Numeric Simulation of Gas-Dynamic Processes in the Swirl Combustion Chamber in STAR-CCM+

2012 ◽  
Vol 241-244 ◽  
pp. 1271-1277
Author(s):  
Igor Kuksov ◽  
Sergey Mochalov ◽  
Vladimir Sarychev

The paper examines the theoretical and practical aspects of modeling of gas-dynamic processes in the swirl chamber. The results of numerical computation of a swirling gas flow induced by two-row header in cylindrical chamber are presented. The description of two-phase flow model subject to the injection of particles is given. It is revealed that in stationary mode two characteristic zones are formed: axial zone of quasi-solid rotation and cylinder surface zone.

2003 ◽  
Vol 44 (3) ◽  
pp. 312-316
Author(s):  
I. M. Vasenin1 ◽  
T. V. Vasenina2 ◽  
A. A. Glazunov2

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1745
Author(s):  
Marek Ochowiak ◽  
Daniel Janecki ◽  
Andżelika Krupińska ◽  
Sylwia Włodarczak ◽  
Tomasz Wilk ◽  
...  

This paper presents the results of numerical simulations for the developed and discussed conical two-phase atomizers with swirl flow, differing in the ratio of the height of the swirl chamber to its diameter. Experiments were carried out for SAN-1 with HS/DS = 1 and SAN-2 with HS/DS = 4 atomizers. The study was conducted over a range of Reynolds number for liquid ReL = (1400; 5650) and for gas ReG = (2970; 9900). Numerical calculations were performed with the use of computational fluid dynamics (CFD), which were verified on the basis of experimental data. Based on the analysis of experimental studies and simulations results the influence of operational parameters and changes of the atomizer geometry on the generated spray was demonstrated. As the gas flow rate increased and the swirl chamber height decreased, the spray angle increased. Higher velocity values of the liquid and greater turbulence occur in the center of the spray. The flow inside the atomizer determines the nature of the spray obtained. The geometry of the swirl chamber influences the air core formed inside the atomizer, and this determines the atomization effect. The results of numerical simulations not only confirm the results of experimental studies, but also provide additional information on internal and external fluid flow.


Author(s):  
G. O. Voropaiev ◽  
Ia. V. Zagumennyi ◽  
N. V. Rozumnyuk

The paper presents the numerical results on gas-dynamic processes in various elements of the impulse ejector, including pre-chamber, supersonic nozzle and mixing chamber, to determine optimal geometric parameters providing the given flow rate characteristics. At an extra-high pressure of the ejecting gas (>100 bar) it is impossible to create a nozzle design with continuously changing cross-sectional area and limited nozzle length. So, it is necessary to place a pre-chamber between the gas generator and the ejector nozzle for throttling full gas pressure. In order to optimize the pre-chamber parameters in the ejector with discrete holes of the gas generator and the operating pressure in the range of 400÷1000 bar, a series of calculations were performed to determine the pre-chamber parameters, ensuring stable operation of the supersonic annular nozzle at the high pressure of 35÷45 bar and the flow rate of 0.5÷0.6 kg/s. 3D numerical simulation of the gas flow into the pre-chamber through the gas generator holes shows the degree of the flow pattern non-uniformity in the pre-chamber at the ejector nozzle inlet is quite low. This justifies the numerical simulation of gas flow in the ejector in axisymmetric formulation and allows restricting the number of the gas generator holes without inducing significant non-uniformity in the azimuthal direction.


2021 ◽  
Vol 11 (23) ◽  
pp. 11146
Author(s):  
Aleksandr Minko ◽  
Oleg Guskov ◽  
Konstantin Arefyev ◽  
Andrey Saveliev

Present work is devoted to physical and mathematical modeling of the secondary disintegration of a liquid jet and gas-dynamic breakup of droplets in high-speed air flows. In this work the analysis of the experiments of water droplet breakup in the supersonic flow with Mach numbers up to M = 3 was carried out. The influence of shock wave presence in the flow on the intensity of droplets gas-dynamic breakup is shown. A developed empirical model is presented. It allows to predict the distribution of droplet diameters and velocities depending on the gas flow conditions, as well as the physical properties of the liquid. The effect of the Weber and Reynolds numbers on the rate of droplets gas-dynamic breakup at various Mach numbers is shown. The obtained data can be useful in the development of mathematical models for the numerical simulation of two-phase flows in the combined Lagrange-Euler formulation.


Author(s):  
V.B. Volovetskyi ◽  
Ya. Doroshenko ◽  
G. Kogut ◽  
A.P. Dzhus ◽  
I.V. Rybitskyi ◽  
...  

