The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Alain Vautrin - One of the best experts on this subject based on the ideXlab platform.
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Accelerated hygrothermal cyclical tests for carbon/epoxy laminates
2020Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper is related to a Supersonic transportation application where polymer matrix composites utilized in primary structures are subjected to particular hygrothermal Flight-cycles. In fact, the particular point in this study is the drying effect of Supersonic Flight at high temperature, around 130°C, on the durability of the material. This phenomenon constitutes an entirely new situation for these materials in contrast with a classical subsonic Flight at low temperature. The Supersonic aircraft is supposed to be subjected to a succession of Supersonic Flight-cycles followed by a periodic maintenance operation. The objective of the study is first to characterize the in-service material state during the Supersonic Flight cycles and after the maintenance operations. Then, the challenge is to define the material geometry and environmental conditions to meet the in-service material state in short time. Thus, different accelerated cycles adapted to the new situation of Supersonic Flights, i.e. focusing on the cyclical drying of the material, are proposed.
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Accelerated hygrothermal cyclical tests for carbon/epoxy laminates
Composites Part A-applied Science and Manufacturing, 2006Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper deals with the design of reasonable accelerated test conditions to assess polymer matrix composite durability when it is subjected to Supersonic Flight-cycles. The study is closely linked to novel application of carbon fibre polymer matrix composites in Supersonic aircraft primary structures, leading to substantial weight saving and stiffness improvement. A Supersonic Flight can result in surface temperatures close to 130 °C, inducing severe thermal gradients and drying which are quite new for this type of materials, now used in primary structures of subsonic jets operating at low subsonic Flight-temperatures. Therefore, the particular effect of the drying on the long-term behaviour of composites should be investigated. Numerical simulations based on Fick's law confirm that the Supersonic Flight-cycles induce a material drying on the long-term and a significant moisture uptake occurs during the aircraft maintenance periods. Then, particular accelerated cycles are proposed to approach the effect of the drying and moisture uptake during service life. First experiments showed that the long-term hygrothermal fatigue can induce significant changes in the material properties and a drop in the glass transition temperature of about 20 °C.
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design of accelerated hygrothermal cycles on polymer matrix composites in the case of a Supersonic aircraft
Composite Structures, 2005Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper is related to a Supersonic transportation application where polymer matrix composites utilized in primary structures are subjected to particular hygrothermal Flight-cycles. In fact, the particular point in this study is the drying effect of Supersonic Flight at high temperature, around 130 °C, on the durability of the material. This phenomenon constitutes an entirely new situation for these materials in contrast with a classical subsonic Flight at low temperature. The Supersonic aircraft is supposed to be subjected to a succession of Supersonic Flight-cycles followed by a periodic maintenance operation. The objective of the study is first to characterize the in-service material state during the Supersonic Flight cycles and after the maintenance operations. Then, the challenge is to define the material geometry and environmental conditions to meet the in-service material state in short time. Thus, different accelerated cycles adapted to the new situation of Supersonic Flights, i.e. focusing on the cyclical drying of the material, are proposed.
Ronald Beard - One of the best experts on this subject based on the ideXlab platform.
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NASA EDGE: Low-Boom Flight Demonstration Promo
2020Co-Authors: Ronald BeardAbstract:The great aviation transformation begins now as NASA moves ahead with the development of an X-Plane designed to demonstrate low-boom technology and promote regulatory change for commercial Supersonic Flight.
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NASA EDGE: The Future Of Commercial Supersonic Travel
2020Co-Authors: Ronald BeardAbstract:NASA Langley Research Center’s Peter Coen (Commercial Supersonic Technology Program Manager) and David Richwine (Quiet Supersonic Technology Project Manager) explain how advances in design could help reduce the impact of sonic booms and promote Supersonic Flight over land.
