Pub Date : 2019-11-08DOI: 10.32743/2658-4077.2019.8.8.175
Gleb Sincov, Grigoriy Jarkov
This article is devoted to the analysis of the goals and principles of the formation of a parliamentary control system in the Russian Federation. The main problems related to achieving the goals of the control activities of the federal legislative bodies in modern Russia are also covered in this article. The major solution of exciting problems on social representation development seems to be rooted in an approach to eliminate formalism in implementing the concept of separation of powers in Russia. Ключевые слова: парламент, парламентский контроль, разделение властей, законность, права человека, народовластие, демократия, правовой мониторинг.
{"title":"LEGAL NATURE OF PARLIAMENTARY CONTROL IN THE RUSSIAN FEDERATION","authors":"Gleb Sincov, Grigoriy Jarkov","doi":"10.32743/2658-4077.2019.8.8.175","DOIUrl":"https://doi.org/10.32743/2658-4077.2019.8.8.175","url":null,"abstract":"This article is devoted to the analysis of the goals and principles of the formation of a parliamentary control system in the Russian Federation. The main problems related to achieving the goals of the control activities of the federal legislative bodies in modern Russia are also covered in this article. The major solution of exciting problems on social representation development seems to be rooted in an approach to eliminate formalism in implementing the concept of separation of powers in Russia. Ключевые слова: парламент, парламентский контроль, разделение властей, законность, права человека, народовластие, демократия, правовой мониторинг.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"48 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85121985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-08DOI: 10.32743/2658-4077.2019.7.7.159
Yuri Kolin
In the article aspects of the impact of positive discrimination models on the level of vertical social mobility and prospects for economic growth have been analyzed. The necessity of creating and broad programs distribution of positive discrimination as an incentive for social integration and economic growth is substantiated. The relevance of the problem of applying positive discrimination models lies in their influence on the level of vertical social mobility, reduction of social polarization and economic growth in conditions of increasing trends in social polarization in the modern world. The goal of research is to analyze the impact of positive discrimination on flexibility, the level of vertical social mobility and the adaptive potential of the social system, and prospects for economic growth. No 7 (7), октябрь, 2019 г. The research methodology is based on a comparative analysis of social characteristics and economic growth rates of societies that demonstrate high and low levels of social inequality and vertical social mobility. As a theoretical basis, the results of studies on the correlation of social inequality and the level of vertical social mobility are analyzed including the context of intergenerational social dynamics, as well as historical experience with the use of positive discrimination models. The growing importance of positive discrimination is justified to reduce social inequality, to develop social integration and to strengthen vertical social mobility. The insufficient level of attention of researchers and government institutions to the problem of positive discrimination as a factor of reducing social polarization, enhancing the flexibility and diversity of the social system and accelerating economic growth is determined. The research novelty lies in the analysis of the positive discrimination policy as a factor in reducing social polarization, enhancing the flexibility and diversity of the social system and stimulating economic growth. Ключевые слова: социальное неравенство, социальная поляризация, общественная интеграция, инклюзивное общество, постматериалистические ценности, человеческий капитал, постиндустриальное общество, позитивная дискриминация, вертикальная социальная мобильность.
