Structures such as fuselage, blade and wing in aeronautical and astronautical engineering are often subjected to cyclic loads in their service life, which in turn causes breathing cracks in these structures. To provide much more precise position of breathing cracks in structures and avoid structure failure, a local vibration-based approach using transmissibility function-based features is proposed and verified in this study. In the new method, nonlinear dynamic behaviour of cracked structures is simulated by a chain-type multiple-degree-of-freedom (MDOF) model, in which breathing cracks are represented as related nonlinear connections between masses. By modifying local structural physical parameters (mass, stiffness or damping coefficient), transmissibility function-based features are derived from cracked structures only and corresponding damage indicator is calculated for fault localization. Based on results of simulations on the chain-type model with breathing cracks, the effectiveness and practicability of damage indicator and method are verified and demonstrated. Moreover, merits, drawbacks and further development of this method are summarized and discussed.
{"title":"Localization of breathing cracks in engineering structures with transmissibility function-based features","authors":"Quankun Li, Zihao Li, Mingfu Liao, Kang Zhang","doi":"10.33737/jgpps/150489","DOIUrl":"https://doi.org/10.33737/jgpps/150489","url":null,"abstract":"Structures such as fuselage, blade and wing in aeronautical and astronautical engineering are often subjected to cyclic loads in their service life, which in turn causes breathing cracks in these structures. To provide much more precise position of breathing cracks in structures and avoid structure failure, a local vibration-based approach using transmissibility function-based features is proposed and verified in this study. In the new method, nonlinear dynamic behaviour of cracked structures is simulated by a chain-type multiple-degree-of-freedom (MDOF) model, in which breathing cracks are represented as related nonlinear connections between masses. By modifying local structural physical parameters (mass, stiffness or damping coefficient), transmissibility function-based features are derived from cracked structures only and corresponding damage indicator is calculated for fault localization. Based on results of simulations on the chain-type model with breathing cracks, the effectiveness and practicability of damage indicator and method are verified and demonstrated. Moreover, merits, drawbacks and further development of this method are summarized and discussed.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44705238","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}
Hybrid-electric commuter aircraft segment is playing a significant role in the electrification of air transportation. Towards the achievement of efficient and robust transportation, design and optimization processes are necessary to evaluate the different aircraft components. Within this context, the current work investigates the impact of the positioning of the propulsion system and spars on the structural integrity of a hybrid-electric commuter aircraft. The proposed approach is based on an in-house aircraft sizing tool, along with geometry generation and high-fidelity structural evaluation models. These tools are tailored in an automated computational pipeline, that includes pre-processing, model evaluation and post-processing tasks, able to perform design space exploration and optimization over different loading conditions of a selected mission envelope. This work focuses on the assessment of the impact of the additional non-structural weight e.g., batteries, fuel, and propulsion components, inside the wing box, on the stress, deformation and spanwise thickness distribution of the structure. The effect of spars and propulsion system positioning on the available storage space, maximum stress and displacement is discussed, with the aft spar having the greatest impact. Finally, the structural model is optimized to minimize the mass, resulting in a 29% weight reduction, compared to the initial design.
