effectively used both in the production of reinforced concrete products and in other branches of construction production, which is characterized by intensive formation of fine dust emissions.

Dynamics of pulsational mode in the EiBI gravity fabric

We systematically theorise a model formalism to investigate the linear pulsational mode dynamics excitable in self-gravitating dust molecular clouds (DMCs) in the framework of the Eddington-inspired Born-Infeld (EiBI) gravity. The adopted spherical DMC consists of thermalized lighter (non-inertial) electrons and ions, both treated analogously as the Boltzmann species, whereas the partially ionised heavier (inertial) dust grains as the constitutive neutral and charged dust fluids. The model closure comes from the coupling gravito-electrostatic Poisson equations governing the resultant potential distributions sourced in the material and charge density fields. Application of spherical normal mode (Fourier-based) analysis transforms the model DMC into a quartic linear dispersion relation with diverse atypical multi-parametric dispersion coefficients. A numerical platform is constructed for an illustrative dispersion analysis. It shows that the positive EiBI parameter, dust charge number, and cloud size act as stabilizing agents against the inward non-local self-gravity. In contrast, a negative EiBI parameter, dust mass, and equilibrium dust population density play destabilizing roles. The modal propagatory and oscillatory features are portrayed graphically and interpreted elaborately. The reliability of our calculation scheme is validated in light of the closely related results previously reported in the literature. The analyses presented here could be relevant in the context of understanding astrophysical structure formation dynamics through the self-gravitational canonical condensation processes in diverse real astronomic environs.

АНАЛИЗ КОНСТРУКЦИЙ ПНЕВМОСЕПАРИРУЮЩИХ СИСТЕМ

One of the main methods of separating a grain heap is pneumatic separation based on the difference in the aerodynamic resistance of the components of the grain mixture to the air flow. A classification of pneumatic separating devices is given according to the following parameters: method of air flow circulation, number of separating channels, method of using systems, direction of air flow in separating channels and chambers, method of supplying air to the pneumatic separation zone, frequency of processing, shape of pneumatic separating channels, method of feeding grain mixture into the channel , type of devices for separating light impurities, method of regulating air flow in the channel. The formulas developed by different authors for the coefficient of particle resistance to air flow are generalized. The optimal dimensions of the pneumatic channel have been established: the depth of the channel should not exceed 200 mm, and the width should not exceed 1500 mm. It has been established that the most commonly used shape of the pneumatic channel is rectangular. It is shown that various devices are used to introduce grain material into the pneumatic channel: pitched boards, support nets, corrugated rollers, spreading discs, vibration, belt, pneumatic, and combined devices. According to the direction of the air flow, separators are distinguished: vertical, inclined, horizontal. It has been established that louvered inertial dust collectors are usually used to clean the air from dust. The most modern designs of cross-flow fans are considered. Based on the analysis performed, recommendations were given to developers of aspiration systems: to ensure a margin of pneumatic channel width so that with an increase in the supply of grain material, the efficiency of air cleaning does not decrease, but at the same time the uniformity of the air flow in the pneumatic channel does not decrease.

Higher-order dust kinetic Alfvén wave solitons and quasi-periodic waves in a polarized dusty plasma

This investigation presents the study of dust kinetic Alfvén wave solitons (DKAWSs) and quasi-periodic waves in a polarized dusty plasma comprising inertial dust, Cairns–Tsallis (CT) distributed ions and electrons. Using the reductive perturbation method, the KdV equation is derived and the Tanh-method is employed to derive its solution to study the dust kinetic Alfvén solitary structures. Furthermore, by considering the contribution of higher-order effects, the KdV-type inhomogeneous equation is derived and its solution results in the formation of dressed DKAWSs. The combined effects of polarization force and other plasma parameters on the characteristics of different kinds of DKAWSs are analyzed. Most importantly, from the conservation of KdV equations in the presence of external periodic perturbations, the study of quasi-periodic wave has also been illustrated. The analysis shows that the periodic solitonic behavior is transformed to quasi-periodic and also approaches chaotic oscillations. By changing different physical parameters, the numerical analysis of nonlinear DKAWs from periodic to quasi-periodic and to chaotic behavior has also been presented with external perturbation. The findings of this investigation are useful to understand the insight into physics of nonlinear phenomena for studying the dynamics of DKAWSs in space and astrophysical plasma environments.