{"title":"POSITIVE DISCRIMINATION AS A FACTOR OF LIMITATION OF SOCIAL POLARIZATION AND STIMULUS TO ECONOMIC GROWTH (IN THE CONTEXT OF THE DISCUSSION ON PROSPECTS AFFIRMATIVE ACTION)","authors":"Yuri Kolin","doi":"10.32743/2658-4077.2019.7.7.159","DOIUrl":"https://doi.org/10.32743/2658-4077.2019.7.7.159","url":null,"abstract":"In the article aspects of the impact of positive discrimination models on the level of vertical social mobility and prospects for economic growth have been analyzed. The necessity of creating and broad programs distribution of positive discrimination as an incentive for social integration and economic growth is substantiated. The relevance of the problem of applying positive discrimination models lies in their influence on the level of vertical social mobility, reduction of social polarization and economic growth in conditions of increasing trends in social polarization in the modern world. The goal of research is to analyze the impact of positive discrimination on flexibility, the level of vertical social mobility and the adaptive potential of the social system, and prospects for economic growth. No 7 (7), октябрь, 2019 г. The research methodology is based on a comparative analysis of social characteristics and economic growth rates of societies that demonstrate high and low levels of social inequality and vertical social mobility. As a theoretical basis, the results of studies on the correlation of social inequality and the level of vertical social mobility are analyzed including the context of intergenerational social dynamics, as well as historical experience with the use of positive discrimination models. The growing importance of positive discrimination is justified to reduce social inequality, to develop social integration and to strengthen vertical social mobility. The insufficient level of attention of researchers and government institutions to the problem of positive discrimination as a factor of reducing social polarization, enhancing the flexibility and diversity of the social system and accelerating economic growth is determined. The research novelty lies in the analysis of the positive discrimination policy as a factor in reducing social polarization, enhancing the flexibility and diversity of the social system and stimulating economic growth. Ключевые слова: социальное неравенство, социальная поляризация, общественная интеграция, инклюзивное общество, постматериалистические ценности, человеческий капитал, постиндустриальное общество, позитивная дискриминация, вертикальная социальная мобильность.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"79 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83793693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-08DOI: 10.32743/2658-4077.2019.7.7.160
V. Rodachin
The article substantiates the need to include in the unified state system of monitoring manifestations of religious and nationalist extremism as well as manifestations of political extremism, officially referred to the main threats of extremism in the Russian Federation. The author has developed and proposed criteria for assessing the manifestations of political extremism. Ключевые слова: политический экстремизм, протестная активность, мониторинг проявлений экстремизма, критерии оценки политического экстремизма.
{"title":"SIGNS OF ACTUALIZATION OF POLITICAL EXTREMISM AS A THREAT TO RUSSIA'S NATIONAL SECURITY","authors":"V. Rodachin","doi":"10.32743/2658-4077.2019.7.7.160","DOIUrl":"https://doi.org/10.32743/2658-4077.2019.7.7.160","url":null,"abstract":"The article substantiates the need to include in the unified state system of monitoring manifestations of religious and nationalist extremism as well as manifestations of political extremism, officially referred to the main threats of extremism in the Russian Federation. The author has developed and proposed criteria for assessing the manifestations of political extremism. Ключевые слова: политический экстремизм, протестная активность, мониторинг проявлений экстремизма, критерии оценки политического экстремизма.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"11 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72394118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper details an experimental investigation, using a linear cascade, into the effects of real geometry features on the aerodynamic performance of stator blade rows within axial flow compressors. The specific geometric features investigated include shroud cavities, inter-platform gaps, vane-pack gaps and the effects of misalignment of the platform endwalls due to manufacturing tolerances. A computational investigation into these effects is also included. To ensure that the linear cascade measurements are representative of a multi-stage compressor environment a novel experimental technique was developed to generate a hub endwall boundary layer which had skew. The boundary layer skew generation method involves injecting flow along the cascade endwall in such a manner as to control both the displacement thickness and tangential momentum thickness of the resulting boundary layer. Without the presence of the endwall boundary layer skew the linear cascade could not reproduce the flow features typically observed in a multi-stage compressor. The investigation reveals that real geometry features can have a significant impact on the flowfield within a blade passage. For a shrouded stator, increasing the leakage flow rate increases the stagnation pressure loss coefficient. However, high levels of whirl pickup of the leakage flow as it passes through the stator-shroud cavity can offset the natural secondary flow within the stator passage and thus reduce the stagnation pressure loss. All of the steps and gaps that were observed to be present in real compressors were found to increase the stagnation pressure loss relative to that of a smooth endwall. It is also shown that the computational method is capable of capturing the trends observed in the experiments.
