scholarly journals Расчетная оценка влияния неравномерности распыла топлива на поле температур газа на выходе из камеры сгорания ГТД

2021 ◽  
pp. 25-34
Author(s):  
Сергей Анатольевич Евсеев
Keyword(s):  
Numerical Simulation ◽  
Numerical Modeling ◽  
Temperature Field ◽  
Combustion Chamber ◽  
Combustion Model ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Ansys Fluent ◽  
Turbulent Schmidt Number ◽  
Design Documentation

This paper presents the results of numerical simulation of a gas flow with the combustion of atomized liquid fuel (the equilibrium combustion model pdf was used along with the model of a partially mixed mixture) in an annular combustion chamber of a gas turbine engine. Numerical modeling was carried out in the ANSYS Fluent computational complex. The purpose of the calculations was to assess the influence of the unevenness of the fuel spray specified in the design documentation and the coking of the parts of the front-line device on the radial and circumferential unevenness of the gas temperature field at the exit from the combustion chamber. The simulation used the previously verified turbulence model k-e with the functional dependence of the turbulent Schmidt number Sc on the gas temperature, which was implemented in the ANSYS Fluent computational complex using the user function (UDF). Since the fuel injector and the swirler represent a rather complex spraying scheme, which does not allow calculating the amount of fuel entering through the holes in the swirler cap, an installation was made and tests were carried out to determine the amount of the fuel-air mixture distributed over the holes in the swirler cap. The experimental values of the distribution of the air-fuel mixture through the holes in the swirler cap were further used to perform numerical simulation of combustion in the combustion chamber. Numerical modeling was carried out with sector non-uniformity equal to 0 %, 50 % (the maximum allowable according to the design documentation), and during coking of the swirler cap holes. As a result of the calculations, it was found that the sector irregularity of 50 % has an insignificant effect concerning the sector irregularity of 0 % on the radial irregularity of the gas temperature field at the exit from the combustion chamber, while the circumferential irregularity at the exit from the combustion chamber increased by 1.6 %. to the sectorial unevenness 0 %. When coking the holes of the swirler cap, the value of the radial diagram at the outlet from the combustion chamber increases by 1.2%, and the value of the circumferential irregularity increases by 4%.

scholarly journals ПОВЫШЕНИЕ ТОЧНОСТИ РАСЧЕТА ПОЛЯ ТЕМПЕРАТУР ГАЗА НА ВЫХОДЕ ИЗ КАМЕРЫ СГОРАНИЯ ГТД МЕТОДОМ ТРЕХМЕРНОГО КОМПЬЮТЕРНОГО МОДЕЛИРОВАНИЯ

2020 ◽  
pp. 74-82
Author(s):  
Сергей Анатольевич Евсеев ◽  
Дмитрий Викторович Козел ◽  
Игорь Федорович Кравченко
Keyword(s):  
Numerical Experiment ◽  
Combustion Chamber ◽  
Turbulence Model ◽  
Schmidt Number ◽  
Temperature Pattern ◽  
Gas Temperature ◽  
Ansys Fluent ◽  
Maximum Value ◽  
Turbulent Schmidt Number ◽  
Initial Settings

The problem of numerical simulation of the gas flow with the combustion of atomized liquid fuel was solved (the equilibrium combustion model pdf was used along with the partially mixed mixture model) in the annular combustion chamber of a gas turbine engine. Numerical modeling was performed in Ansys Fluent calculation complex. The purpose of the calculations was to simulate the radial and circumferential unevenness of the gas temperature pattern at the outlet of the combustion chamber. As a result of the calculations, it was found that the accuracy of modeling the radial and circumferential unevenness of the gas temperature pattern at the outlet of the combustion chamber is unsatisfactory when using the k–e turbulence model with the initial settings for the Ansys Fluent calculation complex. Moreover, the maximum value of the radial non-uniformity of the gas temperature pattern at the outlet of the combustion chamber exceeded the value obtained in the experiment by 12.61 %, and the maximum value of the circumferential non-uniformity by 12.69 %. To improve the accuracy of modeling the temperature pattern non-uniformity at the outlet of the combustion chamber, a numerical experiment was conducted to study the effect of the degree of turbulent diffusion of gas components on the value of temperature pattern non-uniformity. To reduce the non-uniformity of the temperature pattern at the outlet of the combustion chamber, the degree of turbulent diffusion of gas components was increased with respect to the initial version of the calculation, performed using the k–e model of turbulence with the initial settings for the Ansys Fluent calculation complex, by reducing the turbulent Schmidt number Sc in the turbulence model. For the initial settings of the k–e turbulence model in the Ansys Fluent calculation complex, the turbulent Schmidt number Sc = 0.85. A numerical experiment was performed for the values of Sc = 0.6, Sc = 0.4, and Sc = 0.2. The results of a numerical experiment confirmed the influence of the turbulent Schmidt number Sc on the result of calculating the gas temperature pattern at the outlet of the combustion chamber; as the value of Sc decreases, the level of the circumferential and radial non-uniformities of the gas temperature pattern decreases. However, the degree of reduction of radial and circumferential irregularities with a decrease in Sc is different. Therefore, to ensure high accuracy in calculating both the circumferential and radial non-uniformities of the gas temperature pattern, it was proposed to use a variable value of the turbulent Schmidt number Sc depending on the gas temperature instead of a constant value. The functional dependence of the turbulent Schmidt number Sc on the gas temperature was implemented in the Ansys Fluent calculation complex using the user function (UDF). The results of modeling the gas temperature pattern using the proposed UDF function for the turbulent Schmidt number Sc are in satisfactory agreement with the experimental data for both radial and circumferential non-uniformities of the gas temperature pattern at the outlet of the combustion chamber.