Fluid simulation of dust-acoustic solitary waves in the presence of suprathermal particles: Application to the magnetosphere of Saturn

The observation of dust in the rings of Saturn by instruments on board the Voyager 1, Voyager 2, and Cassini missions triggered our interest in exploring the evolution of electrostatic dust acoustic waves (DAWs) in the Saturnian magnetospheric dusty plasma. The salient features of dust-acoustic electrostatic solitary waves have been examined by means of numerical simulations that adopted a fluid algorithm. We considered highly energetic non-Maxwellian ion and electron populations, in combination with inertial dust. The ions and electrons were modeled by kappa distributions to account for the long-tailed particle distribution featuring a strong suprathermal component. At equilibrium, the initial density perturbation in the dust density was used to trigger the evolution of DASWs propagating in non-Maxwellian dusty plasma. Our main focus is to determine the comprehensive role of the dust concentration and the suprathermal index (kappa) of the ion and electron populations in the generation and evolution of DASWs. These simulation results are thought to be relevant for (and applicable in) existing experimental data in space, especially in the magnetosphere of Saturn, but also in other planetary plasma environments that are presumably characterized by the presence of charged dust.

Dust-acoustic periodic travelling waves in a magnetized dusty plasma with trapped ions and nonthermal electrons in astrophysical situations: oblique excitations

Obliquely propagating three-dimensional dust-acoustic periodic travelling waves (DAPTWs) in a magnetized dusty plasma composed of negatively charged inertial dust particles, trapped ions, and nonthermal fast electrons have been undertaken. In the dusty plasma model at hand, the dynamic behaviors of DAPTWs are governed by a Schamel equation. The presence of dust acoustic solitary waves (DASWs) and DAPTWs is investigated via bifurcation analysis of the Hamiltonian system. In the nonlinear regime, the Sagdeev potential and phase portrait structures indicate the presence of small-amplitude DAPTW solutions. The influences of intrinsic physical parameters include the strength of the static magnetic field, the obliqueness of propagation, the thermal pressure of charged dust grains, the electron to dust density ratio, the trapping parameter of trapped ions, and the degree of nonthermality of fast electrons on the characteristics of DAPTWs are simulated numerically. In particular, the findings illustrate that the amplitude of DAPTWs is reduced as the numerical values of the trapping parameter are decreased. Interestingly, the theoretical simulations of numerical results can significantly highlight the physical nature of DAPTWs in astrophysical situations such as Earth’s magnetosphere, auroral region, and heliospheric environments.

Effect of Gurevich Polarization Force on Arbitrary Amplitude Dust-Acoustic Waves and Double-Layer Structures in a Collisionless Complex Plasma

In this article, we have investigated the effect of the Gurevich polarization force on both large-amplitude dust-acoustic (DA) solitary waves and double-layer (DL) structures in a collisionless complex plasma. To do this, we have redefined the 3-D Gurevich distribution, which describes the evolution of the adiabatically trapped ions in the plasma potential well and derived the associated density and polarization force expressions. As an application, we have reviewed, using the pseudo-potential approach, the nonlinear DA solitons in an unmagnetized polarized complex plasma containing inertial dust grains, Maxwellian electrons, and adiabatically trapped ions. We have shown that the spatial profile of DA solitary waves is drastically affected by the Gurevich polarization force. In particular, we have found that due to the presence of this polarization force, the potential pulse amplitude increases while its width decreases, thus making the DA structure more spiky. For the sake of completeness, we have also analyzed the effect of the polarization force on DA-DL structures. Our numerical results have shown that both amplitude and width of rarefactive (compressive) DL DA structure decrease (increase) in the presence of polarization force.

Simulation of Internal Aerodynamics of Multi-Stage Inertial and Centrifugal Dust Collectors

Simulation of Internal Aerodynamics of Multi-Stage Inertial and Centrifugal Dust Collectors

Numerical analysis of the influence of vortex acoustic flows on the efficiency of agglomeration

It is known and experimentally proven many times that ultrasonic vibrations in the gas phase contribute to the appearance of stationary acoustic flows. Since the flows are caused by energy losses during absorption of oscillations, and they do work against the frictional forces that cause this absorption, then these flows have a vortex character. According to numerous studies and developments in the field of inertial dust separation, at a centripetal acceleration of 10 m/s2 or more, local compaction of particles is observed near the periphery of the vortex flow. Due to this, particles are captured in existing devices based on the inertial dust separation principle. In this regard, the article presents the results of theoretical studies of the potential for the use of acoustic flows for a local increase in the concentration of particles and, consequently, an increase in the efficiency of agglomeration. A model of the influence of vortex acoustic flows on the efficiency of agglomeration is proposed. As a result of the numerical analysis of the model, the fundamental possibility of a significant (more than 4 times) increase in the efficiency of ultrasonic agglomeration of submicron particles due to the formation of vortex acoustic flows in the resonant intervals was revealed.

