Combustion Chamber Of Gas Turbine Engine Research Articles

Experimental study results of the front-end device with two-tier air burner as part of the gas turbine engine combustion chamber

In recent years, the gas turbine power plant has been increasingly used in various industries in Kazakhstan. The reasons for this are: thermal efficiency, simplicity of the thermal scheme and design, small mass per power unit, high maneuverability, low toxicity, and relatively simple automation of operation. This paper presents the experimental study results of a two-tier air burner as the part of the gas turbine engine combustion chamber at burning liquid fuel. ? new design of a microflame device was developed. Two-tier burner makes possible the combustion process in a number of discrete zones, i.e. microflame combustion. During the experiment, the installation angles of the blades of the external and internal registers, as well as the ratio of the coefficients of excess air in the tiers, were changed. The experimental studies of a two-tier burner confirmed the possibility to increase fuel combustion efficiency, a low degree of temperature field unevenness and to decrease NOx emission.

Kinetic model and kerosene surrogate for calculating gas turbine engine emission of carcinogenic hydrocarbons

To calculate the emission of carcinogenic polycyclic aromatic hydrocarbons by the combustion chambers of aircraft gas turbine engines, the A17 kinetic model has been developed, characterized by new blocks of elementary chemical reactions of hydrocarbon compounds oxidation and synthesis of polycyclic aromatic hydrocarbons. The results of model validation showed satisfactory agreement with the experimental data and the possibility of applying the model to describe combustion processes in gas turbine engine combustion chambers. A review and numerical study was carried out for 14 surrogates (model fuels) of aviation kerosene, the combustion of which can be described using the A17 model. Simulation of stabilized flame of a previously prepared mixture showed the effectiveness of Drexel, Liu, su4, UM1 surrogates, the predictions for which agree satisfactorily with the experimental data and provide the expected levels of concentration of polycyclic aromatic hydrocarbons. The calculations show the dependence of the concentration of the most carcinogenic polycyclic aromatic hydrocarbon benzo(a)pyrene, and the ratio of the main combustion products CO2/H2O on the molar mass of the fuel. For the experimentally determined value of the molar mass of kerosene TS-1, the smallest deviation (up to 0.25%) is demonstrated by the su4 and UM1 surrogates. Due to the best predictive capability for the ignition delay time, normal flame propagation speed, pyrolysis and combustion products, the su4 and UM1 surrogates can be chosen to calculate the emission of carcinogenic polycyclic aromatic hydrocarbons from aircraft gas turbine engine combustion chambers.

Оцінка впливу експлуатаційних параметрів на роботу авіаційного газотурбінного двигуна

This paper considers the possibilities of improving the reliability and efficiency of the aircraft engine, which are one of the main indicators of quality and require high-quality fuel. Modern gas turbine engines (GTE) are much more powerful and economical compared with those produced 50 years ago. Nevertheless, manufacturers are constantly working to improve gas turbine engines with the main emphasis on their fuel efficiency. Mechanical impurities present in the fuel can clog the fuel filters, thereby cutting off the fuel supply. The presence of resins in the fuel leads to the formation of various deposits on engine parts, and the content of sulfur, acids and alkalis increases the corrosiveness of the fuel. The completeness of combustion and the tendency of carbon formation are the main performance characteristics of hydrocarbon fuels, which are of great practical importance in improving the efficiency and service life of the engine. Currently, there are many options for improving technical and economic indicators. The proposed ways to prepare a better fuel mixture before supplying it to the engine. The preparation of aviation fuel is carried out because of the electrophysical effects on the fuel. The electrophysical effect on the fuel is determined by a magnetic installation with a sign-changing magnetic field. Studies were conducted to determine the effect of electrophysical impact on the completeness of combustion of aviation fuel and carbon formation in the combustion chamber of a gas turbine engine. The method allows to give a comparative assessment of the completeness of combustion and carbon formation of fuels for engines with a small amount of fuel consumed for testing. It has been established that under electrophysical action on aviation fuel, the fuel combustion efficiency increases by 10...12 %, carbon formation in the gas turbine engine combustion chamber decreases by 20...25 %. The positive effect on the combustion process in the previous phases decreases the afterburning phase, therefore, a decrease in the temperature of the exhaust gases, a decrease in the concentration of nitrogen oxide by 12...16 %, carbon monoxide by 0.64...0.7 % and hydrocarbon by 25...35 %. After the electrophysical impact and the fuel running time, the content of resinous compounds increased four times, the content of oxygen compounds decreased by ~23 %, and the content of sulfur compounds decreased by ~25 %.