{"title":"Structural optimization of the wing box for a hybrid-electric commuter aircraft","authors":"C. Nasoulis, P. Tsirikoglou, A. Kalfas","doi":"10.33737/jgpps/151116","DOIUrl":"https://doi.org/10.33737/jgpps/151116","url":null,"abstract":"Hybrid-electric commuter aircraft segment is playing a significant role in the electrification of air transportation. Towards the achievement of efficient and robust transportation, design and optimization processes are necessary to evaluate the different aircraft components. Within this context, the current work investigates the impact of the positioning of the propulsion system and spars on the structural integrity of a hybrid-electric commuter aircraft. The proposed approach is based on an in-house aircraft sizing tool, along with geometry generation and high-fidelity structural evaluation models. These tools are tailored in an automated computational pipeline, that includes pre-processing, model evaluation and post-processing tasks, able to perform design space exploration and optimization over different loading conditions of a selected mission envelope. This work focuses on the assessment of the impact of the additional non-structural weight e.g., batteries, fuel, and propulsion components, inside the wing box, on the stress, deformation and spanwise thickness distribution of the structure. The effect of spars and propulsion system positioning on the available storage space, maximum stress and displacement is discussed, with the aft spar having the greatest impact. Finally, the structural model is optimized to minimize the mass, resulting in a 29% weight reduction, compared to the initial design.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47899666","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}
A coupled time and passage spectral method has been proposed very recently for tracking blade wakes penetrating the immediate downstream blade row and reaching far downstream blade rows. To achieve an efficient numerical analysis, the number of time and space modes to be retained has to be limited, as the computational cost of such an analysis is at least proportional to the number of modes. In this study, time and space modes related to downstream propagation of blade wakes reaching beyond their immediate downstream blade row are ranked according to their amplitudes of flow quantities through a time domain harmonic balance analysis using a domain consisting of multiple blade passages for the third row to capture the wakes of the first row of a two-stage fan. Modes with significant amplitudes are identified and they are really sparse. This sparsity of significant modes provides the premise for an efficient analysis using the coupled time and passage spectral method. A guideline for a priori selection of time and space modes has been developed by analyzing the frequencies and nodal diameters of those significant modes. The guideline is subsequently verified through four different coupled time and passage spectral analyses with different levels of accuracy by including different time and space modes.
{"title":"Efficient analysis of unsteady flows within multi-stage turbomachines using the coupled time and passage spectral method","authors":"Dingxi Wang, Sen Zhang, Xiuquan Huang","doi":"10.33737/jgpps/151117","DOIUrl":"https://doi.org/10.33737/jgpps/151117","url":null,"abstract":"A coupled time and passage spectral method has been proposed very recently for tracking blade wakes penetrating the immediate downstream blade row and reaching far downstream blade rows. To achieve an efficient numerical analysis, the number of time and space modes to be retained has to be limited, as the computational cost of such an analysis is at least proportional to the number of modes. In this study, time and space modes related to downstream propagation of blade wakes reaching beyond their immediate downstream blade row are ranked according to their amplitudes of flow quantities through a time domain harmonic balance analysis using a domain consisting of multiple blade passages for the third row to capture the wakes of the first row of a two-stage fan. Modes with significant amplitudes are identified and they are really sparse. This sparsity of significant modes provides the premise for an efficient analysis using the coupled time and passage spectral method. A guideline for a priori selection of time and space modes has been developed by analyzing the frequencies and nodal diameters of those significant modes. The guideline is subsequently verified through four different coupled time and passage spectral analyses with different levels of accuracy by including different time and space modes.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45656014","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}
The impulse response method is widely used for heat transfer analysis in turbomachinery applications. Traditionally, the 1D method assumes a linear time invariant, isotropic, semi-infinite block and does not accurately model the behaviour of laminated materials. This paper evaluates the error introduced by the single layer assumption and outlines the required modifications for multilayer analysis. The analytic solution for an N layer, semi-infinite laminate is presented. Adapted multilayer basis functions are derived for the impulse response method and used to evaluate the impact of uniform, isotropic assumptions. A numerical solution to the laminate problem is also presented. A penta-diagonal inversion algorithm, for a modified Crank-Nicolson scheme, is evaluated for fast stable implementation of multilayer simulation. The scheme shows comparable performance to the impulse response, whilst removing the requirement for linear time invariance. The methods are demonstrated in the case of analysing a thin film gauge, used in laboratory analysis of heat transfer in a turbine nozzle guide vane. Thin film gauge manufacturing techniques have advanced significantly in recent years. Advanced multilayer constructions are now used however, post-processing commonly relies on outdated single layer methods. This paper provides a universal methodology, required to analyse modern-day multilayer heat transfer measurements.
