Multi-channel Cyclone Research Articles

Investigation of the interaction of particulate matter and its separation from the gas flow in a multi-channel cyclone with recirculation

Investigation of the interaction of particulate matter and its separation from the gas flow in a multi-channel cyclone with recirculation

Experimental Research of Gaseous Emissions Impact on the Performance of New-Design Cylindrical Multi-Channel Cyclone with Adjustable Half-Rings

Cyclones are widely used for separating particles from gas in energy production objects. The efficiency of conventional centrifugal air cleaning devices ranges from 85 to 90%, but the weakness of many cyclones is the low collection efficiency of particles less than 10 μm in diameter. The novelty of this work is the research of the channel-type treatment device, with few levels adapted for precipitation of fine particulate matter, acting by a centrifugal and filtration principle. Many factors have an impact on cyclone efficiency—humidity, temperature, gas (air) composition, airflow velocity and etc. Many scientists evaluated only the effect of origin and size of PM on cyclone efficiency. The effect of gas (air) composition and temperature, and humidity on the multi-channel cyclone-separator efficiency still demands contributions. Complex theoretical and experimental research on air flow parameters and the efficiency of a cylindrical eight-channel system with adjustable half-rings for removing fine-dispersive particles (<20 μm) was carried out. The impact of air humidity and temperature on air flow, and gaseous smoke components on the removal of wood ashes was analyzed. The dusty gas flow was regulated. During the experiment, the average velocity of the cyclone was 16 m/s, and the temperature was 20–50 °C. The current paper presents experimental research results of wood ash removal in an eight-channel cyclone and theoretical methodology for the calculation of airflow parameters and cyclone effectiveness.

The Numerical Modeling of Gas Movement in a Single Inlet New Generation Multi-Channel Cyclone Separator

The work of traditional cyclones is based on the separation of solid particles using only the centrifugal forces. Therefore, they do not demonstrate high gas-cleaning efficiency, particularly in the cases where gas flows are polluted with fine solid particles (about 20 µm in diameter). The key feature of a new-generation multi-channel cyclone separator’s structure is that its symmetrical upgraded curved elements, with openings cut with their plates bent outwards, make channels for the continuous movement of the gas flows from the inflow opening to the central axis. The smoke flue of the vertical gas outflow is located near the cover of the separating chamber. The present work is aimed at studying the applicability of two various viscosity models and their modified versions to simulate aerodynamic processes in an innovative design for a multi-channel cyclone separator with a single inflow, using the computational fluid dynamics. The research results obtained in the numerical simulation are compared to the experimental results obtained using a physical model. The main purpose of this study is to provide information on how the new design for the multi-channel cyclone affects the distribution of gas flow in the cyclone’s channels. The modified viscosity models, k-ε and k-ω, and computational meshes with various levels of detailed elaboration were analyzed. The developed numerical models of a single-inlet multi-channel cyclone separator allow the researchers to describe its advantages and possible methods of improving its new structure. The developed models can be used for simulating the fluid cleaning phenomenon in the improved fourth-channel cyclone separator and to optimize the whole research process.

Experimental investigation of a one-level eight-channel cyclone-separator incorporating quarter-rings

The main aim of this investigation was an experimental analysis of the air cleaning efficiency in a mock-up next-generation air cleaning device - one-level 8-channel industrial cyclone-separator with quarter-rings - while changing parameters of the inner structure and the assessment of the effects of dispersion of particulate matter. Therefore, the research was carried out in two stages: the first stage covered the analysis of the efficiency of the multi-channel cyclone with particulate matter of <20 and <50 ?m. During the second stage, a cascade impactor was used to measure the particle collection efficiency in the multi-channel cyclone by fractions: PM1, PM2.5 and PM10. Results of the tests with using the cascade impactor were compared to show changes in the PM composition before and after the multi-channel cyclone-separator. According to the obtained experimental data, the one-level 8-channel cyclone-separator collects 70 to 80 % of PM up to 10 ?m in size, 45 to 60 % of PM up to 2.5 ?m in size and 21 to 25 % of PM up to 1 ?m in size.