Adaptive fuzzy gas turbine engine combustion chamber temperature meter

Adaptive fuzzy gas turbine engine combustion chamber temperature meter

Моделювання якісного складу паливно-повітряної суміші у факельному запальнику камер згоряння ГТД

The qualitative composition of the fuel-air mixture, which is formed in the torch igniter of the combustion chamber of the gas turbine engine (GTE), determines the efficiency and reliability of their work. The main task of the study is to determine the qualitative composition of the fuel-air mixture near the electric spark plug of the GTE torch igniter depending on its geometric features and engine operation condition. The composition of the mixture was evaluated using analytical, experimental, and numerical methods. According to the analytical model, a significant over-enrichment of the fuel-air mixture in the igniter housing was established and confirmed experimentally. A numerical model was used to determine the fields of mass concentration of fuel particles in the fuel-air mixture in the torch igniter housing, considering the peculiarities of airflow and fuel supply for different combinations of GTE design features and operating conditions. The influence of geometric parameters of the housing and external factors was investigated using the numerical model of stationary combustion of fuel-air mixture, which was prepared in the torch igniter housing of GTE combustion chamber by evaporation and spraying of aviation kerosene particles in the air stream. The implementation of a small-factor experiment allowed to establish the degree of influence of each factor under study and their interaction on the excess air coefficient. The correlation coefficient between the coefficient of excess air near the spark plug and the average flame temperature is set. Given the absence of serial designs of controller torch ignites, it is proposed to use a pulsed fuel supply to control the quality of the fuel-air mixture. Further ways of research to increase the reliability of ignition of both the torch igniter from the electric spark plug and the combustion chamber of GTE from the flame is outlined.

Analysis of Possible Operational Defects in and Damages to the Gas Turbine Drives of Gas Pumping Units and Techniques for Their Diagnostics

Modern gas pumping units quite often use gas turbine drives adapted to ground operating conditions. The distribution of failures occurring in such a gas pumping unit tilts towards the engine. The resulting failures can be distributed between various assemblies of the gas turbine drive, but practice shows that the combustion chamber of a gas turbine engine (GTE) is the most dangerous from the standpoints of reliability and safety.The paper considers the gas turbine drive failure flow distribution. Specific malfunctions inherent in the combustion chamber of a gas turbine engine and their causes such as fuel pressure pulsation, a local increase in the gas flow temperature, flameout or cessation of combustion, damage and burnout of flame tubes, deposits on the combustion chamber elements, fuel injector blockage or burnout, and incomplete fuel combustion have been described in detail.The paper also proposes a technique developed by the authors for determining the GTE combustion chamber malfunctions by oscillation parameters using a mathematical model explaining the occurrence of certain modulations reflecting specific engine malfunctions.

A Two-Parameter Corresponding States Method for Calculating the Steady-State Evaporation Rate of C2\u2013C9 n-Alkane Droplets in Air for Elevated Pressures and Temperatures

Advanced gas turbine and internal combustion engine combustion chambers operate at highly elevated pressures and temperatures. Therefore, spray vaporization analysis cannot be limited to the atmospheric environment since evaporation strongly depends on ambient conditions. Presently, the effect of air pressure and temperature on droplet evaporation rate was investigated by using both a transient and a steady-state approach. A corresponding states model was derived for the steady-state evaporation rate for n-alkanes in the range of C2–C9 with an excellent fit quality and < 1% model uncertainty, considering the thermophysical data uncertainties. The model was tested for C1, C10, and C12 n-alkanes as well with low success. The ambient conditions were evaluated in terms of reduced pressures and temperatures, covering the range of 0.02–0.5 and 1.2–1.5, respectively. However, the applicability of the model was limited to reduced temperature of 1.3–1.5, as higher discrepancy was observed between the trends of the different n-alkanes at lower temperatures. Since the heat-up phase of practical sprays in combustion chambers is often short, the present model might significantly reduce the computational effort required for liquid evaporation calculations.