{"title":"1D analytic and numerical analysis of multilayer laminates and thin film heat transfer gauges","authors":"M. Baker, B. Rosic","doi":"10.33737/jgpps/151660","DOIUrl":"https://doi.org/10.33737/jgpps/151660","url":null,"abstract":"The impulse response method is widely used for heat transfer analysis in turbomachinery applications. Traditionally, the 1D method assumes a linear time invariant, isotropic, semi-infinite block and does not accurately model the behaviour of laminated materials. This paper evaluates the error introduced by the single layer assumption and outlines the required modifications for multilayer analysis.\u0000\u0000The analytic solution for an N layer, semi-infinite laminate is presented. Adapted multilayer basis functions are derived for the impulse response method and used to evaluate the impact of uniform, isotropic assumptions. A numerical solution to the laminate problem is also presented. A penta-diagonal inversion algorithm, for a modified Crank-Nicolson scheme, is evaluated for fast stable implementation of multilayer simulation. The scheme shows comparable performance to the impulse response, whilst removing the requirement for linear time invariance.\u0000\u0000The methods are demonstrated in the case of analysing a thin film gauge, used in laboratory analysis of heat transfer in a turbine nozzle guide vane. Thin film gauge manufacturing techniques have advanced significantly in recent years. Advanced multilayer constructions are now used however, post-processing commonly relies on outdated single layer methods. This paper provides a universal methodology, required to analyse modern-day multilayer heat transfer measurements.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48623700","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}
Ina Ekeberg, Pierre-Jean Bibet, H. Knudsen, Øyvind Reimers, E. Torbergsen
Over the past ten years, subsea multiphase pumping has accomplished extraordinary technology breakthroughs. The drivers are the oil and gas companies’ requirements for deeper and more remote subsea production satellites along with producing more challenging fluids. The multiphase pump (MPP) technology has kept evolving, breaking records in terms of shaft power, design pressure, differential pressure, and high viscosity capabilities. In addition, the current reliability data shows 86.5% probability of 5 years failure-free operation. Today, a main challenge is the ability to withstand sand erosion. A subsea MPP is placed on the seafloor to increase the production from subsea oil and gas wells, normally without any upstream separator or sand control system. The inevitable sand production is directed through the pump and transported further to the topside arrival separator. The MPP considered in this paper is a dynamic helico-axial pump with rotational speeds typically ranging up to 4,600 rpm and 3.5 MW. Obviously, both pump vendor and operator have made significant efforts to make the MPP as robust as possible. The first part of this paper describes how sand production is mitigated and controlled in a subsea oil and gas production system, but also how an accidental sand event can nevertheless happen. In the second part, the various wear mechanisms of MPP components are explained based on operational experience and wear tests. Finally, it presents the comparison of the wear observed on the Moho pump retrieved from the field with the wear rate and pattern predicted by the in-house MPP wear prediction model.