On the dynamics of nonlinear propagation and interaction of the modified KP solitons in multicomponent complex plasmas

Dust-acoustic waves (DAWs) are analyzed in the small amplitude limit in a collisionless unmagnetized dusty plasma whose constituents are inertial dust grains, massless ions expressed by the generalized (r,q) distribution and inertialess Maxwellian electrons using the fluid theory of plasmas. The modified Kadomtsev-Petviashvili (mKP) equation is derived at a critical plasma condition for which the quadratic nonlinearity vanishes. The propagation of single soliton and interaction of two solitons are analyzed for the mKP equation in the context of plasma physics by employing Hirota bilinear formalism. The effects of the flatness parameter r and tail parameter q of the ions on the frequency of the DAWs are studied and the comparison with Maxwellian and kappa distributions is drawn. Using the plasma parameters corresponding to the Saturn’s E-ring, the range of electric field amplitude for dust-acoustic solitary waves (DASWs) for different ion distributions is calculated and is shown to agree very well with the Cassini Wideband Receiver (WBR) observations. The interaction time of two DASWs for non-Maxwellian ion distributions is estimated and shown to be fastest for the (r,q) distributed ions. The interesting feature of the interaction between compressive solitons with their rarefactive counterparts is also discussed in detail.

Study of the characteristics of the ascending vortex of the cyclone and the concentration of dust along its section

Introduction. Protection of the atmosphere is a social and economic problem inextricably linked with the task of creating comfortable conditions for human life and work. Cyclones are the most typical representatives of dry inertial dust collectors. This work is aimed at reducing energy consumption when cleaning gas with cyclones.
 
 Materials and methods. In the course of the work, analytical and experimental research methods were applied.
 
 Results. Analytical dependences of the aerodynamics of the ascending cyclone vortex have been obtained, which showed that the ascending vortex has a complex structure and the cyclone is an artificially created spiral structure, akin to such a natural phenomenon as a tornado. The obtained mathematical model was fully confirmed by experimental studies.
 
 Conclusions. The studies carried out show that the ascending vortex in the cyclone has a structure consisting of two zones. In the first zone (core), the force of the radial pressure gradient exceeds the centrifugal force, and the dust rushes towards the cyclone axis. In the second, the centrifugal force exceeds the force of the pressure gradient, and the dust is thrown to the periphery. The obtained theoretical model will make it possible to reasonably choose methods for more rational use of the expended energy and increasing the efficiency of cyclones.

Dust-Ion-Acoustic Rogue Waves in a Dusty Plasma Having Super-Thermal Electrons

The standard nonlinear Schrödinger Equation (NLSE) is one of the elegant equations to find detailed information about the modulational instability criteria of dust-ion-acoustic (DIA) waves and associated DIA rogue waves (DIARWs) in a three-component dusty plasma medium with inertialess super-thermal kappa distributed electrons, and inertial warm positive ions and negative dust grains. It can be seen that the plasma system supports both fast and slow DIA modes under consideration of inertial warm ions along with inertial negatively charged dust grains. It is also found that the modulationally stable parametric regime decreases with κ. The numerical analysis has also shown that the amplitude of the first and second-order DIARWs decreases with ion temperature. These results are to be considered the cornerstone for explaining the real puzzles in space and laboratory dusty plasmas.

Modulational instability of dust-ion-acoustic waves and associated first and second-order rogue waves in a super-thermal plasma

A proper theoretical research has been carried out to explore the modulational instability (MI) conditions of dust-ion-acoustic (DIA) waves (DIAWs) in a three-component dusty plasma system containing inertialess κ-distributed electrons, and inertial warm positive ions and negative dust grains. The nonlinear Schrödinger equation (NLSE) has been derived by employing the reductive perturbation method. The numerical analysis under consideration demonstrates two types of modes, namely, fast and slow DIA modes. The MI conditions of DIAWs and the configuration of the energetic rogue waves (RWs) associated with DIAWs in the modulationally unstable parametric regime have been rigorously changed by the variation of various plasma parameters, namely, charge, mass, temperature, and number density of the plasma species. The findings of our present investigation will be useful in understanding the criteria for the formation of electrostatic RWs in both astrophysical environments (viz., Jupiter’s magnetosphere, cometary tails, pulsar magneto-sphere, interstellar medium, Earth’s mesosphere, Saturn’s rings, etc.) and laboratory experiments.