The Numerical Simulation Analysis of Tuyere's Temperature Field and Stress Field

2013 ◽  
Vol 706-708 ◽  
pp. 1701-1704 ◽  
Author(s):  
Xi Ping Guo ◽  
Wen Yue Han
Keyword(s):  
Numerical Simulation ◽  
Numerical Modeling ◽  
Temperature Field ◽  
Stress Field ◽  
Simulation Analysis

Research on the temperature field and stress field of tuyere by numerical modeling and analyse the influence of structure on tuyere's property.

Investigation of Numerical Simulation in Combustion Chamber Predictability

2011 ◽  
Vol 317-319 ◽  
pp. 2085-2090
Author(s):  
Rang Shu Xu ◽  
Ling Niu ◽  
Xin Zhu Weng ◽  
Long Xu ◽  
Min Li Bai
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Combustion Chamber ◽  
Domain Boundary ◽  
Combustion Model ◽  
Physical Parameters ◽  
Computational Domain ◽  
Flame Tube ◽  
Vof Model ◽  
Adopted Model

For the purpose of increasing applicability of combustion chamber simulation, computational domain, boundary condition, simplicity of complicated structures, mesh generation and physical parameters are investigated in this paper. An annular combustion chamber of some aero-engine is studied by means of predictive numerical simulation. The computational domain includes diffuser, swirler, inner flame tube, inner ring of combustion chamber and the flow channel of all the holes on the wall of flame tube. The film cooling holes row was simplified into a slit filled with porous media. Realizable k-turbulent model and non-premixed combustion model were adopted. Model of pressure atomization nozzle were calibrated and validated through inner nozzle flow property two-phase flow VOF model and experimental data. Physical parameters are express through polynomial functions. A commercial CFD code was adopted on a high performance computing cluster with parallel algorithm and the solving method are high-order discretization scheme. The velocity, pressure, temperature, fuel spray, density of fuel and productions, etc. are calculated and validated with the experimental data.

scholarly journals Numerical Simulation of the Exit Temperature Pattern of an Aircraft Engine Using a Temperature-Dependent Turbulent Schmidt Number

2021 ◽  
Vol 2021 (3) ◽  
pp. 34-46
Author(s):  
Igor F. Kravchenko ◽  
Dmytro V. Kozel ◽  
Serhii A. Yevsieiev
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Temperature Dependence ◽  
Schmidt Number ◽  
Aircraft Engine ◽  
Temperature Pattern ◽  
Temperature Dependent ◽  
Ansys Fluent ◽  
Turbulent Schmidt Number ◽  
Exit Temperature

Abstract This paper presents a numerical simulation for predicting the combustor exit temperature pattern of an aircraft engine, developed using the commercial fluid simulation software Ansys Fluent, which assumes a shape probability density function for the instantaneous chemistry in the conserved scalar combustion model and the standard k-ε model for turbulence. We found the compliance of the radial and circumferential non-uniformities of the exit temperature with the experimental data to be insufficient. To achieve much more accurate result, the mixing intensity was enhanced with respect to the initial calculation due to using the reduced value of the turbulent Schmidt number Sc. Numerical simulation was performed for values of the turbulent Schmidt number from Sc = 0.85 (default) up to Sc = 0.2, with results confirming the reduction of radial and circumferential non-uniformities of exit temperature. However, correlation between radial and circumferential non-uniformities is not admissible for these cases. Therefore, we propose to use a temperature-dependent formulation of the turbulent Schmidt number Sc, accounting for the increase in Sc number with increasing gas temperature. A user defined function (UDF) was used to implement the Sc number temperature dependence in Ansys Fluent. The numerical results for the proposed Schmidt number Sc temperature dependence were found to be in acceptable agreement with the experimental data both for radial and circumferential non-uniformities of the exit temperature pattern.

scholarly journals Effect of Fuel Injector Nozzle Hole Diameter on Emissions of CAT 3401 Diesel Engine Using CONVERGETM CFD

