D. Berdichevsky, J. M. R. Gómez, L. Vieira, A. Lago
{"title":"Validation of Novel Model for Identification of Thermal Conditions in the Low Corona","authors":"D. Berdichevsky, J. M. R. Gómez, L. Vieira, A. Lago","doi":"10.4236/aast.2022.71004","DOIUrl":"https://doi.org/10.4236/aast.2022.71004","url":null,"abstract":"","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70453689","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}
{"title":"Interference Detection and Suppression Based on Time-Frequency Analysis","authors":"Haijun Huang, K. Sun","doi":"10.4236/aast.2022.72006","DOIUrl":"https://doi.org/10.4236/aast.2022.72006","url":null,"abstract":"","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70453747","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 research paper discusses constructing a unified framework to develop a full-rate scheme for hypersonic heating calculations. The method uses a flow tracing technique with normal phase vector adjustment in a non-structured delineated grid combined with empirical formulations for convective heat transfer standing and non-standing heat flow engineering. This is done using dev-C++ programming in the C++ language environment. Comparisons of the aerodynamic thermal environment with wind tunnel experimental data for the Space Shuttle and Apollo return capsules and standing point heat transfer measurements for the Fire II return capsule was carried out in the hypersonic Mach number range of 6 - 35 Ma. The tests were carried out on an 11th Gen Intel(R) Core(TM) i5-1135G7 processor with a valuable test time of 45 mins. The agreement is good, but due to the complexity of the space shuttle tail, the measurements are still subject to large errors compared to wind tunnel experiments. A comparison of the measured Fire-II return capsule standing-point heat values with the theory for calculating standing-point heat fluxes simulated using Fay & Riddell and wind tunnel experiments is provided to verify the validity of this procedure for hypersonic vehicle heat transfer prediction. The heat fluxes assessed using this method for different aerodynamic profiles of hypersonic vehicles agree very well with the theoretical solution.
{"title":"Prediction of Aerothermal Environment and Heat Transfer for Hypersonic Vehicles with Different Aerodynamic Shapes Based on C++","authors":"Tian Huang, G. He, Qi Wang","doi":"10.4236/aast.2022.73008","DOIUrl":"https://doi.org/10.4236/aast.2022.73008","url":null,"abstract":"This research paper discusses constructing a unified framework to develop a full-rate scheme for hypersonic heating calculations. The method uses a flow tracing technique with normal phase vector adjustment in a non-structured delineated grid combined with empirical formulations for convective heat transfer standing and non-standing heat flow engineering. This is done using dev-C++ programming in the C++ language environment. Comparisons of the aerodynamic thermal environment with wind tunnel experimental data for the Space Shuttle and Apollo return capsules and standing point heat transfer measurements for the Fire II return capsule was carried out in the hypersonic Mach number range of 6 - 35 Ma. The tests were carried out on an 11th Gen Intel(R) Core(TM) i5-1135G7 processor with a valuable test time of 45 mins. The agreement is good, but due to the complexity of the space shuttle tail, the measurements are still subject to large errors compared to wind tunnel experiments. A comparison of the measured Fire-II return capsule standing-point heat values with the theory for calculating standing-point heat fluxes simulated using Fay & Riddell and wind tunnel experiments is provided to verify the validity of this procedure for hypersonic vehicle heat transfer prediction. The heat fluxes assessed using this method for different aerodynamic profiles of hypersonic vehicles agree very well with the theoretical solution.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70453799","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 proposes a communication system for nanosatellite Earth observation preliminary design technique as useful tools for managing and improving various aspects of regional and national resources. Has been estimated and proposed a design process for the low Earth orbit nanosatellite communication system. In proposed paper on basis of structural optimization technique have been formulated and solved next goals: reviewed Earth observation systems and studied their design parameters, analyzed the on-board antennas design background and provided analytical estimations, such as design a passband quadrature phase shift keying transmitter and receiver in Simulink, was obtained a bit error rate curves by using a Simulink / MathWorks, generated an offset quadrature phase shift keying waveform and investigated their characteristics, observed and analyzed the diagrams, constellation, and the signal trajectories of quadrature phase shift keying according contemporary design concept. All this allows to propose innovative communication system design techniques applied for the nanosatellite category.