Removal of fine solid particles in aggressive gas flows in a newly designed multi-channel cyclone

A significant proportion of pollutants arise from the heat production equipment in private households. The processes of combustion and product treatment (drying, adding chemical compounds) generate aggressive gas flows containing solid particles (SPs). Common methods employ high-efficiency gas purification to remove SPs, the most popular include electrostatic and sleeve-type filters. However, the operation of these types of filters is complex, and thus their application is very limited. This is especially evident when collecting adhesive and wet FSPs or when purifying aggressive gas flows. New design multi-channel cyclone has a few principal elements of the structure such as secondary inlets, inner slits and convex bottom. These improvements allow to avoid an adhesion of sticky and moist SPs on the inner surfaces of the cyclone. This study focuses on estimating the effect of separating wood and wood ash SPs. The obtained results are presented and the comparison of the advantages and disadvantages of two different design multi-channel cyclone are provided.

The Experimental Study on the Principal Aerodynamic Characteristics and Their Influence on the Efficiency in a Cylindrical Two-Level Six-Channel Cyclone to Remove Dissimilar Types of Particles

The analysis of the two-level multi-channel cyclone operation requires the investigation of the treated air flow movement. The two-level multi-channel cyclone was designed for separating solid particles from the air flow and constructed at the Institute of the Environmental Protection of Vilnius Gediminas Technical University. The study was aimed at determining airflow distribution in a two-level six-channel cyclone and measuring air treatment efficiency. To determine the velocity of airflow in the channels, a multi-functional measuring instrument Testo-400 and the dynamic Pitot tube were used. The concentration of particles in the air inlet and outlet ducts was determined by the weight method. The obtained results showed that the same air volumes on both cyclone levels are equal and the velocity of the airflow was uniformly distributed in the channels. The maximum airflow velocity was recorded in the first channel. The mean airflow velocity in the channels did not differ significantly.

The investigation of the structure and operation of a multi-channel cyclone, separating fine solid particles from an aggressive dispersed gas and vapour flow

A multi-channel cyclone is a new-generation cleaning device, which purifies a gas flow by removing fine dispersion solid particles of 2 μm and larger in diameter from it. An aggressive dispersed gas flow can be formed under various conditions, for example, in combustion and processing of various products such as drying of chemical compounds, etc., at high temperature and/or high humidity. Multi-channel cyclones of a new generation have a number of advantages over the most widely used equipment for separating the particulate matter from the air flow such as electrostatic and bag filters, which are rather expensive, difficult to maintain and to be used for separating sticky and moist particles from the aggressive gas flow. The paper examines wood and lignin solid particles of different nature and properties present in a gas-vapour flow. Their adhesion and cohesion, depending on the time of the multi-channel cyclone operation aimed at purifying a dusted gas-vapour flow at high gas-vapour temperature and humidity are investigated. The research is aimed at determining the optimal separation efficiency and the aerodynamic parameters of a multi-channel cyclone and their variation by creating an aggressive dispersed gas flow. It assesses the detrimental effect of the deposition of wood and lignin solid particles on its interior surfaces, their cohesion and adhesion and clogging the system. The efficiency of the cyclone's operation is investigated for the flow, moving at medium rates and containing solid particles of various sizes. The highest cyclone's efficiency is determined for its separation of medium- and small-size solid particles. The theoretical study of kinematic and dynamic gas flow viscosity and the calculation of its coefficients as well as the dew point temperature of the flow are performed and the relationships between them are determined. The obtained results are presented and some recommendations for improving the structure of a multi-channel cyclone for separating sticky and moist particles from a humid and hot gas flow are provided.

Research of the Aerodynamic Parameters in a Special Cyclone with Secondary Inlets

Special cyclone – gas treatment device which can be applied to remove the fine particulate matter bigger than 2 micrometres from aggressive gas flow at a temperature of 50–145 °C and a relative humidity of more than 95% and can be achieved the cleaning efficiency over 90%. Cyclone work is based on centrifugal forces and the resulting additional filtration process operation. Cyclone structure equipped with primary and secondary gas flow inflows through which gas dispersed flow is supplied parallel to all channels of the cyclone. Analysed modified multi-channel cyclone can be effectively treated from fine particulate matter, during the cleaning of aggressive gas flow an adhesion/cohesion phenomena could be reduced. Research of aerodynamic parameters it’s the first step of studies to determine the optimal case, at the average gas flow velocity in cyclone channels were 8, 12 and 16 m/s, the gas flow dynamics dependencies into cyclone were determined.

