scholarly journals Gas-Dynamic Methods to Reduce Gas Flow Nonuniformity from the Annular Frames of Gas Turbine Engines

2018 ◽  
Vol 302 ◽  
pp. 012025
Author(s):  
D Kolmakova ◽  
G Popov
Keyword(s):  
Gas Turbine ◽  
Gas Flow ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Dynamic ◽  
Dynamic Methods ◽  
Flow Nonuniformity

scholarly journals Інтелектуальний регулятор запасу газодинамічної стійкості компресора авіаційного ГТД

2021 ◽  
pp. 48-52
Author(s):  
Сергій Васильович Єнчев ◽  
Сергій Олегович Таку
Keyword(s):  
Fuzzy Logic ◽  
Nonlinear Systems ◽  
Fuzzy Control ◽  
Control Systems ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Harmonic Linearization ◽  
Gas Dynamic

The gas-dynamic stability of compressors of aircraft gas turbine engines is one of the most important conditions that determine their reliability and level of flight safety. Unstable operation of the compressor in the engine system (surge) leads to loss of thrust accompanied by an increase in gas temperature in front of the turbine and increased vibration because of large amplitudes of pressure pulsations and mass flow through the engine path. To improve the parameters of ACS aviation gas turbine engines are increasingly using regulators built using fuzzy logic algorithms. The implementation of fuzzy control algorithms differs from classical algorithms, which are based on the concept of feedback and reproduce a given functional dependence or differential equation. These functions are related to the qualitative assessment of system behavior, analysis of the current changing situation, and the selection of the most appropriate for the situation supervision of the gas turbine engine. This concept is called advanced management. ACS gas turbine engines with fuzzy regulators are nonlinear systems in which stable self-oscillations are possible. Approximate methods are used to solve the problems of analysis of periodic oscillations in nonlinear systems. Among them, the most developed in theoretical and methodological aspects is the method of harmonic linearization. The scientific problem is solved in the work – methods of synthesis of intelligent control system with the fuzzy regulator as a separate subsystem based on the method of harmonic linearization and design on its basis of fuzzy ACS reserve of gas-dynamic stability of aviation gas turbine engine. Based on the analysis of the principles of construction of fuzzy control systems, it is shown that the use of fuzzy logic provides a new approach to the design of control systems for aviation gas turbine engines in contrast to traditional control methods. It is shown that the fuzzy controller, as the only essentially nonlinear element when using numerical integration methods, can be harmonically linearized. Harmonic linearization allows using the oscillation index to assess the quality in the separate channels of fuzzy ACS aviation gas turbine engines. A fuzzy expert system has been developed for optimal adjustment of the functions of belonging of typical fuzzy regulators according to quality criteria to transients.

scholarly journals Calculation of a 3D turbulent flow in aircraft gas turbine engine ducts

2020 ◽  
Vol 2020 (4) ◽  
pp. 65-71
Author(s):  
Yu.A. Kvasha ◽  
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flow ◽  
Gas Turbine ◽  
Gas Flow ◽  
Turbine Engines ◽  
Gas Flows ◽  
Gas Turbine Engines ◽  
Compressor Inlet ◽  
Air Intake ◽  
Engine Compressor

This work is devoted to the development of approaches to the numerical simulation of 3D turbulent gas flows in different ducts of aircraft gas turbine engines, in particular in inlet device ducts. Inlet devices must provide large values of the total pressure recovery factor and flow uniformity at the engine compressor inlet. The aim of this work is the verification of the operability of a technique developed earlier for the calculation of the parameters of a 3D turbulent flow in complex-shape ducts. The basic approach is a numerical simulation of 3D turbulent gas flows on the basis of the complete averaged Navier¬–Stokes equations and a two-parameter turbulence model. The proposed technique of numerical simulation of a 3D gas flow was tested by calculating a 3D laminar flow in a square pipe bent at a right angle. The calculated flow pattern is in satisfactory agreement with the experimental data on the flow structure in a pipe elbow reported in the literature. Based on a numerical simulation of a 3D turbulent flow in the air duct of one of the air intake configurations for an aircraft turboprop engine, the efficiency of that configuration is assessed. The calculated flow parameter nonuniformity at the air intake outlet, i. e., at the compressor inlet, is compared with that obtained earlier for another air intake configuration for the same engine. It is pointed out that the air intake configuration considered earlier provides a much more uniform flow parameter distribution at the engine compressor inlet. On the whole, this work shows that the quality of subsonic air intakes for aircraft gas turbine engines can be assessed using the proposed numerical technique of 3D gas flow simulation. The results obtained may be used in the aerodynamic improvement of inlet devices for aircraft engines of different types.