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NASA EDGE: Low-Boom Flight Demonstration
2020Co-Authors: Ronald BeardAbstract:NASA EDGE is joined in studio by David Richwine, Deputy Project Manager for Technology for the Low-Boom Flight Demonstration to discuss NASA's current effort to develop ground breaking aircraft design and promote regulatory change for commercial Supersonic Flight over land.
Jihed Jedidi - One of the best experts on this subject based on the ideXlab platform.
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Accelerated hygrothermal cyclical tests for carbon/epoxy laminates
2020Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper is related to a Supersonic transportation application where polymer matrix composites utilized in primary structures are subjected to particular hygrothermal Flight-cycles. In fact, the particular point in this study is the drying effect of Supersonic Flight at high temperature, around 130°C, on the durability of the material. This phenomenon constitutes an entirely new situation for these materials in contrast with a classical subsonic Flight at low temperature. The Supersonic aircraft is supposed to be subjected to a succession of Supersonic Flight-cycles followed by a periodic maintenance operation. The objective of the study is first to characterize the in-service material state during the Supersonic Flight cycles and after the maintenance operations. Then, the challenge is to define the material geometry and environmental conditions to meet the in-service material state in short time. Thus, different accelerated cycles adapted to the new situation of Supersonic Flights, i.e. focusing on the cyclical drying of the material, are proposed.
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Accelerated hygrothermal cyclical tests for carbon/epoxy laminates
Composites Part A-applied Science and Manufacturing, 2006Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper deals with the design of reasonable accelerated test conditions to assess polymer matrix composite durability when it is subjected to Supersonic Flight-cycles. The study is closely linked to novel application of carbon fibre polymer matrix composites in Supersonic aircraft primary structures, leading to substantial weight saving and stiffness improvement. A Supersonic Flight can result in surface temperatures close to 130 °C, inducing severe thermal gradients and drying which are quite new for this type of materials, now used in primary structures of subsonic jets operating at low subsonic Flight-temperatures. Therefore, the particular effect of the drying on the long-term behaviour of composites should be investigated. Numerical simulations based on Fick's law confirm that the Supersonic Flight-cycles induce a material drying on the long-term and a significant moisture uptake occurs during the aircraft maintenance periods. Then, particular accelerated cycles are proposed to approach the effect of the drying and moisture uptake during service life. First experiments showed that the long-term hygrothermal fatigue can induce significant changes in the material properties and a drop in the glass transition temperature of about 20 °C.
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design of accelerated hygrothermal cycles on polymer matrix composites in the case of a Supersonic aircraft
Composite Structures, 2005Co-Authors: Jihed Jedidi, Frederic Jacquemin, Alain VautrinAbstract:The paper is related to a Supersonic transportation application where polymer matrix composites utilized in primary structures are subjected to particular hygrothermal Flight-cycles. In fact, the particular point in this study is the drying effect of Supersonic Flight at high temperature, around 130 °C, on the durability of the material. This phenomenon constitutes an entirely new situation for these materials in contrast with a classical subsonic Flight at low temperature. The Supersonic aircraft is supposed to be subjected to a succession of Supersonic Flight-cycles followed by a periodic maintenance operation. The objective of the study is first to characterize the in-service material state during the Supersonic Flight cycles and after the maintenance operations. Then, the challenge is to define the material geometry and environmental conditions to meet the in-service material state in short time. Thus, different accelerated cycles adapted to the new situation of Supersonic Flights, i.e. focusing on the cyclical drying of the material, are proposed.
Kazuhiro Nakahashi - One of the best experts on this subject based on the ideXlab platform.