Modelling trajectories of solid particle motion in the cyclone

PurposeThis purpose of the paper is to examine the multi-channel cyclone created at the Vilnius Gediminas Technical University (VGTU) Research Institute of Environmental Protection. The paper aims to predict the possible trajectories of solid particle motion in the cyclone with reference to the mechanical forces only.Design/methodology/approachThe numerical calculations were performed on the basis of experimental results. The system of differential equations describing particle motion in the cyclone is analysed and numerically solved using Runge–Kutta–Fehlberg method. Research consists of three examples that illustrate the impact of particle density and velocity on collection and analyses the particle motion trajectories in the first and second channels of the cyclone.FindingsNumerical calculations were performed according to the data from Vilnius Gediminas Technical University Research Institute of Environmental Protection. The particulate matter of wood ash and granite were used. The collection of solid particles of different size was examined when the air inflow velocity varies from 10 to 20 m/s. The possible motion trajectories of the solid particles are defined and the parameters of collected particles have been discussed.Research limitations/implicationsThe obtained results can be used for the analysis of air cleaning efficiency and particulate matter removal from air in a multi-channel cyclone.Practical implicationsThe results lead us to improve the structure of the cyclone so as to effectively collect the solid particles of different size.Originality/valueThis paper presents the results obtained for the multi-channel cyclone created at the Vilnius Gediminas Technical University Research Institute of Environmental Protection.

Research and Analysis of Aggressive Conditions Formation into a Multi Channel Cyclone

A multi channel cyclone is a new generation air treatment equipment that can remove fine stiff particles of up to 2 microns from air flow and reach the general effectiveness of 95%. The technological processes such as a combustion, products processing (drying, chemical compounds insertion) generate an aggressive conditions into polluted dusty gas flow. These processes change the physical, chemical and mechanical properties of fine particulate matter. The treatment plant and its working operation affects the emission of the compounds and their concentration, current water content of the gas stream (humidity) and temperature of the gas. This article is intended for analysis of special conditions formation in the air cleaning equipment and it is a first part of experimental research of aggressive conditions into a multi channel cyclone. The carried out research is aimed at establishing parameters of the gas-vapour flow in the cyclone under the increased humidity and temperature of the purified flow. The flow has been treated under simulation conditions in the laboratory used autoclave device, at the gas flow temperature of 20–150°C and gas flow humidity of 50–95%. Under an average flow velocity of 8, 12 and 16 m/s in the cyclone's channel.

Numerical simulation of the sticking process of glass-microparticles to a flat wall to represent pollutant-particles treatment in a multi-channel cyclone

Ultrafine particles are dangerous to human health and are usually difficult to separate from airflow because of their low inertia, which helps them to stick easily to surfaces because of adhesive forces. This characteristic provides opportunities for adhesive ultrafine particle separation by designing air-cleaning devices that exploit the sticking ability. To understand governing effects in such air-cleaning devices, which can be designed as multi-channel cyclones, the sticking of adhesive spherical glass particles under oblique impact has been investigated numerically by using the discrete element method. An adhesive dissipative contact model was applied by implementing different interaction forces for various-sized ultrafine pollutant particles. Normal loading is represented by the elastic Hertz contact model, whereas viscous damping is described by the modified nonlinear Tsuji model. The influence of deformation-dependent adhesive forces for a range of ultrafine particle sizes is illustrated during the sticking process. Dissipative oscillations during the sticking process were observed because of the influence of viscous damping forces.