{"title":"Effects of Stator Platform Geometry Features on Blade Row Performance","authors":"D. J. Taylor, J. Longley","doi":"10.33737/JGPPS/111508","DOIUrl":"https://doi.org/10.33737/JGPPS/111508","url":null,"abstract":"This paper details an experimental investigation, using a linear cascade, into the effects of real geometry features on the aerodynamic performance of stator blade rows within axial flow compressors. The specific geometric features investigated include shroud cavities, inter-platform gaps, vane-pack gaps and the effects of misalignment of the platform endwalls due to manufacturing tolerances. A computational investigation into these effects is also included. \u0000To ensure that the linear cascade measurements are representative of a multi-stage compressor environment a novel experimental technique was developed to generate a hub endwall boundary layer which had skew. The boundary layer skew generation method involves injecting flow along the cascade endwall in such a manner as to control both the displacement thickness and tangential momentum thickness of the resulting boundary layer. Without the presence of the endwall boundary layer skew the linear cascade could not reproduce the flow features typically observed in a multi-stage compressor. \u0000The investigation reveals that real geometry features can have a significant impact on the flowfield within a blade passage. For a shrouded stator, increasing the leakage flow rate increases the stagnation pressure loss coefficient. However, high levels of whirl pickup of the leakage flow as it passes through the stator-shroud cavity can offset the natural secondary flow within the stator passage and thus reduce the stagnation pressure loss. All of the steps and gaps that were observed to be present in real compressors were found to increase the stagnation pressure loss relative to that of a smooth endwall. It is also shown that the computational method is capable of capturing the trends observed in the experiments.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45360653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes an upgrade to high temperature operation of the Engine Component AeroThermal (ECAT) facility, an established engine-parts facility at the University of Oxford. The facility is used for high-TRL research and development, new technology demonstration, and for component validation (typically large civil-engine HP NGVs). In current operation the facility allows Reynolds number, Mach number, and coolant-to-mainstream pressure ratio to be matched to engine conditions. Rich-burn or lean-burn temperature, swirl and turbulence profiles can also be simulated. The upgrade will increase the maximum inlet temperature to 600 K, allowing coolant-to-mainstream temperature ratio to be matched to engine conditions. This will allow direct validation of temperature ratio scaling methods in addition to providing a test bed in which all important non-dimensional parameters for aero-thermal behaviour are exactly matched. To accurately predict the operating conditions of the upgraded facility, a low order transient thermal model was developed in which the air delivery system and working section are modelled as a series of distributed thermal masses. Nusselt number correlations were used to calculate convective heat transfer to and from the fluid in the pipes and working section. The correlation was tuned and validated with experimental results taken from tests conducted in the existing facility. This modelling exercise informed a number of high-level facility design decisions, and provides an accurate estimate of the running conditions of the upgraded facility. We present detailed results from the low-order modelling, and discuss the key design decisions. We also present a discussion of challenges in the mechanical design of the working section, which is complicated by transient thermal stress induced in the working section components during facility start-up. The high-temperature core is unusually high-TRL for a research organisation, and we hope both the development and methodology will be of interest to engine designers and the research community.
