scholarly journals On the effect of the meridional contour shape on the power characteristics of a centrifugal compressor wheel

2020 ◽  
Vol 2020 (3) ◽  
pp. 12-17
Author(s):  
Yu.A. Kvasha ◽  
◽  
N.A. Zinevych ◽  
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Computational Study ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Compressor Wheel ◽  
Power Characteristics ◽  
Contour Shape ◽  
Wide Range ◽  
Uniformly Distributed Sequence

This work is concerned with the development of approaches to the optimal aerodynamic design of centrifugal compressor wheels, which is due to the use of centrifugal stages in compressors of modern aircraft gas turbine engines and power plants. The aim of this work is a computational study of the effect of the meridional contour shape of a centrifugal compressor wheel on its power characteristics. The basic method is a numerical simulation of 3D turbulent gas flows in centrifugal wheels on the basis of the complete averaged Navier¬–Stokes equations and a two-parameter turbulence model. The computational study features: varying the shape of the hub and tip part of the meridional contour over a wide range, formulating quality criteria as the mean integral values of the wheel power characteristics over the operating range of the air flow rate through the wheel, and a systematic scan of the independent variable range at points that form a uniformly distributed sequence. As a result of multiparameter calculations, it was shown that in the case of a flow without separation in the blade channels of a wheel with a given starting shape of the meridional contour, varying that shape has an insignificant effect on the wheel power characteristics. It is pointed out that in similar cases it seems to be advisable to aerodynamically improve centrifugal wheels by varying the shape of their blades in the circumferential direction rather than in the meridional plane. This conclusion was made using rather a “coarse” computational grid, which, however, retains the sensitivity of the computed results to a variation in the centrifugal wheel geometry. On the whole, this work clarifies ways of further aerodynamic improvement of centrifugal compressor impellers in cases where the starting centrifugal wheel is a well-designed wheel with a flow without separation in the blade channels. The results obtained may be used in the aerodynamic optimization of centrifugal stages of aircraft gas turbine engines.

Design, Development and Application of Vehicle Gas Turbine Engines

1966 ◽  
Vol 181 (1) ◽  
pp. 149-172
Author(s):  
P. A. Phillips ◽  
Peter Spear
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Low Cost ◽  
Engine Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Design Development ◽  
Turbine Engine ◽  
Wide Range ◽  
Cycle Temperature

After briefly summarizing worldwide automotive gas turbine activity, the paper analyses the power plant requirements of a wide range of vehicle applications in order to formulate the design criteria for acceptable vehicle gas turbines. Ample data are available on the thermodynamic merits of various gas turbine cycles; however, the low cost of its piston engine competitor tends to eliminate all but the simplest cycles from vehicle gas turbine considerations. In order to improve the part load fuel economy, some complexity is inevitable, but this is limited to the addition of a glass ceramic regenerator in the 150 b.h.p. engine which is described in some detail. The alternative further complications necessary to achieve satisfactory vehicle response at various power/weight ratios are examined. Further improvement in engine performance will come by increasing the maximum cycle temperature. This can be achieved at lower cost by the extension of the use of ceramics. The paper is intended to stimulate the design application of the gas turbine engine.

The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Correction Factors ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Nitrogen Emission ◽  
Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

scholarly journals METHOD OF FORMULATING INPUT PARAMETERS OF NEURAL NETWORK FOR DIAGNOSING GAS-TURBINE ENGINES

Aviation ◽  
2013 ◽  
Vol 17 (2) ◽  
pp. 52-56 ◽  
Author(s):  
Mykola Kulyk ◽  
Sergiy Dmitriev ◽  
Oleksandr Yakushenko ◽  
Oleksandr Popov
Keyword(s):  
Neural Network ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Training Data ◽  
Turbine Engines ◽  
Data Sets ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Wide Range ◽  
And Training

A method of obtaining test and training data sets has been developed. These sets are intended for training a static neural network to recognise individual and double defects in the air-gas path units of a gas-turbine engine. These data are obtained by using operational process parameters of the air-gas path of a bypass turbofan engine. The method allows sets that can project some changes in the technical conditions of a gas-turbine engine to be received, taking into account errors that occur in the measurement of the gas-dynamic parameters of the air-gas path. The operation of the engine in a wide range of modes should also be taken into account.