Numerical study of the aerodynamic parameters in a two-level multichannel cyclone

ABSTRACTResearch has been designed to analyse changes in the aerodynamic parameters of the single-phase air flow in a multi-channel cylindrical cyclone for separation of particular matter from the flow, involving the task of numerical modelling for the tangential inlet cyclone. The research contains a review of numerical modelling works for cyclones, applicable models and equations for the complex description of turbulent flow. Differential equations are provided to reflect numerical solutions using the finite-volume method and k-ε turbulence model. The values obtained have been compared with the physical model of the given cyclone. The mean relative error for velocity values is ±8.1% and for aerodynamic resistance – 11.9%.

Investigation into a new generation multi-channel cyclone used for removing lignin particulate matter from gas under conditions of an aggressive environment

A multichannel cyclone is new generation air treatment equipment that can remove fine stiff particles of up to 2μm from air flow and reach the general effectiveness of 95%. The carried out research is aimed at establishing parameters for the dynamics of the gas–vapour two-phase flow in the cyclone and treatment efficiency removing stiff lignin particulate matter, i.e. under the increased humidity and temperature of the purified flow. The article describes the peculiarities of parameters for the cyclone—separator and analyses the results of the cyclones having different inner structures under conditions of an aggressive environment. The flow polluted with lignin particulate matter has been treated under simulation conditions in the laboratory, at the gas flow temperature of 28–30°C and gas flow humidity of 85–95%. Under an average vapour-PM flow velocity of 12m/s in the cyclone polluted with ultra-dispersive 20μm lignin particulate matter and conditions of the aggressive environment, treatment efficiency equals 82.5%.

EXPERIMENTAL RESEARCHES AND COMPARISON ON AERODYNAMIC PARAMETERS AND CLEANING EFFICIENCY OF MULTI-LEVEL MULTI-CHANNEL CYCLONE / DAUGIALYGIŲ DAUGIAKANALIŲ CIKLONŲ AERODINAMINIŲ PARAMETRŲ IR VALYMO EFEKTYVUMO EKSPERIMENTINIAI TYRIMAI IR PALYGINIMAS

Multi-level multi-channel cyclone – the lately designed air cleaning device that can remove ultra-fine 20 μm particulatematter (PM) from dusted air and reach over 95% of the overall cleaning efficiency. Multi-channel cyclone technology is based on centrifugal forces and has the resulting additional filtering process operation. Multi-level structure of cyclone allows to achieve higher air flow cleaning capacity at the same dimensions of the device, thus saving installation space required for the job, production and operating costs. Studies have examined the air flow parameters change in one–, two– and three–levels multichannel cyclone. These constructions differ according to the productivity of cleaned air under the constant peripheral and transitional (50/50 case) air flow relations. Accordance with the results of air flow dynamics – velocity distribution of multi-channel cyclone, aerodynamic resistance and efficiency can be judged on the flow turbulence, the flow channel cross-section and select the most appropriate application. Cleaning efficiency studies were carried out using fine granite and wood ashes PM. The maximum cleaning efficiency was 93.3%, at an average of 4.5 g/m3, the aerodynamic resistance was equal to 1525 Pa. Nagrinėjami daugialygiai daugiakanaliai ciklonai – naujos kartos oro valymo įrenginiai, galintys pašalinti iš užterštų oro srautų ypač smulkias kietąsias daleles nuo 2 mikronų dydžio bei pasiekti virš 95 % bendrą valymo efektyvumą. Daugiakanalių ciklonų darbas pagrįstas išcentrinių jėgų bei papildomai atsirandančio filtracijos proceso veikimu. Daugialygio ciklono konstrukcija leidžia pasiekti didesnio valomo oro srauto debitą, esant tiems patiems įrenginio matmenims, taip sutaupant įrenginio darbui reikalingą plotą, gamybos bei eksploatacines išlaidas. Atliktuose tyrimuose nagrinėjamas oro srauto parametrų kitimas vieno, dviejų ir trijų lygių daugiakanaliame ciklone, kintant valomo oro debitui, esant tolygiam 50/50 periferinio/tranzitinio oro srauto santykiui. Pagal gautą oro srauto dinamiką, greičių pasiskirstymą daugiakanalio ciklono kanaluose, nustatytą pasipriešinimą bei valymo efektyvumą galima spręsti apie srauto turbulentiškumą, srautų judėjimą kanalų skerspjūviuose ir parinkti tinkamiausią pritaikymą. Valymo efektyvumo tyrimai atlikti panaudojant granito bei medienos pelenų ypač smulkias kietąsias daleles. Didžiausias valymo efektyvumas siekė 93,3 %, esant vidutinei kietųjų dalelių 4,5 g/m3 koncentracijai, kai aerodinaminis pasipriešinimas buvo lygus 1525 Pa.