{"title":"Calibrated Low-Order Transient Thermal and Flow Models for Robust Test Facility Design","authors":"Andrew Messenger, T. Povey","doi":"10.33737/jgpps/122270","DOIUrl":"https://doi.org/10.33737/jgpps/122270","url":null,"abstract":"This paper describes an upgrade to high temperature operation of the Engine Component AeroThermal (ECAT) facility, an established engine-parts facility at the University of Oxford. The facility is used for high-TRL research and development, new technology demonstration, and for component validation (typically large civil-engine HP NGVs). In current operation the facility allows Reynolds number, Mach number, and coolant-to-mainstream pressure ratio to be matched to engine conditions. Rich-burn or lean-burn temperature, swirl and turbulence profiles can also be simulated. The upgrade will increase the maximum inlet temperature to 600 K, allowing coolant-to-mainstream temperature ratio to be matched to engine conditions. This will allow direct validation of temperature ratio scaling methods in addition to providing a test bed in which all important non-dimensional parameters for aero-thermal behaviour are exactly matched.\u0000To accurately predict the operating conditions of the upgraded facility, a low order transient thermal model was developed in which the air delivery system and working section are modelled as a series of distributed thermal masses. Nusselt number correlations were used to calculate convective heat transfer to and from the fluid in the pipes and working section. The correlation was tuned and validated with experimental results taken from tests conducted in the existing facility. This modelling exercise informed a number of high-level facility design decisions, and provides an accurate estimate of the running conditions of the upgraded facility. We present detailed results from the low-order modelling, and discuss the key design decisions. We also present a discussion of challenges in the mechanical design of the working section, which is complicated by transient thermal stress induced in the working section components during facility start-up. The high-temperature core is unusually high-TRL for a research organisation, and we hope both the development and methodology will be of interest to engine designers and the research community.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47882230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Philip Reggentin, J. Friedrichs, J. Flegler, I. McBean
Due to the increasing demand towards flexible operation of conventional power plants also the seals of their turbines have to adapt to varying loads. Based on the basic design of a clamped brush seal, a novel seal with a pressure-actuated backplate is introduced which is capable of combining the advantages of low and high inclined brush seals while avoiding their undesired properties for flexible operation. During preliminary investigations on a test rig operated with compressed air and without rotation, the functionality of the improved design was demonstrated. It is shown that the leakage mass flow was lowered by up to 40% while undesired bristle oscillations were reduced by up to 90% at low pressure differences compared to conventional seal designs. After the adaption of the design for subsequent investigations under realistic conditions comparable to those in a steam turbine, further tests were conducted at TU Braunschweig´s hot steam test rig. Within these investigations the novel design showed improved properties regarding a high leakage performance and an advanced capability to avoid deterioration due to shaft excursions compared to brush seals with fixed backplate design.
{"title":"INVESTIGATION OF A NOVEL PRESSURE-ACTUATED BRUSH SEAL UNDER HOT STEAM CONDITIONS","authors":"Philip Reggentin, J. Friedrichs, J. Flegler, I. McBean","doi":"10.33737/gpps19-bj-119","DOIUrl":"https://doi.org/10.33737/gpps19-bj-119","url":null,"abstract":"Due to the increasing demand towards flexible operation of conventional power plants also the seals of their turbines have to adapt to varying loads. Based on the basic design of a clamped brush seal, a novel seal with a pressure-actuated backplate is introduced which is capable of combining the advantages of low and high inclined brush seals while avoiding their undesired properties for flexible operation. During preliminary investigations on a test rig operated with compressed air and without rotation, the functionality of the improved design was demonstrated. It is shown that the leakage mass flow was lowered by up to 40% while undesired bristle oscillations were reduced by up to 90% at low pressure differences compared to conventional seal designs. After the adaption of the design for subsequent investigations under realistic conditions comparable to those in a steam turbine, further tests were conducted at TU Braunschweig´s hot steam test rig. Within these investigations the novel design showed improved properties regarding a high leakage performance and an advanced capability to avoid deterioration due to shaft excursions compared to brush seals with fixed backplate design.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46791573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Oettinger, Dajan Mimic, M. Henke, Oleg Schmunk, J. Seume
The aim of this work is the decomposition, quantification, and analysis of losses related to the axial-gap size effect. Both experimental data and unsteady RANS calculations are investigated for axial gaps equal to 20%, 50% and 80% of the stator axial chord. A framework for identifying sources of loss typical in turbomachinery is derived and utilized for the low-pressure turbine presented. The analysis focuses on the dependency of these losses on the axial-gap variation. It is found that two-dimensional profile losses increase for smaller gaps due to higher wake-mixing losses and unsteady wake-blade interaction. Losses in the end-wall regions, however, decrease for smaller gaps. The total system efficiency can be described by a superposition of individual loss contributions, the optimum of which is found for the smallest gap investigated. It is concluded that these loss contributions are characteristic for the medium aspect-ratio airfoils and operating conditions investigated. This establishes a deeper physical understanding for future investigations into the axial-gap size effect and its interdependency with other design parameters.