{"title":"Sand management and erosion prediction in subsea multiphase pumps","authors":"Ina Ekeberg, Pierre-Jean Bibet, H. Knudsen, Øyvind Reimers, E. Torbergsen","doi":"10.33737/jgpps/145322","DOIUrl":"https://doi.org/10.33737/jgpps/145322","url":null,"abstract":"Over the past ten years, subsea multiphase pumping has accomplished extraordinary technology breakthroughs. The drivers are the oil and gas companies’ requirements for deeper and more remote subsea production satellites along with producing more challenging fluids. The multiphase pump (MPP) technology has kept evolving, breaking records in terms of shaft power, design pressure, differential pressure, and high viscosity capabilities. In addition, the current reliability data shows 86.5% probability of 5 years failure-free operation. Today, a main challenge is the ability to withstand sand erosion.\u0000\u0000A subsea MPP is placed on the seafloor to increase the production from subsea oil and gas wells, normally without any upstream separator or sand control system. The inevitable sand production is directed through the pump and transported further to the topside arrival separator. The MPP considered in this paper is a dynamic helico-axial pump with rotational speeds typically ranging up to 4,600 rpm and 3.5 MW. Obviously, both pump vendor and operator have made significant efforts to make the MPP as robust as possible.\u0000\u0000The first part of this paper describes how sand production is mitigated and controlled in a subsea oil and gas production system, but also how an accidental sand event can nevertheless happen. In the second part, the various wear mechanisms of MPP components are explained based on operational experience and wear tests. Finally, it presents the comparison of the wear observed on the Moho pump retrieved from the field with the wear rate and pattern predicted by the in-house MPP wear prediction model.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48010655","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. Pohl, J. Köhler, H. Kellermann, Michael Lüdemann, Daniel Weintraub, P. Jeschke, M. Hornung
This paper presents a novel tool for the modeling of partial turboelectric propulsion systems together with a corresponding case study for a commercial single-aisle aircraft. In order to reduce the environmental impact of air traffic, radically new aircraft and propulsion concepts with a high market penetration are needed. Partial turboelectric propulsion systems seem to offer a promising option to achieve this. For the development of these propulsion systems, a preliminary design tool with a homogeneous and sufficiently high fidelity, both for turbomachinery and electric components, is needed. To address this, the authors of this publication have developed a tool based on the GasTurb software. The models developed, in particular for the electric components which together form the electric powertrain, are described here. In the case study, which demonstrates the coupling of the developed tool with an aircraft design environment, a conventional turboprop baseline aircraft is compared to a derived aircraft which features a partial turboelectric propulsion system with wingtip propellers. The latter are intended to reduce the induced drag, enabling a reduction of the aircraft's total shaft power demand compared to the conventional baseline aircraft. The comparison between the partial turboelectric aircraft and the baseline aircraft indicates that fuel reduction increases with power split. However, primarily increasing electric powertrain masses and a stagnating drag reduction result in lower additional fuel reductions for higher power splits. Despite these conclusions, the predicted induced drag reductions need further refinement as they were found to be optimistic. In summary, this publication presents a methodology and a set of physics-based component models for the preliminary design of partial turboelectric propulsion systems, so that the electric components can be investigated and optimized at the same high level of detail as the gas turbine.
{"title":"Preliminary Design of Integrated Partial Turboelectric Aircraft Propulsion Systems","authors":"M. Pohl, J. Köhler, H. Kellermann, Michael Lüdemann, Daniel Weintraub, P. Jeschke, M. Hornung","doi":"10.33737/jgpps/145907","DOIUrl":"https://doi.org/10.33737/jgpps/145907","url":null,"abstract":"This paper presents a novel tool for the modeling of partial turboelectric propulsion systems together with a corresponding case study for a commercial single-aisle aircraft. In order to reduce the environmental impact of air traffic, radically new aircraft and propulsion concepts with a high market penetration are needed. Partial turboelectric propulsion systems seem to offer a promising option to achieve this. For the development of these propulsion systems, a preliminary design tool with a homogeneous and sufficiently high fidelity, both for turbomachinery and electric components, is needed. To address this, the authors of this publication have developed a tool based on the GasTurb software. The models developed, in particular for the electric components which together form the electric powertrain, are described here. In the case study, which demonstrates the coupling of the developed tool with an aircraft design environment, a conventional turboprop baseline aircraft is compared to a derived aircraft which features a partial turboelectric propulsion system with wingtip propellers. The latter are intended to reduce the induced drag, enabling a reduction of the aircraft's total shaft power demand compared to the conventional baseline aircraft. The comparison between the partial turboelectric aircraft and the baseline aircraft indicates that fuel reduction increases with power split. However, primarily increasing electric powertrain masses and a stagnating drag reduction result in lower additional fuel reductions for higher power splits. Despite these conclusions, the predicted induced drag reductions need further refinement as they were found to be optimistic. In summary, this publication presents a methodology and a set of physics-based component models for the preliminary design of partial turboelectric propulsion systems, so that the electric components can be investigated and optimized at the same high level of detail as the gas turbine.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45349439","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}
Methodologies to quantify the impact of manufacturing uncertainties in 3D CFD based design strategies have become increasingly available over the past years as well as optimization under uncertainties, aiming at reducing the systems sensitivity to manufacturing uncertainties. This type of non-deterministic simulation depends however strongly on a correct characterization of the manufacturing variability. Experimental data to characterize this variability is not always available or in many cases cannot be sampled in sufficiently high numbers. Principal Component Analysis (PCA) is applied to the sampled geometries and the influence of tolerances classes, sample size and number of retained deformation modes are discussed. It is shown that the geometrical reconstruction accuracy of the deformation modes and reconstruction accuracy of the CFD predictions are not linearly related, which has important implications on the total geometrical variance that needs to be retained. In a second application the characterization of manufacturing uncertainties to a marine propeller is discussed. It is shown that uncertainty quantification and robust design optimization of the marine propeller can successfully be performed on the basis of the derived uncertainties. This leads to a propeller shape that is less sensitive to the manufacturing variability and therefore to a more robust design.