Optimization of the New Generation Multichannel Cyclone Cleaning Efficiency

Cyclone Dust Separators are devices often used to filter solid particles from flue gas. Such cyclones are supposed to filter as much particulate matter from the gaseous stream as possible. At the same time, they should only introduce minimal pressure loss to the system. Hence, collection efficiency has to be maximized and pressure loss minimized. Both the collection efficiency and pressure loss are heavily influenced by cyclone geometry. In this paper, we optimize inner geometrical construction of multichannel cyclone to up cleaning efficiency parameter. This study shows how geometry involves cleaning efficiency. At air flow rates from 12 m/s to 18 m/s after researches the optimal cleaning efficiency achieved in the three level cyclone at 16 m/s average air flow rate in cyclone channels, when the treated air is polluted with 20 μm size granite particles and flow distribution ratio is 75/25. For low density particles (wood ash) for the 20 μm diameter top efficiency established in 6-channel cyclone at the 16 m/s air flow rate in the channels and flow distribution ratio 75/25.

DEM Simulation of the Impact of Ultrafine Glass Particles on the Partition Wall of the Multichannel Cyclone

This article focuses on the simulation of the impact of ultrafine particles on the rigid partition wall of the multichannel cyclone by applying the discrete element method (DEM). Ultrafine particles with diameters ranging from 0.1 to 10 µm are assumed to be most dangerous pollutants because of their property to easily penetrate the human circulatory system through the respiratory tract. An emphasis is placed on demonstrating the stick-rebound behavior of glass pollutant particles. The numerical experiment simulating the oblique impact load induced by mechanically generated inlet air flow has been numerically conducted. Hertz contact and short-range van der Waals attraction are the main forces describing normal contact, while their tangential counterpart is defined according to Coulomb friction law and by considering normal compression and attraction. Both normal and tangential models are modified to comprise the effect of energy dissipation due to adhesion hysteresis. Simulation results provide a theoretical framework for designing of the cyclone when a device is applied to capture ultrafine pollutant particles.

EXPERIMENTAL RESEARCH INTO THE TWO-LEVEL CYLINDRICAL CYCLONE WITH A DIFFERENT NUMBER OF CHANNELS / DVIEJŲ LYGIŲ CILINDRINIO CIKLONO SU SKIRTINGU KANALŲ SKAIČIUMI EKSPERIMENTINIAI TYRIMAI