Purpose: The article implies theoretical and experimental studies of the liquid pollution accumulations impact on the efficiency of gathering gas pipelines operation at the Yuliivskyi oil and gas condensate production facility (OGCPF). Research of efficiency of gas pipelines cleaning by various methods. Design/methodology/approach: The research methodology consists of determining the hydraulic efficiency of gathering gas pipelines before and after cleaning of their internal cavity by different methods and comparing the obtained results, which allows to objectively evaluate the efficiency of any cleaning method. CFD simulation of gas-dynamic processes in low sections of gas pipelines with liquid contaminants. Findings: Experimental studies of cleaning efficiency in the inner cavity of the gas gathering pipelines of the Yuliivskyi OGCPF by various methods, including: supply of surfactant solution, creating a high-speed gas flow, use of foam pistons were performed. It was established that cleaning the inner cavity of gas gathering pipelines by supplying a surfactant solution leads to an increase in the coefficient of hydraulic efficiency by 2%-4.5%, creating a high-speed gas flow by 4%-7%, and under certain conditions by 8%-10 % and more. However, for two gas pipelines the use of foam pistons allowed to increase the coefficient of hydraulic efficiency from 5.7 % to 10.5 % with a multiplicity of foam from 50 to 90. be recommended for other deposits.The results of CFD simulation showed that the accumulation of liquid contaminants in the lowered sections of gas pipelines affects gas-dynamic processes and leads to pressure losses above the values provided by the technological regime. With the increase in liquid contaminants volume the pressure losses occur. Moreover, with a small amount of contamination (up to 0.006 m3), liquid contaminants do not have a significant effect on pressure loss. If the contaminants volume in the lowered section of the pipeline is greater than the specified value, the pressure loss increases by parabolic dependence. The increase in mass flow leads to an increase in the value of pressure loss at the site of liquid contamination. Moreover, the greater the mass flow, the greater the impact of its changes on the pressure loss. The CFD simulation performed made it possible not only to determine the patterns of pressure loss in places of liquid contaminants accumulation in the inner cavity of gas pipelines, but also to understand the gas-dynamic processes in such places, which is an unconditional advantage of this method over experimental. Research limitations/implications: The obtained simulation results showed that the increase in the volume of liquid contaminants in the inner cavity of gas gathering pipelines leads to an increase in pressure losses above the value provided by the technological regime. To achieve maximum cleaning of gas gathering pipelines, it is necessary to develop a new method that will combine the considered. Practical implications: The performed experimental results make it possible to take a more thorough approach to cleaning the inner cavity of gas gathering pipelines and to forecast in advance to what extent the hydraulic efficiency of gas gathering pipelines can be increased. Originality/value: The obtained results of CFD simulation of gas-dynamic processes in lowered sections of gas pipelines with liquid contaminants, experimental studies of the effectiveness of various methods of cleaning the inner cavity of gas gathering pipelines has original value.


2018 ◽  
pp. 57-61
Author(s):  
Y Karakash ◽  
L Gres ◽  
O Gupalo

The article deals with the methods of physical modeling of gas-dynamic processes and the calculation of aerodynamic resistance in the motion of combustion products on the exhaust system. The analysis of echoing methods for increasing the diversion of combustion products of hot stoves has been carried out and their main disadvantages have been identified. The basic principles of creation of mathematical models of flue gas flow on an exhaust system are considered and an estimation of their adaptability to the really conditions. The main reasons for the reduction of traction in the exhaust system of the blast-furnace shop of Dneprovsky DMZ are revealed. The research of the state of refractory lining was conducted and the main reasons of a short period of its work were revealed. The ejection and injection phenomena on the basis of which several ways of increasing traction in the chimney tract are considered. Investigations of the level of pressure of combustion products at the exit from the combustion chamber on the existing air heaters have been carried out. The influence of taking blast furnace on draft through air heaters on the duration of service life of refractories of exhaust system and the degree of mixing of combustion products during tangential feeding to common forests is revealed. The calculation of pressure losses in the smoke boron under the conditions of the blast-furnace shop of Dneprovsky DMZ is carried out. Considered ways to increase the value of traction for effective smoke removal from blast air heaters. During the experiments, the distribution of flows between the ejector and around the nozzle was detected. Conclusions are made on the necessity of using some methods for increasing traction in smoke boron and the correspondence of some coefficients of local resistance to experimental data. It is suggested to conduct further physical experiments to specify the coefficients of local resistance.


2003 ◽  
Vol 3 ◽  
pp. 266-270
Author(s):  
B.H. Khudjuyerov ◽  
I.A. Chuliev

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.


1986 ◽  
Vol 51 (5) ◽  
pp. 1001-1015 ◽  
Author(s):  
Ivan Fořt ◽  
Vladimír Rogalewicz ◽  
Miroslav Richter

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.


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