Adapted instabilities excited in spherical magnetized viscoelastic astroclouds with extreme dust-fugacity moderations

We investigate the dynamics of the dust acoustic wave (DAW, low-fugacity) and the dust Coulomb wave (DCW, high-fugacity) in self-gravitating magnetized viscoelastic spherical dusty astroclouds. It consists of the inertial dust grains with variable charge alongside the nonthermal electrons and ions in a generalized hydrodynamic framework. A spherical wave analysis yields a unique generalized quadratic dispersion relation. The fluctuations are free from the viscoelasticity effects in the weakly coupled limit (WCL) against the strongly coupled limit (SCL). The electron concentration, dust charge, and magnetic field act as stabilizing and accelerating agencies. The ion density and nonthermality parameters show destabilizing and decelerating effects. The cloud size shows a unique stabilizing feature in the ultralow-frequency domain. Both the DAW and DCW are dispersive in the short-wavelength (acoustic) regime and nondispersive in the long-wavelength (gravitational) regime. The distinctive WCL–SCL scenarios are explicitly compared. The results show correlative consistencies in real astronomic circumstances sketchily. The dust acoustic wave (DAW) and the dust Coulomb wave (DCW) in self-gravitating magnetized viscoelastic spherical dusty astroclouds with extreme dust-fugacity moderations are explored. The spatiospectral profiles of (a) $$\Omega_{r}$$ and (b) $$\Omega_{i}$$ with $$K$$ and $$\xi$$ in the SCL (upper row) and in the WCL (lower row) of the HFR in the $$\kappa$$ -case are numerically portrayed.

Raising the Efficiency of Coagulation of Dispersed Particles by the Action of Ultrasonic Vibrations on Gas-Dispersed Flows in Inertial Dust Collectors

The authors have presented results of experiential investigations of the process of ultrasonic coagulation of dispersed particle in a swirling flow. The investigations were conducted using the proposed and developed test bed implementing a two-stage removal of fi ne particles. At the first stage (agglomeration), the formation of a swirling flow and the ultrasonic pre-coagulation of fi ne particles are ensured. At the second stage, high-efficiency trapping of particles preformed at the first stage is attained using a cyclone. As a result of the experimental investigations, the authors have established the prospects of using a two-stage removal of fi ne particles and have revealed the optimum conditions of ultrasonic action on a swirling gas-dispersed flow that ensure an enlargement of 4.5 times of particles in the range of RM2.5 particle sizes which is the most hazardous for humans.

Dust-acoustic envelope solitons in strongly coupled dusty plasmas

The propagation nature and the modulational instability (MI) criteria of low frequency amplitude modulated dust-acoustic envelope solitons are analyzed theoretically and numerically in an unmagnetized dusty plasma consisting of strongly coupled micron-sized inertial dust grains, Boltzmann distributed non-inertial electrons and ions. A hydrodynamical fluid model approach is used, based on [V. V. Yaroshenko, F. Verheest, H. M. Thomas and G.E. Morfill, New J. Phys. 11, 073013 (2009); V. V. Yaroshenko, V. Nosenko, and G. E. Morfill, Phys. Plasmas, 17, 103709 (2010)], where the strong coupling between dust grains for by an effective electrostatic pressure is accounted, which is in fact a dynamical function of the dust-density and the electrostatic potential. It is seen that the strong coupling between dust particles due to the effective electrostatic ``pressure” modifies the wavepacket stability and affects the occurrence of MI. A cubic nonlinear Schrodinger-type equation, which describes the evolution of the wavepacket’s envelope, is derived by adopting a multiscale technique for the amplitude dynamics. It is shown that long-wavelength dust-acoustic wavepackets are stable, while MI sets in beyond a carrier wavenumber threshold, which is evaluated in terms of intrinsic plasma parameters of relevance. On the other hand, the MI window is larger for higher ion density. The effect of the ion number density on MI is twofold, in that a higher ion density leads to a higher threshold (thus, the wave will be modulationally unstable for the larger values of the carrier wavenumber) but it also entails a wider instability window (hence, external perturbations must be of specific wavenumbers to trigger the instability). Numerical simulation confirms that the bright-type envelope soliton solution is stable beyond the carrier wavenumber threshold, i.e., in the modulationally unstable region, while the dark type envelope soliton is stable for wavenumbers below the threshold.