A Mean Line Prediction Method for Axial Flow Turbine Efficiency

1982 ◽  
Vol 104 (1) ◽  
pp. 111-119 ◽  
Author(s):  
S. C. Kacker ◽  
U. Okapuu
Keyword(s):  
Gas Turbine ◽  
Axial Flow ◽  
Prediction Method ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Loss System ◽  
Turbine Efficiency ◽  
Wide Range ◽  
Line Loss ◽  
Axial Turbines

A mean line loss system is described, capable of predicting the design point efficiencies of current axial turbines of gas turbine engines. This loss system is a development of the Ainley/Mathieson technique of 1951. The prediction method is tested against the “Smith’s chart” and against the known efficiencies of 33 turbines of recent design. It is shown to be able to predict the efficiencies of a wide range of axial turbines of conventional stage loadings to within ± 1 1/2 percent.

Computational Investigation on Centrifugal Compressor Performance at Various Altitudes

2011 ◽  
Vol 230-232 ◽  
pp. 1123-1128
Author(s):  
Yu Wang ◽  
Zhen Luo
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Cfd Simulation ◽  
Numerical Solutions ◽  
Weight Ratio ◽  
Critical Factor ◽  
Computational Method ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Ambient Temperatures

Small gas turbine engines have been considered as a potential and popular mean of propulsion for Unmanned Aerial Vehicles (UAV). With the advantage of high thrust/power-to-weight-ratio from these engines, small aircraft can have larger payload allowance and higher altitude capability. However, at present, these gas turbine engines are not mature enough to perform critical mission for UAV. To be used for such critical mission, these gas turbine engines need a better reliability, efficiency and endurance. The capability of the engine to work efficiently in conditions at different altitude with the variant of air density is a critical factor related to higher operational ceiling. Hence this work aims to present a Computational Fluid Dynamics (CFD) simulation approach focusing on centrifugal compressors which are applied to turbo machines. A computational method is developed for studying the performance of small gas turbine engines over a range of altitude and ambient temperatures under different engine rates, and a centrifugal compressor simulation model is generated by using CFD techniques. Through numerical solutions obtained for different mesh sets the finest mesh of the model was determined. The performance curves obtained by the CFD simulation has been compared with the results obtained from the analytical method.

scholarly journals Application of the vacuum casting technology in the production of small-size gas turbine engine blade machines

2021 ◽  
Vol 20 (3) ◽  
pp. 152-159
Author(s):  
A. M. Faramazyan ◽  
S. S. Remchukov ◽  
I. V. Demidyuk
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Gas Turbine Engine ◽  
Shrinkage Porosity ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Vacuum Casting ◽  
Turbine Engine ◽  
Design Values ◽  
The Cost

The application of casting technologies in the production of parts and assemblies of small-size gas turbine engines is justified in the paper. The technology of vacuum casting in gypsum molds was tested during the production of an experimental centrifugal compressor of a small-size gas turbine engine. On the basis of a 3D model of the designed centrifugal compressor, computational studies of vacuum casting were carried out and rational parameters of the technological process were determined. Prototypes of the developed centrifugal compressor of a small-size gas turbine engine were made. The results of calculations and the performed technological experiment confirmed the fill rate of the gating form and the absence of short pour. The distribution of shrinkage porosity and cavities corresponds to the design values and is concentrated in the central part of the casting that is subjected to subsequent machining. The area of the blades, disc and sleeve is formed without defects. The use of casting technologies in the production of parts and assemblies of small-size gas turbine engines assures the required quality with a comparatively low price of the finished product, making it possible to achieve the balance between the cost of the technology and the quality of the product made according to this technology.

scholarly journals ВПЛИВ ГУСТОТИ РЕШІТКИ НА АЕРОДИНАМІЧНУ НАВАНТАЖЕНІСТЬ РОБОЧОГО КОЛЕСА ОСЬОВОГО ВЕНТИЛЯТОРА

2020 ◽  
pp. 38-43
Author(s):  
Екатерина Викторовна Дорошенко ◽  
Михаил Владимирович Хижняк ◽  
Юрий Матвеевич Терещенко
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Average Radius ◽  
Gas Turbine Engines ◽  
Axial Fan ◽  
Aerodynamic Loading ◽  
Wide Range ◽  
Axial Fans ◽  
Bypass Ratio

