scholarly journals ПІДХІД НЕЧІТКОЇ КЛАСТЕРИЗАЦІЇ В РОЗПОДІЛЕНИХ ІНФОРМАЦІЙНИХ СИСТЕМАХ АВІАЦІЙНИХ ДВИГУНІВ

2020 ◽  
pp. 113-117
Author(s):  
Сергій Сергійович Товкач

The article is devoted to the development of systematic approaches for the construction of a distributed information system (DIS) of aviation gas turbine engines (GTE). It is determined that the use of CALS-technologies (Continuous Acquisition and Life-Cycle Support), which should ensure the competitiveness of products on the world market, is essential for the integration of the aircraft engine industry into the world community of developers and manufacturers. The relevance of the use of CALS-technologies is due to the fact that today, in accordance with market requirements, the world's leading companies have set deadlines for the creation of a new design of the civil aviation engine of the fifth and sixth generations. The block-modular principle of engine construction - mathematical models and software - with the satisfaction of the criteria of divergence, transformation, and convergence has been considered. For a simplified search of the optimal technology for building a distributed information system of an aviation engine, the use of a fuzzy clustering approach is proposed, which is a design method with finding new knowledge about the gas turbine engine with highly efficient performance. By identifying methods of knowledge analysis and basic methods of clustering, that are K-means, graph clustering algorithms, algorithms of the FOREL family, hierarchical clustering, Kohonen neural network, algorithms of the KRAB family, fuzzy mean algorithms, subtractive, the application clustering in distributed information systems of aviation engines have been determined. For the convenient implementation of the defined method, a set of data objects of the GTE information system, which are contained in the experimental files, are considered. According to the results of the fuzzy clustering procedure, the coordinates of the class centers, the belonging of each data set to the classes, the values of the objective function, which have an approximate character, and are used for preliminary structuring of the data, are fixed. After research, it was determined that the integration of clustering algorithms should help build a more accurate model of the gas turbine engine and increase its speed.

Author(s):  
David M. Walters ◽  
Yura A. Sevcenco ◽  
Andrew P. Crayford ◽  
Richard Marsh ◽  
Philip J. Bowen ◽  
...  

This paper presents particulate matter (PM) size spectral measurements, analysed to determine number and mass concentration, taken using a fast response differential mobility spectrometer (DMS500). Exhaust samples from multiple commercially available large civil aviation gas turbine engines and an auxiliary power unit operating at high and low engine power conditions were studied, in addition to a simulated aviation gas turbine exhaust, which was operated to exhibit specific PM output. Results show all exhaust sources as having similar bi-modal PM size spectra with both number and mass concentrations highly dependent on the emission source and the sampling testing condition. When operating at high power levels all of the tested gas turbine emission sources, with the exception of the 2-stage combustor design, generally produced distributions of PM which exhibited larger average mean diameter particle sizes and higher number and mass concentrations.


Author(s):  
Kenneth L. Suder

Abstract Given the maturity of the gas turbine engine since its invention and also considering the limited and flattened level of resources expected to be allocated for NASA aeronautics research and development, we ask the question are NASA technology investments still needed to enable future turbine engine-based propulsion systems? If so, what is NASA’s unique role to justify NASA’s investment? To address this topic, we will first review the accomplishments and the impact that NASA Glenn Research Center has made on turbine engine technologies over the last 78 years. Specifically, this paper discusses NASA’s role and contributions to turbine engine development, specific to both 1) NASA’s role in conducting experiments to understand flow physics and provide relevant benchmark validation experiments for Computational Fluid Dynamics (CFD) code development, validation, and assessment; and 2) the impact of technologies resulting from NASA collaborations with industry, academia, and other government agencies. Note that the scope of the discussion is limited to the NASA technology contributions with which the author was intimately associated, and does not represent the entirety of the NASA contributions to turbine engine technology. The specific research, development, and demonstrations discussed herein were selected to both 1) provide a comprehensive review and reference list of the technology and its impact, and 2) identify NASA’s unique role and highlight how NASA’s involvement resulted in additional benefit to the gas turbine engine community. Secondly, we will discuss current NASA collaborations that are in progress and provide a status of the results. Finally, we discuss the challenges anticipated for future turbine engine-based propulsion systems for civil aviation and identify potential opportunities for collaboration where NASA involvement would be beneficial. Ultimately, the gas turbine engine community will decide if NASA involvement is needed to contribute to the development of the design and analysis tools, databases, and technology demonstration programs to meet these challenges for future turbine engine-based propulsion systems.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Kenneth L. Suder

