FlowVision Software Research Articles

Mathematical modeling of the melt flow in the cone-ring channel of the extruder matrix

The peculiarity of the work is to develop a mathematical model of the melt flow in the cone-annular channel of the extruder die, which will allow you to choose the optimal geometric shape of the annular channel, as well as the angular rotation speed of the extruder screw. The object of the study is the cone-ring channel of the extruder matrix. To solve the three-dimensional problem of turbulent and laminar unsteady motion, the FlowVision software package was used, which allows solving partial differential equations using the finite volume method. The correct choice of the geometric shape of the annular gap made it possible to change the molecular structure of the product by creating a maximum pressure value. The optimally selected angular rotation speed of the extruder screw made it possible to carry out deep melting of the product due to the conversion of the mechanical energy of the screw into thermal energy. In the process of designing the forming of the cone-ring channel, the three volumes of the changing geometry of the stamp were selected, at the borders of the transition of which extreme points were observed. Deviations between the analyzed and experimental values of velocity and pressure were found in the limits of 9–12 % and 17–22 %, respectively. Based on the analysis of the obtained results of modeling, the optimal geometric shape of the annular gap and the recommended angular rotation speed of the extruder screw were revealed. The mathematical model proposed formed the basis of the developed design of the six-zone extruder. In the extruder, the geometric characteristics of the screw (variable pitch of the turns) were substantiated and selected, which provide the maximum effect of dissipation, i.e. autogenous mode of operation

Analysis of the Hydrodynamics of Swirling Flows in Direct-Flow Cyclones

A mathematical model is presented that describes the movement of gas in a direct-flow cyclone. The equations of motion of the gas phase were solved and profiles for the tangential and axial components of gas velocity were derived based on them. The results obtained are compared with the results of numerical simulation. The latter was carried out in the FlowVision software using the SST turbulence model. Via numerical calculations the change in the tangential and axial components of the gas velocity was determined at distances of 110, 150, 200, and 250 mm from the plate turbulator, or cyclone swirler.

Моделирование турбулентных сжимаемых течений в программном комплексе FlowVision

Моделирование турбулентных сжимаемых течений в программном комплексе FlowVision

Численное моделирование течения жидкости в насосе для перекачки крови в программном комплексе FlowVision

Численное моделирование течения жидкости в насосе для перекачки крови в программном комплексе FlowVision

Моделирование LES-подходом в ПК FlowVision турбулентного перемешивания разнотемпературных потоков в T-образном трубопроводе

Моделирование LES-подходом в ПК FlowVision турбулентного перемешивания разнотемпературных потоков в T-образном трубопроводе

Опыт использования отечественного программного комплекса FlowVision в МГТУ им. Н.Э. Баумана

The paper considers examples of Russian software package FlowVision application for solving aircraft aerodynamics and flow control problems at Bauman Moscow State Technical University. Numerical modeling was carried out using various approaches, such as solving purely aerodynamic problems of flow around various bodies using Reynolds-averaged Navier-Stokes equations supplemented by a turbulence model, as well as coupled problems of aerodynamics and motion dynamics. Young scientists, postgraduate students and students of Bauman Moscow State Technical University were involved in the research. The problems of determining interference and rotation influence on the aerodynamics and dynamics of aircraft detachable structural elements, as well as aircraft flow control using perforated surfaces, are considered. The advantages and difficulties in working with the software package are revealed when solving the problems. The pluses of FlowVision are the ability to solve conjugate problems and problems on moving grids. The most important advantage of the FlowVision software product is the possibility of direct contact with developers, which allows not only to quickly resolve user issues, but also improve the convenience and functionality of the package.

Валидационные расчеты задач гемодинамики с использованием программного комплекса FlowVision в режиме распараллеливания

Проведены расчеты тестовой задачи, связанной с моделированием течения в идеализированном медицинском устройстве, в программном комплексе FlowVision. Расчеты проводились для ламинарного, турбулентного и переходного режимов течения. Исследована масштабируемость задачи. На основе решения тестовой задачи сделан вывод о возможности применения программного комплекса FlowVision к решению проблем гемодинамики. The calculations of the test problem associated with the simulation of the flow in an idealized medical device were carried out in the FlowVision software package. The calculations were carried out for laminar, turbulent and transitional flow regimes. The scalability of the problem is studied. Based on the solution of the test problem, a conclusion was made about the possibility of using the FlowVision software package to solve hemodynamic problems.