The main requirements that apply to axial fans and axial compressors of aircraft gas turbine engines include minimum dimensions and weight; high aerodynamic load; high coefficient of performance; wide range of steady work; high reliability. For gas turbine engines, the requirements of minimum weight and dimensions are especially important, since the engines must provide flights at high velocities and altitudes. This study aims to assess the effect of the solidity of the impeller fan on the average radius on the aerodynamic loading of the impeller of an axial fan for an engine with a high bypass ratio. The object of the study is the impeller of the fan. The solidity of the impeller fan on the average radius varied in the range from 1.8 to 0.82, the number of blades of the impeller fan varied from 33 to 15, respectively. The studies in this work were carried out by the method of numerical experiment. The flow in the axial fans was simulated by solving the system of Navier-Stokes equations, which were closed by the SST turbulent viscosity model. Based on the analysis of the results of the study, an assessment is made of the influence of the solidity of the impeller fan at an average radius on the aerodynamic loading of the impeller of an axial fan for an engine with a high bypass ratio. The research results showed that with a decrease in the solidity of the impeller fan at an average radius of 1.8 to 0.82 in operating modes with an axial inlet velocity of 80 to 120 m / s, the impeller fan pressure ratio decreases by 0.11 ... 3.2 %. The maximum decrease in the fan pressure ratio increase for the fan impeller with the parameters studied is 3.2 %, with a decrease in the number of fan blades from 33 to 15, while the total weight of the blades decreases by 54.55 %. The decrease in the solidity on the average radius of the impeller of the studied fan leads to a decrease in the relative sizes of the low-velocity zones at the sleeve and on the periphery and to a decrease in the level of flow unevenness. A further reduction in the level of flow non-uniformity behind the fan is possible when using the boundary layer control in the fan - this is the task of subsequent studies.

scholarly journals МЕТОД РАСЧЕТА ТЕРМОГАЗОДИНАМИЧЕСКИХ ПАРАМЕТРОВ ТУРБОВАЛЬНОГО ГТД НА ОСНОВЕ ПОВЕНЦОВОГО ОПИСАНИЯ ЛОПАТОЧНЫХ МАШИН. ЧАСТЬ 1. ОСНОВНЫЕ УРАВНЕНИЯ

2018 ◽  
pp. 48-58
Author(s):  
Людмила Георгиевна Бойко ◽  
Олег Владимирович Кислов ◽  
Наталия Владимировна Пижанкова
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Geometrical Parameters ◽  
Gas Turbine Engines ◽  
Balance Equations ◽  
Wide Range ◽  
In Series ◽  
Multistage Compressor

Gas turbine engines processes mathematic simulations are widely used in different steps of its living cycle. All engine simulations may be divided into different difficulty levels: higher simulation level allows doing a more pre­cise description of physical processes in main units of gas turbine engines and their elements. It gives the oppor­tunity for getting better arrangement of calculation results and experimental data, reduce the quality of factors, which are traditionally used in determine engine operational characteristics with 1-level models.The purpose of the article is to describe the thermogasdynamic parameters and maintenance perfomances cal­culation method, which based on second level mathematic simulation. Its main feature is blade-to-blade turbomachines description (multistage compressor and multistage cooling gas turbine), which allows to take into account blade and flow path geometrical parameters. Their changing during the gas turbine engine design and de­velopment processes influence its performances: thrust, fuel consumption, efficiency as functions of values of flow rate, rotational speed, engine entrance conditions and so on. All these dependences could be defined by using proposed calculation method.In distinction from methods which are noted, this method allows to concede compressor or turbine incidence angles, drag values, pressure ratio, surge margin in design and off-design  engine regimes. The opportunity to take into account by-passing and air bleeding from compressor blade channels and their engine parameters influence is very important also.The article includes calculation method main points, block-scheme, equations system, which gives the opportunity of alignment the engine units and their elements in wide range of state working regimes. Set of equations consists of flow rate balance equations through the stages of multistage compressor and turbine, combustion chamber and connected channels. Also system includes power balance equations, by-passing, air bleeding from compressor stages channels, its admission into the cooling turbine stages and ac­counts their thermodynamic parameters. Compressors and turbines maps parameters are calculated with main turbomachinery theory lows and semi-empirical dependences.This article is the first in series of articles, which considers this problem

scholarly journals Ceramic Bearings for Use in Gas Turbine Engines

1989 ◽  
Vol 111 (1) ◽  
pp. 146-154 ◽  
Author(s):  
E. V. Zaretsky
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Wide Range ◽  
Rolling Element ◽  
Full Complement ◽  
Endurance Tests ◽  
Bearing Design ◽  
Government Laboratories

Three decades of research by U.S. industry and government laboratories have produced a vast array of data related to the use of ceramic rolling-element bearings and bearing components for aircraft gas turbine engines. Materials such as alumina, silicon carbide, titanium carbide, silicon nitride, and a crystallized glass ceramic have been investigated. Rolling-element endurance tests and analysis of full-complement bearings have been performed. Materials and bearing design methods have improved continuously over the years. This paper reviews a wide range of data and analyses with emphasis on how early NASA contributions as well as more recent data can enable the engineer or metallurgist to determine just where ceramic bearings are most applicable for gas turbines.

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