Abstract Given the maturity of the gas turbine engine since its invention and considering the limited resources expected to be allocated for NASA aeronautics research and development, we ask the question are NASA technology investments still needed to enable future turbine engine-based propulsion systems? If so, what is NASA's unique role to justify NASA's investment? To address this topic, we first summarize NASA's role and contributions to turbine engine development, specific to both (1) NASA's role in conducting experiments to understand flow physics and provide relevant benchmark validation experiments for computational fluid dynamics (CFD) code development, validation, and assessment and (2) the impact of technologies resulting from NASA collaborations with industry, academia, and other government agencies. Note that the scope of the discussion is limited to the NASA technology contributions with which the author was intimately associated and does not represent the entirety of the NASA contributions to turbine engine technology. The specific research, development, and demonstrations discussed herein were selected to both (1) provide a comprehensive review and reference list of the technology and its impact and (2) identify NASA's unique role and highlight how NASA's involvement resulted in additional benefit to the gas turbine engine community. Second, we will discuss current NASA collaborations that are in progress and provide a status of the results. Finally, we discuss the challenges anticipated for future turbine engine-based propulsion systems for civil aviation and identify potential opportunities for collaboration where NASA involvement would be beneficial.


2019 ◽  
Vol 22 (6) ◽  
pp. 8-16
Author(s):  
Sh. Ardeshiri

The current development trend of global civil aviation is the growth of passenger and freight traffic, which entails the consumption of jet fuel. Under these conditions, increasing the efficiency of jet fuel used is of great importance. Global energy consumption is constantly growing, and, first of all, the question of diversification of oil resources arises, resources from which the bulk of motor fuels is produced. Other types of raw energy sources (natural gas, coal, bio-mass) currently account for only a small part. However, an analysis of the development of jet fuels indicates that work is underway to obtain these from other sources of raw materials, especially bio-fuels. Much attention is given to obtaining bio-fuels from renewable sources – such as algae. The issue of the mass transition of civil aviation to alternative fuels is complex and requires the solution of intricate technical as well as economic issues. One of these is the assessment of the impact of new fuels on GTE performance. It is important to give an objective and quick assessment of the use of various types of fuels on the main characteristics of the engine – i.e., throttle and high-speed characteristics. In this case, it is necessary to take into account chemical processes in the chemical composition of new types of fuel. To assess the effect of fuels on the characteristics of a gas turbine engine, it is proposed to use a mathematical model that would take into account the main characteristics of the fuel itself. Therefore, the work proposes a mathematical model for calculating the characteristics of a gas turbine engine taking into account changes in the properties of the fuel itself. A comparison is made of the percentage of a mixture of biofuels and JetA1 kerosene, as well as pure JetA1 and TC-1 kerosene. The calculations, according to the proposed model, are consistent with the obtained characteristics of a gas turbine engine in operation when using JetA1 and TC-1 kerosene. Especially valuable are the obtained characteristics of a gas turbine engine depending on a mixture of biofuel and kerosene. It was found that a mixture of biofuel and kerosene changes the physicochemical characteristics of fuel and affects the change in engine thrust and specific fuel consumption. It is shown that depending on the obtained physicochemical properties of a mixture of biofuel and kerosene, it is possible to increase the fuel efficiency and environmental friendliness of the gas turbine engines used.


1992 ◽  
Author(s):  
KIRK D ◽  
ANDREW VAVRECK ◽  
ERIC LITTLE ◽  
LESLIE JOHNSON ◽  
BRETT SAYLOR

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