RESEARCH OF THE AERODYNAMIC PROCESS OF CARBON DUST REMOVAL FROM THE WORKING ZONE

The purpose of this work is research of the aerodynamic process of carbon dust removal from the working zone in order to create safe and harmless working conditions at the production site. As a result of the research, an aerodynamic calculation of a long air duct of uniform suction with tangential air intake was performed. The degree of twisting of the air flow inside the air duct, as well as the uniformity of air suction along the length of the long suction, were determined. A number of factors affecting the dust removal process have been established, such as suction torch long suction; coefficient of local suction resistance; forces of inertia and viscosity on the resistance of local suction. The dependence of the ratio of the width of the entrance hole to the diameter of the air duct on the local suction resistance, the dependence of the ratio of the areas of the entrance gap and the cross section of the transitional air duct on the local suction resistance, as well as the effect of the length of the entrance slot on the coefficient of local suction resistance were determined. The efficiency of suction of dust particles with an extended suction unit with tangential air entry has been proven. For a more accurate analysis of the distance at which an extended extractor with tangential air intake can be placed relative to the dust source, it is necessary to conduct a dispersed dust analysis. For effective capture of specific dust, calculations should be based on the size of the dust, which occupies a larger share in the distribution of fractions. The smaller the dust particle, the further the suction device can be located. To visualize the experimentally obtained results, simulation was performed in the FlowVision software in accordance with the mathematically calculated initial data. During the simulation of the movement of dusty air in an extended extractor with a tangential entry into the system, the occurrence of swirling of the air flow has been proven. Due to this formation, the largest fractions of dust will move along the walls of the air duct. This makes it possible to use extended extractors to remove coarse fractions of dust contained in polluted air, organizing the removal of air moving near the walls of the air duct. Keywords: carbon dust, aerodynamic calculation, engineering simulation, occupational diseases, occupational health.

Development of a model of atmospheric aerothermodynamics for the study of dusting processes at tailings dumps using COMSOL software

An overview of studies of aerothermodynamics and atmospheric pollution at mining facilities using computational fluid dynamics software systems (CFD modeling) has been presented. Both specialized and non-specialized software are marked. The review focuses on the studies performed using the FLOWVISION, ANSYS FLUENT and COMSOL software codes. An aerothermodynamic model of the atmosphere is described in which the equations of dynamics in the incompressible fluid approximation are supplemented by the heat transfer equation and the parameters of Coriolis, convection (buoyancy), background stratification and radiation flux. The necessary modifications in the COMSOL software are described, which make it possible to carry out studies of atmospheric aerothermodynamics under various atmospheric conditions. A two-dimensional CFD model of the atmosphere has been built and tested on a simplified representation of the tailings dump. At a fixed wind flow velocity of 5 m/s and variations in the background stratification parameter (from –0.05 to +0.05 °C/m), numerical experiments have been performed and the calculation results have been analyzed. Differences in the aerodynamic parameters of the flows and the spatial distribution of temperature under different atmospheric conditions are noted. Estimates of the dynamic velocity at the dusting height and the vertical mass flux using the empirical dependence of the dusting intensity are performed. The analytical dependence of the vertical mass flux as a function of the stratification parameter is discussed. The asymmetry (relative to the neutral state of the atmosphere) of the magnitude of the vertical mass flux in comparison with the unstable and inversion states is shown. In stable atmospheric conditions, the magnitude of the vertical flux of the dust mass, and hence the pollution of the atmosphere downstream, will be noticeably higher than in unstable states.

Hydrodynamics of Energy-Efficient Axial-Flow Cyclones for Environmentally Safe Cleaning of Gas and Dust Emissions

We investigated the operation of an axial-flow cyclone as the most promising dust-cleaning equipment based on energy consumption. Numerical solutions were obtained for the gas-solids suspension flow equations in axial flow cyclones with different separation chambers’ geometry using FlowVision software. The chamber’s geometrical features determined the nature of the gas-solids suspension flow, directly affecting the dusty gases’ purification degree. The circulating gas flows and the turbulent “trace” after the swirl generator were found to negatively influence the cyclone efficiency and the hydraulic resistance values. A high chamber height also negatively affected the gas purification since the bulk of dust particles were removed from the gas-solids flow at the initial section. The initial section’s length coincided with the gas-solids suspension’s jet flow zone due to the flow coming off the swirl vanes’ edges. Due to turbulent mixing, the particles’ secondary entrainment and return to the gas flow began to manifest outside this zone. Based on this analysis, it is possible to develop recommendations for choosing the chamber’s geometric parameters, minimizing the influence of the indicated factors. On the basis of this research, it will be possible to ensure cyclones’ high efficiency with significantly lower hydraulic resistance when designing axial-flow cyclones relative to other types of cyclone.