Burner geometry impact on gas turbine engine combustion chamber characteristics

Burner geometry impact on gas turbine engine combustion chamber characteristics

Swirler blades installation angle impact on flow mixing efficiency behind the flame tube head of gas turbine engine combustion chamber

Swirler blades installation angle impact on flow mixing efficiency behind the flame tube head of gas turbine engine combustion chamber

The Flame Stabilization and Calculation of the Stall Characteristics of Gas Turbine Engine Combustion Chamber

The results are presented of the experimental and computational studies of the flame stabilization behind a swirler in an open flow and in a model compartment of the combustion chamber. Using the thermal theory, the calculation model of the flame stabilization in the combustion chamber is developed. Using this model, the calculation is carried out and the calculated and experimental data are compared.

ОПТИМІЗАЦІЯ КОНСТРУКЦІЇ ФАКЕЛЬНОГО ЗАПАЛЬНИКА ГТД ЧИСЕЛЬНИМ МЕТОДОМ

Solved the problem of gas-turbine engine combustion chamber flame igniter efficiency increasing by increasing the flame temperature via optimizing the body design. To determine the influence of the igniter body various geometric parameters, affecting the formation and combustion of the fuel-air mixture, a parametric model was developed. This model together with the developed project in the ANSYS Workbench software package made it possible to automate the modeling process. The influence of the geometric parameters of the igniter body and external factors on the average flame temperature has been studied via a numerical model of the stationary combustion process of the air-fuel mixture formed inside the igniter of the combustion chamber of a gas turbine engine by evaporation and spraying particles of aviation kerosene in the air stream. The adequacy of the numerical simulation results was confirmed by the implementation of a series of full-scale experiments using the Fisher criterion.The uniformity of temperature and adequacy of the average temperature estimation algorithm was established using the correlation analysis of the results of measured temperature at various points of the flame. To determine the degree and nature of their influence, sequentially screening (fractional), as well as full-factor experiments with varying factors at two and three levels were implemented. Based on the results of the analysis of variance, the most statistically significant factors were selected. A regression dependence was established that relates the diameter of the air inlet orifice and the air pressure drop to the flame temperature. A qualitative and quantitative assessment of the influence of the considered factors on the process of formation of a hot air mixture and its combustion has been performed. The optimal values of the geometric parameters of the igniter body and its operating conditions are determined under which the maximum flame temperature at the stationary combustion stage is ensured. Relationships between design features, igniter operation mode, and the temperature of the flame are established. This allows expanding the range of stable ignition of gas turbine engine combustion chambers in accordance with the design of the igniter, the starting fuel supply mode, and the air pressure drop.

Simulation of the operating conditions in a gas turbine engine combustion chamber

Simulation of the operating conditions in a gas turbine engine combustion chamber

Setting up the mathematical model of gas fuel combustion taking into account computational domain geometry refinement

The problem of gaseous fuel combustion in a land-used gas turbine engine combustion chamber was formulated, and the results of the numerical solution were described. The paper assumes that the gas-air mixture is a single-phase, multicomponent and reactive flow. The Reynolds averaging approach to the Navier-Stokes equations was used to describe the turbulent flow in the combustion chamber. The SST model of turbulence was used to close the averaged system .A combined EDM/FRC combustion model was used to determine the rate of formation of mixture components. A technique was proposed for setting up the mathematical model taking into account three parameters: the turbulent Prandtl and Schmidt numbers and the coefficient limiting the burning rate. Based on a comparison of the results of preliminary calculations and experiments, it was suggested that the difference in these data is due to technological deviations and the application of a heat-protective coating to the walls of the flame tube. The geometry of the computational domain was changed based on the airflow coefficient obtained in the aerodynamic tests. The setting up of the mathematical model was carried out both on the initial and on the refined geometry. The verification of the mathematical model was carried out using the results of experiments on three structural variants of the flame tube. The results of calculations carried out with the use of refined data showed that a change in geometry made it possible to more correctly describe combustion in a turbulent flow: the theoretical results on the average non-uniformity obtained on the refined geometry of the studied region practically coincide with the experimental data. Due to updating the geometry of the computational domain, it was possible to establish the location and magnitude of the maximum non-uniformity. Using the results obtained in this work, a mathematical model was developed to describe the combustion of gaseous fuel in the combustion chamber of a gas turbine engine. The proposed model can be used to further optimize the design of the combustion chamber.

