Pub Date : 2001-09-01DOI: 10.1017/S0001924000018029
G. Mengall
A new methodology is described to identify aircraft dynamics and extract the corresponding aerodynamic coefficients. The proposed approach makes use of fuzzy modelling for the identification process where input/output data are first classified by means of the concept of fuzzy clustering and then the linguistic rules are extracted from the fuzzy clusters. The fuzzy rule-based models are in the form of affine Takagi-Sugeno models, that are able to approximate a large class of nonlinear systems. A comparative study is performed with existing techniques based on the employment of neural networks, showing interesting advantages of the proposed methodology both for the physical insight of the identified model and the simplicity to obtain accurate results with fewer parameters to be properly tuned.
{"title":"Fuzzy modelling for aircraft dynamics identification","authors":"G. Mengall","doi":"10.1017/S0001924000018029","DOIUrl":"https://doi.org/10.1017/S0001924000018029","url":null,"abstract":"A new methodology is described to identify aircraft dynamics and extract the corresponding aerodynamic coefficients. The proposed approach makes use of fuzzy modelling for the identification process where input/output data are first classified by means of the concept of fuzzy clustering and then the linguistic rules are extracted from the fuzzy clusters. The fuzzy rule-based models are in the form of affine Takagi-Sugeno models, that are able to approximate a large class of nonlinear systems. A comparative study is performed with existing techniques based on the employment of neural networks, showing interesting advantages of the proposed methodology both for the physical insight of the identified model and the simplicity to obtain accurate results with fewer parameters to be properly tuned.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2001-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000018029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57253048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-08-01DOI: 10.1017/S0001924000012458
A. Bhaskar
{"title":"Principles of Optimal Design: Modeling and Computation P. Y. Papalambros and D. J. Wilde Second edition. Cambridge University Press, The Edinburgh Building, Cambridge CB2 2RU, UK. 2000. 390pp. Illustrated. £27.95. ISBN 0-521-62727-3.","authors":"A. Bhaskar","doi":"10.1017/S0001924000012458","DOIUrl":"https://doi.org/10.1017/S0001924000012458","url":null,"abstract":"","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2001-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79444084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-12-01DOI: 10.1017/S0001924000096901
D. Allerton
This paper outlines the development of flight simulators used in civil training, military training and in engineering simulation. It describes the evolution of flight simulators and the typical architecture of a modern flight simulator. The technical innovations, which have occurred in modelling, motion systems and visual systems are reviewed. The paper also reviews the transfer of training in flight simulation, the application of simulation to engineering design and outlines problems which are encountered in flight simulation. The paper concludes by reviewing the current trends in flight simulation.
{"title":"Flight simulation : past, present and future","authors":"D. Allerton","doi":"10.1017/S0001924000096901","DOIUrl":"https://doi.org/10.1017/S0001924000096901","url":null,"abstract":"This paper outlines the development of flight simulators used in civil training, military training and in engineering simulation. It describes the evolution of flight simulators and the typical architecture of a modern flight simulator. The technical innovations, which have occurred in modelling, motion systems and visual systems are reviewed. The paper also reviews the transfer of training in flight simulation, the application of simulation to engineering design and outlines problems which are encountered in flight simulation. The paper concludes by reviewing the current trends in flight simulation.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57256046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-08-01DOI: 10.1017/S0001924000064009
Ajay Mahaputra Kumar, Jerry, N.
Abstract Investments in aeronautics research and technology have declined substantially over the last decade, in part due to the perception that technologies required in aircraft design are fairly mature and readily available. This perception is being driven by the fact that aircraft configurations, particularly the transport aircraft, have evolved only incrementally over the last several decades. If, however, one considers that the growth in air travel is expected to triple in the next 20 years, it becomes quickly obvious that the evolutionary development of technologies is not going to meet the increased demands for safety, environmental compatibility, capacity, and economic viability. Instead, breakthrough technologies will be required both in traditional disciplines of aerodynamics, propulsion, structures, materials, controls and avionics as well as in the multidisciplinary integration of these technologies into the design of future aerospace vehicles concepts. The paper discusses challenges and opportunities in the field of aerodynamics over the next decade. Future technology advancements in aerodynamics will hinge on our ability to understand, model and control complex, three-dimensional, unsteady viscous flow across the speed range. This understanding is critical for developing innovative flow and noise control technologies and advanced design tools that will revolutionise future aerospace vehicle systems and concepts. Specifically, the paper focuses on advanced vehicle concepts, flow and noise control technologies, and advanced design and analysis tools.