{"title":"Communication System for Nanosatellite Earth Observation","authors":"N. Zosimovych","doi":"10.4236/aast.2021.63010","DOIUrl":"https://doi.org/10.4236/aast.2021.63010","url":null,"abstract":"This paper proposes a communication system for nanosatellite Earth observation preliminary design technique as useful tools for managing and improving various aspects of regional and national resources. Has been estimated and proposed a design process for the low Earth orbit nanosatellite communication system. In proposed paper on basis of structural optimization technique have been formulated and solved next goals: reviewed Earth observation systems and studied their design parameters, analyzed the on-board antennas design background and provided analytical estimations, such as design a passband quadrature phase shift keying transmitter and receiver in Simulink, was obtained a bit error rate curves by using a Simulink / MathWorks, generated an offset quadrature phase shift keying waveform and investigated their characteristics, observed and analyzed the diagrams, constellation, and the signal trajectories of quadrature phase shift keying according contemporary design concept. All this allows to propose innovative communication system design techniques applied for the nanosatellite category.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48759688","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}
Jumping from place to place, replicating food, biological or mechanical parts or beaming up somebody, may not be fiction, rather an issue of practical implementation as shall be observed in this paper. Devices like transporter, food replicators or warp drive intrigue our imagination. This paper is intended to show that Jump drive is an issue of coordinate transformation. Changing location from planet X to planet Y does not necessarily require travelling a distance D connecting between the two planets. The theoretical knowledge of changing the location from coordinate X to coordinate Y exists; we do that in signal processing, but, we have not yet developed such a machine. The present paper shows the feasibility of jump drive; however, much work needs to be done on the implementation.
{"title":"Jump Drive, Replicators, Transporters, and Time Travel","authors":"Y. Segman","doi":"10.4236/aast.2021.63009","DOIUrl":"https://doi.org/10.4236/aast.2021.63009","url":null,"abstract":"Jumping from place to place, replicating food, \u0000biological or mechanical parts or beaming up somebody, may not be fiction, \u0000rather an issue of practical implementation as shall be observed in this paper. \u0000Devices like transporter, food replicators or warp drive intrigue our \u0000imagination. This paper is intended to show that Jump drive is an issue of \u0000coordinate transformation. Changing location from planet X to planet Y does not \u0000necessarily require travelling a distance D connecting between the two planets. \u0000The theoretical knowledge of changing the location from coordinate X to \u0000coordinate Y exists; we do that in signal processing, but, we have not yet \u0000developed such a machine. The present paper shows the feasibility of jump \u0000drive; however, much work needs to be done on the implementation.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41453854","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 research focuses on multiple facts regarding the earth gravity and the space mechanism, mainly on the solar systems including the Sun and the planets belonging to it. Our solar system consists of our star, the Sun, and everything bound to it by gravity based on Albert Einstein and Isaac Newton theories. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, dozens of moons, millions of asteroids, Comets and meteoroids [1]. Also, it will discuss about The Geocentric model and how scientifically proofed that the Earth is not orbiting the sun as it has a fixed position in the universe with the rotation around its axis and the sun is orbiting the Earth in one solar year. The output of the Geocentric model led to that the gravity is a feature generated by the planet itself to be measured reference to the weight granted to the matter.
{"title":"The Truth behind the Solar System in the Universe","authors":"Rami Ayoob","doi":"10.4236/aast.2021.63011","DOIUrl":"https://doi.org/10.4236/aast.2021.63011","url":null,"abstract":"This research focuses on \u0000multiple facts regarding the earth gravity and the space mechanism, mainly on the solar systems \u0000including the Sun and the planets belonging to it. Our solar system consists of \u0000our star, the Sun, and everything bound to it by gravity based on Albert \u0000Einstein and Isaac Newton theories. The planets are Mercury, Venus, Earth, \u0000Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, dozens of moons, millions of asteroids, Comets and \u0000meteoroids [1]. Also, it will discuss about The Geocentric model and how scientifically proofed \u0000that the Earth is not orbiting the sun as it has a fixed position in the universe \u0000with the rotation around its axis and the sun is orbiting the Earth in one \u0000solar year. The output of the Geocentric model led to that the gravity is a \u0000feature generated by the planet itself to be measured reference to the weight \u0000granted to the matter.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42857367","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 project of the space train MARSZUG intended for regular delivery of astronauts to Mars is considered. In the first stage of the flight, the astronauts with the help of the carrier rocket equipped with a chemical rocket engine are delivered to the international space station (ISS). To deliver astronauts from Earth’s orbit to Mars orbit, a space train design consisting of two rockets, which have superconductive magnetoplasma electric engine MARS, has been developed. For the first time, a combined propulsion system MARS-M has been developed for the train movement, allowing carrying out the pitching, yaw and rotation of the rocket. This greatly simplifies the rocket control system and increases its reliability. The energy source of the electric engines is a sliding solar panel made of gallium arsenide. Working substance to create reactive thrust of electrorocket engines—hydrogen is stored in a liquid state in the cryogenic tank located along the longitudinal axis of the rocket. In the nasal part of the front electric rocket, a shaft rotating in a superconductive bearing is located. The shaft has a cylindrical nozzle, on which with the help of docking units two takeoff-landing capsules TLC-1 and TLC-2 are installed with which help landing and takeoff from the surface of Mars is carried out. This allows astronauts to constantly stay during the flight under the influence of gravity. To refuel the space train with liquid hydrogen in the orbit of Mars, the design of a space refueler with a chemical rocket engine is developed. The developed space train is able to regularly deliver astronauts to the surface near the northern pole of Mars.