{"title":"Characterization of manufacturing uncertainties with applications to uncertainty quantification and robust design optimization","authors":"D. Wunsch, C. Hirsch","doi":"10.33737/JGPPS/138902","DOIUrl":"https://doi.org/10.33737/JGPPS/138902","url":null,"abstract":"Methodologies to quantify the impact of manufacturing uncertainties in 3D CFD based design strategies have\u0000become increasingly available over the past years as well as optimization under uncertainties, aiming at reducing the\u0000systems sensitivity to manufacturing uncertainties. This type of non-deterministic simulation depends however\u0000strongly on a correct characterization of the manufacturing variability. Experimental data to characterize this\u0000variability is not always available or in many cases cannot be sampled in sufficiently high numbers. Principal\u0000Component Analysis (PCA) is applied to the sampled geometries and the influence of tolerances classes, sample size\u0000and number of retained deformation modes are discussed. It is shown that the geometrical reconstruction accuracy of\u0000the deformation modes and reconstruction accuracy of the CFD predictions are not linearly related, which has\u0000important implications on the total geometrical variance that needs to be retained. In a second application the\u0000characterization of manufacturing uncertainties to a marine propeller is discussed. It is shown that uncertainty\u0000quantification and robust design optimization of the marine propeller can successfully be performed on the basis of\u0000the derived uncertainties. This leads to a propeller shape that is less sensitive to the manufacturing variability and\u0000therefore to a more robust design.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46726305","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, Lars Wein, Dajan Mimic, Philipp Gilge, Ulrich Hartmann, J. Seume
Defects in the hot-gas path of aero engines have been shown to leave typical signatures in the density distribution of the exhaust jet. These signatures are superposed when several defects are present. For improved maintenance and monitoring applications, it is important to not only detect that there are defects present but to also identify the individual classes of defects. This diagnostic approach benefits both, the analysis of prototype or acceptance test and the preparation of Maintenance, Repair, and Overhaul. Recent advances in the analysis of tomographic Background-Oriented Schlieren (BOS) data have enabled the technique to be automated such that typical defects in the hot-gas path of gas turbines can be detected and distinguished automatically. This automation is achieved by using Support Vector Machine (SVM) algorithms. Choosing suitable identification parameters is critical and can enable SVM algorithms to distinguish between different defect types. The results show that the SVM can be trained such that almost no defects are missed and that false attributions of defect classes can be minimized.