The multichannel two-level cyclone has been designed for separating solid particles from airflow and built at the Laboratory of Environmental Protection Technologies of Vilnius Gediminas Technical University. The conducted research is aimed at determining air flow distribution at two levels and channels of the multichannel cyclone. The multifunctional meter Testo-400 and the dynamic Pitot tube have been used form easuring air flow rates in the channels. The obtained results show that the equal volume of air gets into two levels installed inside the cyclone, and rates are distributed equally in the channels of these levels. The maximum air flow rate is recorded in the first channel and occurs when half-rings are set in such positions so that 75% of air flow returns to the previous channel. The biggest aerodynamic resistance is 1660 Pa and has been recorded in the cyclone having eight channels under air flow distribution ratio 75/25. The highest air purification efficiency has been observed in the two-level six-channel cyclone under air flow distribution ratio 75/25. The effectiveness of separating granite particles is 92.1% and that of wood particles – 91.1 when the particles are up to 20 μm in diameter. Dviejų lygių daugiakanalis ciklonas skirtas kietosioms dalelėms iš oro srauto atskirti. Toks ciklonas sukurtas Vilniaus Gedimino technikos universiteto Aplinkos apsaugos laboratorijoje. Tyrimais siekiama nustatyti oro srauto pasiskirstymą daugiakanalio ciklono lygiuose ir kanaluose. Oro greičiams kanaluose nustatyti naudojamas daugiafunkcis matuoklis „Testo-400“ ir dinaminis Pito vamzdelis. Gauti rezultatai parodė, kad į ciklone įrengtus lygius patenka vienodas oro tūris, ir greičiai šių lygių kanaluose pasiskirsto vienodai. Didžiausias greitis užfiksuotas pirmajame kanale. Didžiausias yra tuo atveju, kai pusžiedžiai sudėti taip, jog 75 % oro srauto grįžtų į ankstesnį kanalą, o mažiausias tada, kai į ankstesnį kanalą grįžta 25 % oro srauto. Didžiausias išmatuotas aerodinaminis pasipriešinimas yra esant aštuoniems kanalams bei 75/25 oro srautų pasiskirstymo santykiui ir siekia 1660 Pa. Ištyrus ciklono su skirtingu kanalų skaičiumi efektyvumą nustatyta, kad geriausiai daleles iš oro atskiria šešiakanalis ciklonas, kuriame oro srautų pasiskirstymo santykis yra 75/25. Granito dalelių iki 20 μm atskyrimo 92,1 %, o medienos dalelių – 91,1 %.

RESEARCH INTO THE CLEANING EFFICIENCY OF 300 M3/H MAINTAINED BY THE SPIRAL MULTI-CHANNEL CYCLONE IN THE PROCESS OF REMOVING SOLID PARTICLES OF <20 ΜM / 300 M3/H NAŠUMO SPIRALINIO DAUGIAKANALIO CIKLONO VALYMO EFEKTYVUMO TYRIMAS, ŠALINANT < 20 ΜM KIETĄSIAS

Tests on the cleaning efficiency of an experimental spiral cyclone have been conducted to determine the removal efficiency of the solid particles the dispersion of which makes <20 µm in the streamlined multi-channel cyclone. The introduced device is adapted to removing ultrafine particulate matter from contaminated air (gas) flow. A multi-channel cyclone with spiral casing has been designed at the Department of Environmental Protection (DEP) of Vilnius Gediminas Technical University. Experimental studies have disclosed that air (gas) flow cleaning efficiency of the spiral multi-cyclone (capacity 300 m3) depend on the internal structure of the device, i.e. on the number of channels and air (gas) flow distribution ratio of transit and peripheral channels. Also, the treatment efficiency of the applied equipment has been evaluated removing solid particles of different nature. AFA-VP-20 filters have been employed for conducting experimental tests. The obtained results have disclosed that solid granite particles – 95.1%, glass – 91.4% and wood – 92.2% are removed most effectively. Eksperimentiniai spiralinio ciklono valymo efektyvumo tyrimai atliekami siekiant nustatyti kietųjų dalelių, kurių dispersija x < 20 μm, pašalinimo efektyvumą patobulintame daugiakanaliame ciklone. Minėtas įrenginys pritaikytas itin smulkioms kietosioms dalelėms iš užteršto oro (dujų) srauto pašalinti. Daugiakanalis ciklonas, turintis spiralinį korpusą, sukurtas Vilniaus Gedimino technikos universiteto (VGTU) Aplinkos apsaugos katedroje (AAK). Eksperimentinių tyrimų metu nustatytas spiralinio daugiakanalio ciklono (našumas 300 m3/h) oro (dujų) srauto valymo efektyvumas priklausomai nuo vidinės įrenginio konstrukcijos, t. y. nuo kanalų skaičiaus ir oro (dujų) srauto pasiskirstymo į tranzitinį ir periferinį kanalus santykio. Taip pat įvertintas įrenginio valymo efektyvumas, šalinant skirtingos prigimties kietąsias daleles. Eksperimentiniams bandymams atlikti naudoti AFA-VP-20 filtrai. Remiantis bandymų rezultatais, nustatyta, kad efektyviausiai šalinamos granito kietosios dalelės – 95,1 %, stiklas – 91,4 %, mediena – 92,2 %.