{"title":"Loss Assessment of the Axial-Gap Size Effect in a Low-Pressure Turbine","authors":"M. Oettinger, Dajan Mimic, M. Henke, Oleg Schmunk, J. Seume","doi":"10.33737/gpps19-bj-207","DOIUrl":"https://doi.org/10.33737/gpps19-bj-207","url":null,"abstract":"The aim of this work is the decomposition, quantification, and analysis of losses related to the axial-gap size effect. Both experimental data and unsteady RANS calculations are investigated for axial gaps equal to 20%, 50% and 80% of the stator axial chord. A framework for identifying sources of loss typical in turbomachinery is derived and utilized for the low-pressure turbine presented. The analysis focuses on the dependency of these losses on the axial-gap variation. It is found that two-dimensional profile losses increase for smaller gaps due to higher wake-mixing losses and unsteady wake-blade interaction. Losses in the end-wall regions, however, decrease for smaller gaps. The total system efficiency can be described by a superposition of individual loss contributions, the optimum of which is found for the smallest gap investigated.\u0000\u0000It is concluded that these loss contributions are characteristic for the medium aspect-ratio airfoils and operating conditions investigated. This establishes a deeper physical understanding for future investigations into the axial-gap size effect and its interdependency with other design parameters.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41450630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As technology advances, rotating machinery are operating at higher rotational speeds and increased pressures with greater heat concentration (i.e. smaller and hotter). This combination of factors increases structural stresses, while increasing the risk of exceeding temperature limits of components. To reduce stresses and protect components, it is necessary to have accurately designed thermal management systems with well-understood heat transfer characteristics. Currently, available heat transfer correlations operating within high Taylor number (above 1×10^10) flow regimes are lacking. In this work, the design of a high Taylor number flow experimental test rig is presented. A non-invasive methodology, used to capture the instantaneous heat flux of the rotating body, is also presented. Capability of the test rig, in conjunction with the use of high-density fluids, increases the maximum Taylor number beyond that of previous works. Data of two experiments are presented. The first, using air, with an operating Taylor number of 8.8± 0.8 ×10^7 and an effective Reynolds number of 4.2± 0.5 ×10^3, corresponds to a measured heat transfer coefficient of 1.67 ± 0.9 ×10^2 W/m2K and Nusselt number of 5.4± 1.5×10^1. The second, using supercritical carbon dioxide, demonstrates Taylor numbers achievable within the test rig of 1.32±0.8×10^12. A new correlation using air, with operating Taylor numbers between 7.4×10^6 and 8.9×10^8 is provided, comparing favourably with existing correlations within this operating range. A unique and systematic approach for evaluating the uncertainties is also presented, using the Monte-Carlo method.