{"title":"Automated detection of hot-gas path defects by Support Vector Machine based analysis of exhaust density fields","authors":"M. Oettinger, Lars Wein, Dajan Mimic, Philipp Gilge, Ulrich Hartmann, J. Seume","doi":"10.33737/JGPPS/137952","DOIUrl":"https://doi.org/10.33737/JGPPS/137952","url":null,"abstract":"Defects in the hot-gas path of aero engines have been shown to leave typical signatures in the density distribution of the exhaust jet. These signatures are superposed when several defects are present. For improved maintenance and monitoring applications, it is important to not only detect that there are defects present but to also identify the individual classes of defects. This diagnostic approach benefits both, the analysis of prototype or acceptance test and the preparation of Maintenance, Repair, and Overhaul.\u0000Recent advances in the analysis of tomographic Background-Oriented Schlieren (BOS) data have enabled the technique to be automated such that typical defects in the hot-gas path of gas turbines can be detected and distinguished automatically. This automation is achieved by using Support Vector Machine (SVM) algorithms. Choosing suitable identification parameters is critical and can enable SVM algorithms to distinguish between different defect types. The results show that the SVM can be trained such that almost no defects are missed and that false attributions of defect classes can be minimized.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48404733","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 : 2021-01-08DOI: 10.32743/2658-4077.2021.1.21.417
A. Koptelov
{"title":"THE ENGLISH-LANGUAGE HISTORIOGRAPHY OF THE XXI CENTURE OF THE POLITICAL POLICE OF THE RUSSIAN EMPIRE XIX-EARLY XX CENTURE","authors":"A. Koptelov","doi":"10.32743/2658-4077.2021.1.21.417","DOIUrl":"https://doi.org/10.32743/2658-4077.2021.1.21.417","url":null,"abstract":"","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":"129 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76153957","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}
The development of efficient low emission combustion systems requires methods for an accurate and reliable prediction of combustion processes. Computational Fluid Dynamics (CFD) in combination with combustion modelling is an important tool to achieve this goal. For an accurate computation adequate boundary conditions are crucial. Especially data for the temperature distribution on the walls of the combustion chamber are usually not available. The present work focuses on numerical simulations of a high momentum jet flame in a single nozzle FLOX® type model combustion chamber at elevated pressure. Alongside the balance equations for the fluid the energy equation for the solid combustor walls is solved. To assess the accuracy of this approach, the temperature distribution on the inner combustion chamber wall resulting from this Conjugate Heat Transfer (CHT) simulation is compared to measured wall temperatures. The simulation results within the combustion chamber are compared to detailed experimental data. This includes a comparison of the flow velocities, temperatures as well as species concentrations. To further assess the benefit of including the solid domain in a CFD simulation the results of the CHT simulation are compared to results of a CFD computation where constant temperatures are assumed for all walls of the combustion chamber.
{"title":"Numerical Investigation of a High Momentum Jet Flame at Elevated Pressure: A Quantitative Validation with Detailed Experimental Data","authors":"Michael Pries, A. Fiolitakis, P. Gerlinger","doi":"10.33737/jgpps/130031","DOIUrl":"https://doi.org/10.33737/jgpps/130031","url":null,"abstract":"The development of efficient low emission combustion systems requires methods for an accurate and reliable prediction of combustion processes. Computational Fluid Dynamics (CFD) in combination with combustion modelling is an important tool to achieve this goal. For an accurate computation adequate boundary conditions are crucial. Especially data for the temperature distribution on the walls of the combustion chamber are usually not available. \u0000The present work focuses on numerical simulations of a high momentum jet flame in a single nozzle FLOX® type model combustion chamber at elevated pressure. Alongside the balance equations for the fluid the energy equation for the solid combustor walls is solved. To assess the accuracy of this approach, the temperature distribution on the inner combustion chamber wall resulting from this Conjugate Heat Transfer (CHT) simulation is compared to measured wall temperatures. The simulation results within the combustion chamber are compared to detailed experimental data. This includes a comparison of the flow velocities, temperatures as well as species concentrations. To further assess the benefit of including the solid domain in a CFD simulation the results of the CHT simulation are compared to results of a CFD computation where constant temperatures are assumed for all walls of the combustion chamber.","PeriodicalId":53002,"journal":{"name":"Journal of the Global Power and Propulsion Society","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49580060","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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