{"title":"Future challenges and opportunities in aerodynamics","authors":"Ajay Mahaputra Kumar, Jerry, N.","doi":"10.1017/S0001924000064009","DOIUrl":"https://doi.org/10.1017/S0001924000064009","url":null,"abstract":"Abstract Investments in aeronautics research and technology have declined substantially over the last decade, in part due to the perception that technologies required in aircraft design are fairly mature and readily available. This perception is being driven by the fact that aircraft configurations, particularly the transport aircraft, have evolved only incrementally over the last several decades. If, however, one considers that the growth in air travel is expected to triple in the next 20 years, it becomes quickly obvious that the evolutionary development of technologies is not going to meet the increased demands for safety, environmental compatibility, capacity, and economic viability. Instead, breakthrough technologies will be required both in traditional disciplines of aerodynamics, propulsion, structures, materials, controls and avionics as well as in the multidisciplinary integration of these technologies into the design of future aerospace vehicles concepts. The paper discusses challenges and opportunities in the field of aerodynamics over the next decade. Future technology advancements in aerodynamics will hinge on our ability to understand, model and control complex, three-dimensional, unsteady viscous flow across the speed range. This understanding is critical for developing innovative flow and noise control technologies and advanced design tools that will revolutionise future aerospace vehicle systems and concepts. Specifically, the paper focuses on advanced vehicle concepts, flow and noise control technologies, and advanced design and analysis tools.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000064009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57254927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-11-01DOI: 10.1017/S0001924000064253
B. V. van Oudheusden
Abstract An experimental investigation was carried out of the incompressible boundary layer flow along a flat plate, in the presence of an adverse pressure gradient that corresponds to a linear retardation of the free stream velocity. The turbulence level in the free-stream was 0·12% and transition occurred with the laminar boundary layer being close to separation. For three values of the Reynolds number (2·56, 3·11 and 4·09 million based on the reference length that is defined as the reciprocal of the nondimensional-velocity gradient) the laminar, transitional and turbulent regions were studied by single (normal) hot-wire surveys at several streamwise positions. This allows the fluctuations of the streamwise velocity component to be followed from the amplification of laminar instability waves, through breakdown in the intermittency region, and the subsequent development towards a more or less developed turbulence structure. The study reveals that within the transition region fluctuation levels are reached throughout a large part of the boundary layer that are significantly higher than those in fully developed turbulent flow, which is partly a direct consequence of the intermittent character of the flow. For the highest Reynolds number additional cross-wire surveys were carried out in the turbulent region to observe the development of the turbulent stresses following transition. The data are interpreted in terms of structural coefficients, eddy viscosity and mixing length. Also, these results indicate that the transition process can be associated with turbulence levels well in excess of those occurring in fully developed turbulence, and reveal the relaxation of the outer region turbulence structure.
{"title":"An experimental study of transition and the development of turbulence in a linearly retarded boundary-layer flow","authors":"B. V. van Oudheusden","doi":"10.1017/S0001924000064253","DOIUrl":"https://doi.org/10.1017/S0001924000064253","url":null,"abstract":"Abstract An experimental investigation was carried out of the incompressible boundary layer flow along a flat plate, in the presence of an adverse pressure gradient that corresponds to a linear retardation of the free stream velocity. The turbulence level in the free-stream was 0·12% and transition occurred with the laminar boundary layer being close to separation. For three values of the Reynolds number (2·56, 3·11 and 4·09 million based on the reference length that is defined as the reciprocal of the nondimensional-velocity gradient) the laminar, transitional and turbulent regions were studied by single (normal) hot-wire surveys at several streamwise positions. This allows the fluctuations of the streamwise velocity component to be followed from the amplification of laminar instability waves, through breakdown in the intermittency region, and the subsequent development towards a more or less developed turbulence structure. The study reveals that within the transition region fluctuation levels are reached throughout a large part of the boundary layer that are significantly higher than those in fully developed turbulent flow, which is partly a direct consequence of the intermittent character of the flow. For the highest Reynolds number additional cross-wire surveys were carried out in the turbulent region to observe the development of the turbulent stresses following transition. The data are interpreted in terms of structural coefficients, eddy viscosity and mixing length. Also, these results indicate that the transition process can be associated with turbulence levels well in excess of those occurring in fully developed turbulence, and reveal the relaxation of the outer region turbulence structure.","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"1999-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S0001924000064253","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57255117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-10-01DOI: 10.1017/S0001924000064447
C. Beards
{"title":"Introduction to Finite Element Vibration Analysis. M. Petyt. Cambridge University Press, The Edinburgh Building, Cambridge CB2 2RU, UK. 1998. 558pp. Illustrated. £35.","authors":"C. Beards","doi":"10.1017/S0001924000064447","DOIUrl":"https://doi.org/10.1017/S0001924000064447","url":null,"abstract":"","PeriodicalId":50846,"journal":{"name":"Aeronautical Journal","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79643978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：