Techniques and Methods to Improve the Dynamic Strength of Gas Turbine Engines Compressor Rotor Wheels

2014 ◽  
Author(s):  
Daria Kolmakova ◽  
Grigorii Popov ◽  
Aleksandr Shklovets ◽  
Aleksandr Ermakov
Keyword(s):  
Gas Turbine ◽  
Calculation Method ◽  
Gas Flow ◽  
Dynamic Strength ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Cfd Model ◽  
Compressor Blades ◽  
Compressor Rotor ◽  
Pressure Compressor

The approaches to reducing the alternating stresses in the compressor blades, arising at a resonance, are discussed in paper. Maximum alternating stresses in blades of the fifth stage of intermediate pressure compressor (IPC, that operating under the gas flow circumferential variation conditions, are defined on the basis of the forced blade oscillations calculation method. Parametric CFD-model which allows to introduce different stagger angles and circumferentially alternating blade pitch at the guide vanes of IPC fifth stage was created to reduce the stresses. The flow circumferential variation was reduced by changing these parameters and as a consequence the resonant stresses were decreased by more than 2.5 times.

scholarly journals Design and development of combustion chambers for gas turbine engines based on calculations of various levels of complexity

2021 ◽  
Vol 20 (3) ◽  
pp. 7-23
Author(s):  
Y. B. Aleksandrov ◽  
T. D. Nguyen ◽  
B. G. Mingazov
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Combustion Process ◽  
Three Dimensional ◽  
Numerical Calculations ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Combustion Chambers ◽  
Flame Tube

The article proposes a method for designing combustion chambers for gas turbine engines based on a combination of the use of calculations in a one-dimensional and three-dimensional formulation of the problem. This technique allows you to quickly design at the initial stage of creating and development of the existing combustion chambers using simplified calculation algorithms. At the final stage, detailed calculations are carried out using three-dimensional numerical calculations. The method includes hydraulic calculations, on the basis of which the distribution of the air flow passing through the main elements of the combustion chamber is determined. Then, the mixing of the gas flow downstream of the flame tube head and the air passing through the holes in the flame tube is determined. The mixing quality determines the distribution of local mixture compositions along the length of the flame tube. The calculation of the combustion process is carried out with the determination of the combustion efficiency, temperature, concentrations of harmful substances and other parameters. The proposed method is tested drawing on the example of a combustion chamber of the cannular type. The results of numerical calculations, experimental data and values obtained using the proposed method for various operating modes of the engine are compared.

scholarly journals RAISING GAS-DYNAMIC STABILITY MARGIN OF AXIAL AND CENTRIFUGAL COMPRESSOR STAGES BY MEANS OF VANED DIFFUSER BOUNDARY LAYER CONTROL / DUJŲ DINAMINIO STABILUMO RIBOS AŠINIO IR IŠCENTRINIO KOMPRESORIAUS PAKOPOSE DIDINIMAS ATLIEKANT STABILIZUOTO DIFUZORIAUS PARIBIO SLUOKSNIO KONTROLĘ

Aviation ◽  
2011 ◽  
Vol 15 (3) ◽  
pp. 76-81 ◽  
Author(s):  
Ivan Lastivka
Keyword(s):  
Boundary Layer ◽  
Gas Turbine ◽  
Stability Margin ◽  
Flow Regulation ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Bladed Disks ◽  
Passive Flow ◽  
Gas Dynamic ◽  
Layer Control

Generalised research results that consider the upgradability of axial and centrifugal gas turbine engine compressors by means of gas-dynamic boundary layer control on bladed disks are demonstrated. Active and passive methods are used. Comparative analysis of the results has been carried out. The analysis is purposed to determine the influence of the flow circulation around the aerofoils on the performance of compressor single-row bladed disks with smooth blades and rough blades and under the condition that vortex generators are installed. An increase in the efficiency of aviation gas-turbine engines and in their gas-dynamic stability margin support leads to the enhancement of the parameters and performance of compressors: increase in loading of aerodynamic bladed disks, improvement of their economical efficiency, improvement of margin of the continuous flow around the compressor grids, etc. Airflow in the compressor grid is characterised by the flow region in the flow core and also by the flow regions in the wall boundary layers on the grid blades where shock waves, vortices, air swirls, and flow separation phenomena take place. The principle objective of the work is to research the possibilities of influence on the parameters of the elements of compressors and overall performance of gas-turbine engines via the methods of active and passive flow regulation. Active flow regulation is realised either by rendering the auxiliary gas mass to the blades boundary layer, or by suction (withdrawal) of the boundary layer (its part) from the surfaces of blades. Passive flow around regulation is characterised by influence on the boundary layer by means of energy redistribution in the flow itself. Santrauka Šiuo tyrimu siekiama nustatyti sparno profilio aptekejimo įtaką vienos eiles menčių kompresoriaus su lygiomis ir šiurkščiomis mentemis darbui, esant įdiegtiems sūkurio generatoriams. Pagrindinis darbo tikslas – ištirti kompresoriaus elementų ir bendro dujų turbininių variklių darbo įtaką parametrams, taikant pasyvų ir aktyvų srauto reguliavimo metodus. Padidinus dujų turbininių variklių našumą ir jų dujų dinamikos stabilumo ribas, pagereja kompresorių darbas ir parametrai: padideja aerodinaminių diskų su mentemis apkrova, jie tampa ekonomiškai našesni, padideja nepertraukiamo srauto riba aplink kompresoriaus plokšteles.

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