2019 ◽  
Vol 8 (6) ◽  
pp. 927-932
Keyword(s):  
Diesel Engine ◽  
Cone Angle ◽  
Hole Diameter ◽  
Droplet Radius ◽  
Combustion Model ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Spray Cone ◽  
Injector Nozzle ◽  
Nozzle Hole

Variation of fuel injector nozzle hole is on engine emission and performance is evaluated in present article. Simulation is carried out on caterpillar 3401 diesel engine is using CONVERGE CFD code. A 60° sector model with SAGE combustion model was considered to examine the four different nozzle hole diameters (0.230mm, 0.240mm, 0.250mm, 0.259mm and 0.270mm) and their effect on the engine performance, emissions and spray characteristics. The combustion results showed that nozzle hole diameter of 0.230mm contributed for maximum in-cylinder pressure and temperature due to enhancement in spray cone angle, atomization, and efficient air-fuel mixture. HC, CO, and soot Emissions were found to be decreased with the decrease in nozzle hole diameter, however, due to enhanced atomization and the overall increase in cylinder gas temperature, the NOx emissions were observed to increase for nozzle holes with smaller diameters. Droplet radius for 0.250mm, 0.259mm and 270 mm is found to be larger to the formation of lower jet velocities. Thus nozzle holes with smaller diameter tend to reduce the emissions with a penalty in NOx emission.

FLUID ANALYSIS AND NUMERICAL SIMULATION OF A LUNG SIMULATOR WITH COPPER WOOL

2017 ◽  
Vol 29 (04) ◽  
pp. 1750030
Author(s):  
Rongguo Yan ◽  
Tserentogtokh Bayaraa ◽  
Xiaoye Qiu ◽  
Junguo Li
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Ideal Gas ◽  
Gas Temperature ◽  
Glass Bottle ◽  
Ansys Fluent ◽  
Isothermal Conditions ◽  
Fluid Analysis ◽  
Lung Simulator ◽  
The Ideal

A mechanical lung simulator is an important tool to simulate the severity of lung disease. In this paper, a lung simulator is proposed, which is composed of a glass bottle, a pressure sensor, copper wool, etc. Its working mechanism is based upon the ideal gas equation. The glass bottle simulates human lung, and copper wool is used to quickly keep gas temperature in the bottle stable. The main issue discussed is about how much copper wool is appropriate to approximate isothermal conditions when copper wool is uniformly placed in the lung simulator. Three aspects including (1) theoretical fluid analysis, computation, and derivation based upon the ideal gas equation; (2) three-dimensional geometric meshing and numerical simulation based upon the ANSYS FLUENT; and (3) the experiment reveals that copper wool corresponding to 2–3% by volume of the lung simulator is enough to quickly keep gas temperature in the lung simulator stable and to realize quasi-isothermal conditions.

Numerical Simulation of Detonation in Fine Aluminum-Oxygen Mixtures with Hybrid Combustion Model

2013 ◽  
Vol 748 ◽  
pp. 3-6
Author(s):  
Xiang Long Yang ◽  
Zhou Xiao Qing ◽  
Yang Lei ◽  
Zhong Wei Huang
Keyword(s):  
Numerical Simulation ◽  
Detonation Wave ◽  
Wave Structure ◽  
The Other ◽  
Combustion Model ◽  
Gas Temperature ◽  
Other Hand ◽  
Detonation Structure ◽  
Pressure Profiles

The detonation of fine aluminum-oxygen mixtures was numerical simulated using a hybrid combustion model. The emphasis was laid on the influence of the decomposition of Al2O3 on the detonation structure. Results showed that including the decomposition of Al2O3 will limit the gas temperature behind the detonation wave below a certain value. On the other hand, a double-wave structure will appear in the pressure profiles in cases with rich-dust condition if the decomposition of Al2O3 is not included.

Numerical Simulation of the Effects of the Nozzle Parameters on In-Cylinder Fuel and Air Mixing Process

2013 ◽  
Vol 401-403 ◽  
pp. 218-221
Author(s):  
Qi Liu ◽  
Guang Yao Ouyang ◽  
Shi Jie An ◽  
Yu Peng Sun
Keyword(s):  
Numerical Simulation ◽  
Diesel Engine ◽  
Fuel Injection ◽  
Combustion Model ◽  
Engine Fuel ◽  
Three Dimension ◽  
Mixing Process ◽  
Fuel Injector ◽  
Injection Process ◽  
Air Mixing

In order to study the injection property of diesel engine fuel injector, the three-dimension combustion model of TBD620 diesel engine is constructed on the AVL Fire software platform. A numerical simulation of the two injectors’ fuel injection process at different load conditions has been done. The influence on fuel and air mixing process is analyzed. The results show that the special injector has a good performance at low load, but the standard injector is more favorable for fuel and air fully mixing at high load.

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