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.

scholarly journals EFFECT OF HYSTERESIS IN AXIAL COMPRESSORS OF GAS-TURBINE ENGINES

Aviation ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 97-102 ◽  
Author(s):  
Mykola Kulyk ◽  
Ivan Lastivka ◽  
Yuri Tereshchenko
Keyword(s):  
Gas Turbine ◽  
Axial Compressor ◽  
Separated Flow ◽  
Aerodynamic Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Bladed Disks ◽  
Axial Compressors

The phenomenon of separated flow hysteresis in the process of the streamlining the axial compressor of gas-turbine engines is considered. Generalised results of research on the occurrence of hysteresis in the aerodynamic performance of compressor grids and its influence on the performance of the bladed disks of compressors that operate in real conditions of periodic circular non-uniformity are demonstrated.

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.

Multidisciplinary Design Optimization of a Bladed Disc for Small-Size Gas-Turbine Engines

2019 ◽  
Author(s):  
Anton Salnikov ◽  
Maxim Danilov
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
3D Model ◽  
Strength Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Bladed Disks ◽  
Computational Region ◽  
Bladed Disk ◽  
Multidisciplinary Model

Abstract One of the most important units of small-size gas-turbine engines (GTE) is a turbine bladed disk, since it determines the total engine efficiency. Designing a turbine disks is a complex challenge due to the high loads and a large number of structural and technological constraints, as well as a variety of requirements to the bladed disks for small-size GTEs (higher efficiency, lower mass and adequate strength characteristics, etc.). Diverse requirements to the turbine bladed disks mean that modifying the structure in order to improve some characteristics will degrade other characteristics. A standard solution to this problem is to use the iterative approach, which reduces the design process to a consecutive iteration of setting and solving design problems concerning the bladed disk elements (blade and disk) separately for different aspects. The main drawback of this approach is its tremendous labor intensity and inferior quality of design, as this procedure does not consider the design object as a single entity. This paper proposes an approach to the turbine bladed disks design based on the use of a single multidisciplinary parametrized 3D model that contains several specialized submodels. These submodels define the essential computational regions, as well as the characteristics of the physical processes and phenomena in the object under study. The model also enables integration and interaction of the submodels in a single computational region. The single multidisciplinary model is modified and analyzed automatically, so the design problem is transformed into a multi-criteria optimization problem where the weight, gas dynamic and strength characteristics are used as criteria or constraints, and they are improved by varying the geometric parameters of the blade and disk. Each submodel simulates and analyzes the essential characteristics at the level comparable to the standard engineering calculations. Therefore, the designs obtained as a result of optimization do not need significant improvements, which facilitates and enhances the design process. The development of an integrated model is time consuming, but since the design and operation of bladed disks are similar, the created parametrized multidisciplinary 3D model can be used in the design of other similar disks after minor alternations taking into account the specifics of the new task.

Optimisation Method for Multistage Compressors

2021 ◽  
pp. 38-59
Author(s):  
E.S. Goryachkin ◽  
V.N. Matveev ◽  
G.M. Popov ◽  
O.V. Baturin ◽  
Yu.D. Novikova
Keyword(s):  
Gas Turbine ◽  
Cfd Simulation ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Stability Margin ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Data Vector ◽  
Minimum Number ◽  
Multistage Compressors

The paper presents an algorithm for seeking an optimal blade configuration for multistage axial-flow compressors. The primary tool behind the algorithm is 3D CFD simulation, augmented by commercial optimisation software. The core of the algorithm involves feeding an initial data vector to the parametric simulation module so as to form a "new" blade geometry, which is then transferred to 3D computational software. The results obtained are further processed in a program that implements the algorithm for seeking the optimum and forms a new input data vector to achieve the set goal. We present a method of parametrically simulation the blade shape, implemented in a software package, making it possible to describe the shape of the compressor blade profiles using a minimum number of variables and to automatically change the shape in the optimisation cycle. The algorithm developed allows the main parameters of compressor operation (efficiency, pressure ratio, air flow rate, etc.) to be improved by correcting the profile shape and relative position of the blades. The algorithm takes into account various possible constraints. We used the method developed to solve practical problems of optimising multistage axial compressors of gas turbine engines for various purposes, with the number of compressor stages ranging from 3 to 15. As a result, the efficiency, pressure ratio and stability margin of gas turbine engines were increased

scholarly journals A Review of the Bases of Predicting Heat Transfer to Gas Turbine Rotor Blades

1974 ◽  
Author(s):  
A. Brown ◽  
B. W. Martin
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Mainstream Flow ◽  
Streamwise Pressure Gradient

This paper reviews the methods for predicting boundary-layer behavior on flat and curved surfaces under conditions experienced in gas turbine engines and the resultant heat transfer to the turbine rotor blades. Particular attention is given to the effects of streamwise pressure gradient and the intensity of mainstream turbulence on transition phenomena. The time-mean heat transfer across a boundary-layer under unidirectional oscillatory mainstream flow, such as might be initiated in a combustion chamber, is considered. The relevance of flat plate predictions and correlations to rotating turbine blades is also discussed.

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