Circumferential Distortion (Temperature) Reduction of a Small-Size Gas Turbine Engine Combustion Chamber by Numerical Experimentation

Circumferential Distortion (Temperature) Reduction of a Small-Size Gas Turbine Engine Combustion Chamber by Numerical Experimentation

Development of blend composition of aviation kerosene surrogate for the simulation of workflow of gas turbine engine combustion chamber

In this paper, the criteria for determining the composition and physicochemical properties of aviation kerosene were formulated. The data on the physicochemical properties of known kerosene surrogates were systematized and classified. The main classes of individual chemical components of aviation kerosene were determined, and the main representatives of these classes which were used in the preparation of surrogates, were investigated. Four- and six-component kerosene substitutes are proposed. The physical properties of the developed surrogates were validated according to the flow characteristics and the spray angle of the flame of a centrifugal fuel nozzle. The dependence of the flame speed on the composition of the mixture of developed kerosene surrogates was determined. The results of determining the composition of combustion products during the combustion of TS-1 brand aviation kerosene and its surrogates in a model combustion chamber were compared.

Optimization of fuel distribution in the afterburner of a gas turbine engine

The use of 3-D simulation programs and in particular NX and ANSYS simulators brought the design and fine tuning of gas turbine engine combustion chambers to the next level, as it allows improving the performance (increased combustion efficiency, reduced radial and circumferential non-uniformity of the total gas temperature), as well as determining the weak points of the structure. The article analyzes the flow of fuel jets from the finger sprayers of the afterburner of the combustion chamber of a gas turbine engine. The problem of optimizing the distribution of fuel is formulated: the fuel at the exit of the flame tube is to be evenly distributed by varying the diameters of the holes in the fuel manifolds. Restrictions are imposed on the optimization problem the supply of fuel to the peripheral zone at the outlet of the afterburner is reduced by a factor of five. The optimization effect is verified by comparing the fuel combustion efficiency in the case of standard fuel distribution with the optimized distribution option using the NX and ANSYS 3-D simulations. As a result, we observe an increase in combustion efficiency in all afterburner modes of engine operation.

Comparative analysis of fuel distribution downstream of the gas-dynamic flame holder with various methods of injection

The article deals with the problems of atomization and distribution of liquid fuel in a swirling flow downstream of the front-end gas-dynamic stabilizer designed for the use in gas turbine engine combustion chambers. The task is to compare the distributions of droplet-liquid fuel in the wake of the stabilizer when the fuel is injected from the side and end surfaces of the device in question. It is shown that the calculations performed according to a stationary model are qualitatively different from the non-stationary ones in both fuel supply options. However, in the first approximation, the distributions of liquid droplet fuel fed from the side and end surfaces of the stabilizer are similar. An experimental study of the spray characteristics was conducted by the Shadowgraphy method of diagnosing droplet-air fluxes with the fuel supplied at an azimuthal angle of 45 from the side surface of the gas-dynamic stabilizer. It is shown that if the fuel is injected at an angle it leads to a change in the velocity distribution in the wake of the stabilizer, and the flow swirl opposite to direction of azimuth fuel supply expands the spray pattern.

Исследование формирования температурных полей в камерах сгорания газотурбинных двигателей

Исследование формирования температурных полей в камерах сгорания газотурбинных двигателей

Increasing the Ecological Efficiency of Combustion Chambers in Gas-Turbine Engines Using Low-Current Plasmochemical Stabilizers

Consideration is given to the numerical experiment carried out using the state-of-the-art tools of computational hydrodynamics to predict the emission level of toxic components at the engine design stage that would allow for a considerable reduction of expenditures required for the engine design and its development and also increase the operation efficiency of power systems. The purpose of this research was to increase the ecological efficiency of the combustion of gaseous fuel in the low-emission combustion chambers of gas turbine engines (GTE) due to the use of low-current plasmochemical stabilizers. The theoretical research done showed that the use of low current plasmochemical stabilizers for low-emission combustion chambers of GTE enables to expand the range of stable operation of the fuel firing device and decrease the emission level of toxic components. Theoretical investigation of pulsation performances of the low-emission combustion chamber with a preliminary mixing of the fuel-&-air mixture of GTE 25 MW allowed us to establish that the plasmochemical stabilization of processes in the combustion chamber would enable an increase in the service life of flue tubes and gas-turbine engines on the whole, getting an economic effect due to the reduction of the emissions of toxic components.

Influence of Simplifying a Geometrical Model of the Gas Turbine Engine Combustion Chamber on the Results of Numerical Modeling

We studied the geometric models of combustion chambers depending on their simplification. It is shown that the error in calculating the parameters does not exceed 8 % under the constraint of the geometrical model of the gas turbine engine (GTE) combustion chamber by an angular sector with a burner device.