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Toward silent Supersonic transport—A fundamental study of Supersonic biplane
Journal of the Acoustical Society of America, 2006Co-Authors: Kazuhiro Kusunose, Daigo Maruyama, Kisa Matsushima, Kazuhiro Nakahashi, Hiroshi Yamashita, Masahito Yonezawa, Shigeru ObayashiAbstract:In this research, aerodynamic design of biplane airfoils in Supersonic Flight is discussed based on computational fluid dynamics (CFD). In Supersonic Flight, airfoils generate strong sonic booms and wave drags accompanied by shock waves. New airfoil geometries which significantly reduce shock waves using a biplane concept will be proposed. The background of this concept originates from Busemann biplane and Licher type biplane concepts. In order to focus on the shock‐wave characteristics around biplane configuration, inviscid flow (Euler) analyses are performed (which are particularly suitable for wave drag analyses). For the evaluation of the reduction level of shock waves, the wave drag coefficient is used. The design Mach number is 1.7. The aerodynamic design is conducted using an iterative inverse design method that is newly implemented. A biplane configuration with a desired performance has been obtained. Having total maximum thickness ratio of 0.10, it has the lift‐to‐wave‐drag ratio of 21.7 at a des...
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aerodynamic design of biplane airfoils for low wave drag Supersonic Flight
24th AIAA Applied Aerodynamics Conference, 2006Co-Authors: Daigo Maruyama, Kisa Matsushima, Kazuhiro Kusunose, Kazuhiro NakahashiAbstract:In this paper, aerodynamic design of biplane airfoils in Supersonic Flight is discussed based on Computational Fluid Dynamics (CFD). In Supersonic Flight, airfoils generate strong sonic booms and wave drags accompanied by shock waves. We propose a significant reduction of them, especially wave drags using a biplane-airfoil concept. The background of this concept is originated from Busemann biplane and Licher type biplane concepts. In order to focus on the shock wave characteristics around biplane configuration, inviscid flow (Euler) analyses are performed (which is particularly suitable for wave drag analyses). Design Mach number is 1.7. The aerodynamic design is conducted using an iterative inverse design method that is newly implemented. A biplane configuration having a desired performance has been obtained. Having 0.102 of total maximum thickness ratio (t/c), it has the lift to wave drag ratio (L/D) of 21.7 at a desired lift condition for Supersonic Flight, lift coefficient (Cl)=0.115. At the range of lift coefficient more than 0.144 this designed biplane has lower wave drag than that of a (zero-thickness) single flat plate airfoil.
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aerodynamic analyses of airfoil configurations of biplane type Supersonic transport
Transactions of the Japan Society of Mechanical Engineers. B, 2006Co-Authors: Daigo Maruyama, Kisa Matsushima, Kazuhiro NakahashiAbstract:In Supersonic Flight, airplanes cause strong sonic booms and wave drags accompanied by shock waves. It is necessary that airplanes have low noises and high efficiencies to realize next generation Supersonic transports. It has high possibility that these two objectives can be achieved using a concept of Busemann Biplane. Motivated by the concept, aerodynamic design of biplane configuration in Supersonic Flight is discussed based on Computational Fluid Dynamics (CFD). In order to focus on the shock wave characteristics around a biplane configuration, inviscid flow (Euler) analyses are performed, which is particularly suitable for wave drag analyses. The purpose of this paper is to examine characteristics of Busemann Biplane and to demonstrate new biplane configurations which have better aerodynamic performance based on Busemann Biplane. The aerodynamic design is performed using an iterative inverse design method that has been recently implemented. This is the method that geometries are detemined by given target pressure distributions. We expect that the inverse design method may prove to be a highly appropriate tool in finding a biplane configuration to achieve minimum wave drag under a given lift condition. By the use of the inverse design method an improved airfoil shape for the biplane has been obtained
Jeff Hecht - One of the best experts on this subject based on the ideXlab platform.
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NASA plans to take the boom out of Supersonic Flight
New Scientist, 2009Co-Authors: Jeff HechtAbstract:Sonic booms could be turned into rumbles with the results of NASA's latest Supersonic Flight tests
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NASA plans to take the boom out of Supersonic Flight
New Scientist, 2009Co-Authors: Jeff HechtAbstract:Sonic booms could be turned into rumbles with the results of NASA's latest Supersonic Flight tests. © 2009 Reed Business Information Ltd, England.