МОДЕЛИРОВАНИЕ АЭРОДИНАМИЧЕСКОГО ВЗАИМОДЕЙСТВИЯ ПРИ ТРЕКОВЫХ ИСПЫТАНИЯХ ИЗДЕЛИЙ АВИАЦИОННОЙ ТЕХНИКИ

Ground track tests of modern ballistic-type aircraft products make it possible to simulate aerodynamic loads in conditions with a maximum medium density and having a significantly lower cost compared to flight tests. During track testing of products at supersonic speeds, intense vibrations of the structural elements of the movable track equipment and the product under test occur. The article deals with the processes of air flow around a rail installation moving with a high acceleration. Basic models are applied that describe the motion of a homogeneous medium at various velocities, accounting the effects of compressibility, turbulence, and heat transfer. Depending on the conditions, various flow turbulence models are used. An algorithm for numerical implementation on a rectangular grid with local adaptation and subgrid resolution of complex geometry is developed. The methodology for the numerical solution of the equations of dynamics describing the flow of a compressible gas around a curved surface is based on the integration of fluid motion and the transfer of scalar quantities in partial derivatives with respect to the volumes of computational cells-polyhedrons. Using the FlowVision software package, the simulation of the supersonic air flow around products of various shapes was performed in relation to track tests. This made it possible to determine previously unknown dependences of the coefficients of aerodynamic drag, lift force and lateral force on the speed of motion, as well as the moments of aerodynamic forces for estimating the contribution of airflow processes to the total vibration field acting on the track carriage with the product.

To the Theory of Grain Motion in an Uneven Air Flow in a Vertical Pneumatic Separation Channel with an Annular Cross Section

The possibilities of the action of uneven air flows on the grain material in the separating channels are still not used enough. The reason for this is the insufficient knowledge of the processes of interaction of the components of the grain material with an uneven air flow. The purpose of the research is to increase the efficiency of grain material separation according to aerodynamic properties by purposefully changing the diagram of air velocities in the channel sections using the actions of lateral and aerodynamic forces. The separation efficiency of grain material components was determined by trajectory analysis. The different geometry of the pneumatic separation channel was studied. The study of the distribution of air velocity and air pressure vectors in a vertical annular channel was carried out using the FlowVision software. It has been established that a change in the air velocity diagram can be implemented both by changing the geometric parameters of the channel and by additional distributed air supply through the perforation in the side walls of the pneumatic channel. Based on the analysis of the velocity field, an improved scheme of a pneumatic gravitational separator is proposed for separating grain material into three fractions according to aerodynamic characteristics.

Modeling of pollution propagation processes during dry cargo ship accidents

Pollution occurring with dry cargo ships can be accompanied by serious environmental consequences. At the same time, the object of the analysis was accidents with dry cargo ships carrying technical salt. Their consequences may be associated with the dissolution of salt in a river reservoir, the formation of impurities and their interaction with background pollutants. As a consequence, this can lead to increased corrosion of water intake structures, an increase in possible environmental losses. This work is a continuation of the authors' work related to the spread of pollution from transport accidents on inland waterways, assessment of the environmental risk of such accidents. All this suggests the need to model the processes of the spread of pollutants in predicting the consequences of such accidents. In this work, a site was selected in the area of 911 -913 km of the Volga River. Modeling was carried out using the FlowVision software package. The article shows the stages of the simulation of the pollution propagation process taking into account the speed of the river flow, the diameter of the pollution particles and chemical reactions occurring when the cargo enters the water. The areas of concentration of pollution deposits have been identified, which will allow in the future to propose an optimal scheme of the site for improving its ecology, as well as to clarify the methodology of predicted environmental damage

Numerical Simulation of Gas Flow Passing through Slots of Various Shapes in Labyrinth Seals