AIR STREAM VELOCITY MODELLING IN MULTICHANNEL SPIRAL CYCLONE SEPARATOR

Numerical modelling problem is investigated in a gas aerodynamics multichannel spiral cyclone separator with a tangential inflow. Experimental and theoretical papers analysing cyclone separator with particularly complex turbulent flow were reviewed. The three-dimensional transport differential equations for incompressible laminar and turbulent flow inside the cyclone separator were presented. They were numerically solved by finite volume method using the Re-Normalisation Group (hereinafter RNG) k-ε turbulence model. The numerical air flow movement was modelled in cyclone separator with the following dimensions: 0.95 m height, 0.330 m diameter, 0.88 m height of spiral-cylindrical part, 0.39 m height of conical part, inflow dimensions (on the side of cylindrical part) according to the drawings were a × b = 28 × 95 mm. The mathematical model of air flow movement in cyclone separator was composed by Navier-Stokes (Reynolds) as the three-dimensional differential equation system. The modelling results were obtained by the tangential and axial velocity profiles in cyclone separator using RNG k-ε turbulence model, the inflow velocity from 4.1 m/s to 15.4 m/s coincided well with the experimental results. This is the first article testing for multichannel cyclone and determined distributions of aerodynamic parameters. The absolute error between experimental and modelling results changed from 0.01 to 0.24 units.

MATHEMATICAL MODEL OF THE MULTI-CHANNEL SPIRAL CYCLONE / DAUGIAKANALIO SPIRALINIO CIKLONO ORO GREIČIŲ TYRIMAS

The article deals with a problem of experimental investigation and numerical simulation of gas aerodynamics of a multi-channel spiral cyclone with a tangential inlet. The paper presents an overview of experimental and theoretical works on the cyclones having a particularly complex turbulent flow and focuses on three-dimensional transport differential equations for a non-compressible laminar and turbulent flow inside the cyclone. The equations have been solved applying the numerical finite volume method using the RNG (Re–Normalisation Group) k-ε turbulence model. The numerical simulation of the flow cyclone has been carried out. The height of the cyclone is 0.80 m with 0.33 m in diameter, the height of the spiral–cylindrical part – 0.098 meters and that of the cone – 0.45 m. Inlet dimensions (cylindrical part on the side), in accordance with drawings makes a×b = 28×95 mm. The mathematical model for the air traffic movement cyclone has accounted for Navier-Stokes (Reynolds) three-dimensional differential equations. The simulation results have been obtained with reference to the cyclone of tangential velocity profiles using RNG k-ε turbulence model. The inlet velocity of 5.1 m/s slightly differs from experimental results, thus making an error of 7%. Article in Lithuanian. Santrauka Nagrinėjama dujų aerodinamikos daugiakanaliame spiraliniame ciklone eksperimentinio tyrimo ir skaitinio modeliavimo problema. Apžvelgti eksperimentiniai ir teoriniai ciklonų, kuriuose susidaro ypač sudėtingas sūkurinis srautas, tyrimai. Pateiktos nespūdžiojo laminarinio ir turbulentinio srauto tekėjimo ciklono viduje diferencialinės trimatės pernašos lygtys. Jos skaitiškai spręstos baigtinių tūrių metodu taikant RNG (Re – Normalisation Group) k–ε turbulencijos modelį. Atliktas skaitinis oro srauto judėjimo ciklone modeliavimas. Ciklono aukštis 0,80 m, skersmuo 0,33 m, spiralinės-cilindrinės dalies aukštis 0,098 m, kūginės – 0,45 m, įtekėjimo angos matmenys (cilindrinės dalies šone) pagal brėžinius yra a×b = 28×95 mm. Oro srauto judėjimo ciklone matematinį modelį sudaro Navjė ir Stokso (Reinoldso) trimačių diferencialinių lygčių sistema. Modeliavimo rezultatai, t. y. taikant RNG k–ε turbulencijos modelį (įtekėjimo greitis 5,1 m/s) gauti tangentinio greičio ciklone kitimo duomenys, nežymiai (su 7 % paklaida) skyrėsi nuo eksperimentinių rezultatų.