{"title":"Taylor-Couette-Poiseuille flow heat transfer in a high Taylor number test rig","authors":"P. Swann, Hugh Russell, I. Jahn","doi":"10.33737/jgpps/140252","DOIUrl":"https://doi.org/10.33737/jgpps/140252","url":null,"abstract":"As technology advances, rotating machinery are operating at higher rotational speeds and increased pressures with greater heat concentration (i.e. smaller and hotter). This combination of factors increases structural stresses, while increasing the risk of exceeding temperature limits of components. To reduce stresses and protect components, it is necessary to have accurately designed thermal management systems with well-understood heat transfer characteristics. Currently, available heat transfer correlations operating within high Taylor number (above 1×10^10) flow regimes are lacking. In this work, the design of a high Taylor number flow experimental test rig is presented. A non-invasive methodology, used to capture the instantaneous heat flux of the rotating body, is also presented. Capability of the test rig, in conjunction with the use of high-density fluids, increases the maximum Taylor number beyond that of previous works. Data of two experiments are presented. The first, using air, with an operating Taylor number of 8.8± 0.8 ×10^7 and an effective Reynolds number of 4.2± 0.5 ×10^3, corresponds to a measured heat transfer coefficient of 1.67 ± 0.9 ×10^2 W/m2K and Nusselt number of 5.4± 1.5×10^1. The second, using supercritical carbon dioxide, demonstrates Taylor numbers achievable within the test rig of 1.32±0.8×10^12. A new correlation using air, with operating Taylor numbers between 7.4×10^6 and 8.9×10^8 is provided, comparing favourably with existing correlations within this operating range. A unique and systematic approach for evaluating the uncertainties is also presented, using the Monte-Carlo method.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49525411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Johannes Altmeppen, Heike Sommerfeld, C. Koch, S. Staudacher
Atmospheric air is always contaminated by liquid or solid particles of different size, concentration and chemical composition. This leads to performance degradation during the operation of stationary or flying gas turbines. Erosion and the deposition of particles along the flow path are of particular importance. Multiple numerical studies investigated the influences of these phenomena. However, the basic challenge of modelling the particle wall interaction and its data spread with sufficient accuracy remains. In this work a model that estimates the statistical spread of rebound data due to target surface roughness through analytical considerations is presented. The model predicts the local impact angle of an individual particle by evaluating how deep a particle can theoretically penetrate the target surface with respect to its size. Based on roughness profiles which have been found to be characteristic for performance deterioration in compressor application a sensitivity study is conducted. A dimensionless roughness parameter Φ_R was found that characterizes the effect of target surface roughness on rebound spread data. The spread model is connected with a quasi-physical model, to evaluate the effect of surface roughness for a particle’s individual rebound behaviour. The synthesized data is discussed by taking into account measurement data reported in literature.
{"title":"An Analytical Approach to Estimate the Effect of Surface Roughness on Particle Rebound","authors":"Johannes Altmeppen, Heike Sommerfeld, C. Koch, S. Staudacher","doi":"10.33737/gpps19-bj-099","DOIUrl":"https://doi.org/10.33737/gpps19-bj-099","url":null,"abstract":"Atmospheric air is always contaminated by liquid or solid particles of different size, concentration and chemical composition. This leads to performance degradation during the operation of stationary or flying gas turbines. Erosion and the deposition of particles along the flow path are of particular importance. Multiple numerical studies investigated the influences of these phenomena. However, the basic challenge of modelling the particle wall interaction and its data spread with sufficient accuracy remains.\u0000In this work a model that estimates the statistical spread of rebound data due to target surface roughness through analytical considerations is presented. The model predicts the local impact angle of an individual particle by evaluating how deep a particle can theoretically penetrate the target surface with respect to its size. Based on roughness profiles which have been found to be characteristic for performance deterioration in compressor application a sensitivity study is conducted. A dimensionless roughness parameter Φ_R was found that characterizes the effect of target surface roughness on rebound spread data. The spread model is connected with a quasi-physical model, to evaluate the effect of surface roughness for a particle’s individual rebound behaviour. The synthesized data is discussed by taking into account measurement data reported in literature.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48551301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-08DOI: 10.32743/2658-4077.2019.5.5.129
A. Andreev
{"title":"ACTIVE CITIZENSHIP OF YOUNG PEOPLE (THE RESULTS OF A POLL)","authors":"A. Andreev","doi":"10.32743/2658-4077.2019.5.5.129","DOIUrl":"https://doi.org/10.32743/2658-4077.2019.5.5.129","url":null,"abstract":"","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"83 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88523055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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