Labyrinth seals are widely used in centrifugal compressors, turbines, and many other pneumatic systems due to their simplicity of design, reliability, and low cost. The calculation scheme for the movement of the working medium in a labyrinth seal is constructed by analogy with the movement of the working medium through holes with a sharp edge. Annular and flat slots, holes, and such a factor as the shaft rotation with a calculated sector of 3 degrees were studied. The purpose of the study is to determine the flow coefficient when the working medium flows through slots of various shapes. To achieve this purpose, modeling of the working medium flow in the FlowVision software was performed. The mass flow and flow coefficients are determined for the studied slot shapes. The convergence of the calculation results was determined by comparing the values of the mass flow rate at the inlet and outlet of the slot. Differences in visualizations of the flow for the studied variants of slots were established. The resulting difference should be taken into account in practical calculations of the working medium mass flow through the slot using a conditional flow rate factor which is determined by the slot design.

Development of the optical electronic setup for carrying out measurements by multicolor Particle Image Velocimetry

The paper is devoted to development of the optical electronic setup for carrying out measurements by multicolor particle image velocimetry. The main advantage of this method is the ability to visualize vector velocity fields in several planes simultaneously. As a result a 3D model of a setup was developed, a laboratory sample was assembled and series of testing experiments were performed. As a test object, vortex structure formed by a chemical stirrer in a cuvette with liquid has been considered. The experimental data were compared with the computer model developed in SolidWorks and FlowVision software.

Численное исследование аэродинамических характеристик возвращаемого аппарата и донного элемента конструкции в процессе их разделения

The paper considers the effect that the separating process of a parachute container hatch door (PCHD) in the base of a reentry vehicle has on their aerodynamic characteristics. The FlowVision software package was used for flow simulation. With the help of a dynamic mesh, the trajectories of the PCHD movement were obtained without taking into account the gravity. The aerodynamic characteristics of the reentry vehicle and PCHD (in motion) were determined. The cases in which the PCHD and reentry vehicle may collide were identified. For these cases, a pulse analysis was carried out and the minimum initial velocity for the safe separation of the PCHD was determined.

Simulation of a three-dimensional model of the intake system of an agricultural tractor engine

The paper defines the nature and parameters of the air flow after passing the throttle valve. This research problem was solved mathematically using a software package for modeling gas-hydraulic processes. The simulation was carried out using the FlowVision software package. For this purpose, using various standard file formats, the geometry was obtained and imported, which is understood as a three-dimensional model of the internal volumes of the engine-intake and exhaust pipelines, the over-piston volume of the cylinder, etc. This allows you to use the SolidWorks computer-aided design system to create a computational domain. For the area of calculation, the volume was adopted, in which the equations of the mathematical model and the volume boundary with the definition of boundary conditions were determined. The resulting geometry is saved in the format supported by FlowVision and used when creating a new calculation variant.

Improvement of aerodynamic characteristics of air propellers of wind power plants using jet mechanization of blades

The paper considers the possibility of increasing the efficiency of wind power plants through the use of jet mechanization of propeller blades. The study of jet mechanization of the blade was carried out for the aerodynamic profile of NACA 0012 by numerical simulation in the Flow Vision software. The calculations were carried out by solving the plane problem of a completely compressible fluid or gas flow around the blade profile. The results of numerical simulation confirmed the change in the profile characteristics when additional air is supplied to the profile suction surface. The results obtained have been verified with the results of other authors. The data obtained as a result of modeling can be used both in the creation of new wind stations and in the capital improvement of the existing ones.

Methane combustion kinetic schemes in FlowVision software

The two-step chain reaction of methane combustion in air is integrated into the FlowVision software package. The conical flame numerical simulation under normal conditions using the built-in single-step chemical reaction was performed. A comparative analysis of the numerical results for one- and two-step schemes, as well as experimental results was made.

Numerical analysis of the influence of the front heat shield separation process from the descent module on their aerodynamic characteristics

This paper considers aerodynamic characteristics of the descent module and the separable front heat shield (FHS) during its separation. FlowVision software was used to perform a numerical analysis of the flow around the front heat shield and descent module. The calculations were performed using dynamic and static meshes. The trajectory of the front heat shield after separation was calculated using dynamic mesh. The aerodynamic characteristics of the frontal heat shield in several positions on calculated trajectory were determined using static mesh. The results of the calculations using different kind of grids are compared.