{"title":"MARSZUG—A Space Train for Regular Delivery of Astronauts onto Mars","authors":"A. Rubinraut","doi":"10.4236/AAST.2021.62007","DOIUrl":"https://doi.org/10.4236/AAST.2021.62007","url":null,"abstract":"A \u0000project of the space train MARSZUG intended for regular delivery of astronauts \u0000to Mars is considered. In the first stage of the flight, the astronauts with \u0000the help of the carrier rocket equipped with a chemical rocket engine are \u0000delivered to the international space station (ISS). To deliver astronauts from \u0000Earth’s orbit to Mars orbit, a space train design consisting of two rockets, \u0000which have superconductive magnetoplasma electric engine MARS, has been \u0000developed. For the first time, a combined propulsion system MARS-M has been \u0000developed for the train movement, allowing carrying \u0000out the pitching, yaw and rotation of the rocket. This greatly simplifies the \u0000rocket control system and increases its reliability. The energy source of the \u0000electric engines is a sliding solar panel made of gallium arsenide. Working \u0000substance to create reactive thrust of electrorocket engines—hydrogen is stored \u0000in a liquid state in the cryogenic tank located along the longitudinal axis of \u0000the rocket. In the nasal part of the front electric rocket, a shaft rotating in \u0000a superconductive bearing is located. The shaft has a cylindrical nozzle, on \u0000which with the help of docking units two takeoff-landing capsules TLC-1 and \u0000TLC-2 are installed with which help landing and takeoff from the surface of \u0000Mars is carried out. This allows astronauts to constantly stay during the \u0000flight under the influence of gravity. To refuel the space train with liquid \u0000hydrogen in the orbit of Mars, the design of a space refueler with a chemical \u0000rocket engine is developed. The developed space train is able to regularly \u0000deliver astronauts to the surface near the northern pole of Mars.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47462185","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 velocity–versus-time rundown curves from two experimental Ti-6Al-4V inertia friction welds were analysed and differentiated several times, to produce rotational acceleration, jerk, jounce (or snap), crackle and pop versus-times curves for each weld. Titanium alloys and their mechanical properties are known to be highly sensitive to strain rate as the material is deformed, though nothing has ever been considered in terms of the higher-order time-derivatives of position. These curves have been studied and analysed further, for a more complete understanding of the derivative trends. Rotational acceleration and jerk traces both display behavior patterns across the two welds as the part rotates under action from the flywheel. The rotational snap also displays a pattern in this derivative during the final approximately 0.5 s of welding, as the energy dissipates. Evidence of a distinct oscillatory pattern in the rotational crackle and pop terms was noted for one weld when differentiating over a larger time-base, though could not be replicated in the 2nd weld. The higher derivative curves allow distinction of different process regimes, indicating that inertial energy mostly influences the time-base of dynamically steady-state phase. Qualitative differences between initial energies are evident in higher derivatives.
{"title":"A Study of the Deformation Derivatives for a Ti-6Al-4V Inertia Friction Weld","authors":"R. Turner, N. Warnken, J. Brooks","doi":"10.4236/AAST.2021.62008","DOIUrl":"https://doi.org/10.4236/AAST.2021.62008","url":null,"abstract":"The \u0000velocity–versus-time rundown curves from two experimental Ti-6Al-4V inertia \u0000friction welds were analysed and differentiated several times, to produce \u0000rotational acceleration, jerk, jounce (or snap), crackle and pop versus-times \u0000curves for each weld. Titanium alloys and their mechanical properties are known \u0000to be highly sensitive to strain rate as the material is deformed, though \u0000nothing has ever been considered in terms of the higher-order time-derivatives \u0000of position. These curves have been studied and analysed further, for a more \u0000complete understanding of the derivative trends. Rotational acceleration and \u0000jerk traces both display behavior patterns across the two welds as the part \u0000rotates under action from the flywheel. The rotational snap also displays a \u0000pattern in this derivative during the final approximately 0.5 s of welding, as \u0000the energy dissipates. Evidence of a distinct oscillatory pattern in the \u0000rotational crackle and pop terms was noted for one weld when differentiating \u0000over a larger time-base, though could not be replicated in the 2nd weld. The higher derivative curves allow \u0000distinction of different process regimes, indicating that inertial energy mostly influences the time-base of dynamically steady-state phase. Qualitative differences \u0000between initial energies are evident in higher derivatives.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41297947","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 sizing of the Electrical Insulation System (EIS) is an important challenge in electric motors of higher specific power driven by faster inverters. That keeps increasing the electric stress which the winding is submitted in the stator slot. Consequently, Partial Discharges (PD) are more likely to occur. Nowadays, the Paschen’s criterion is widely used to evaluate the risk of partial discharge. It requires the knowledge of electric field lines. This paper presents a method to precisely compute the electric field lines in a two-dimensional (2D) electrostatic problem. The field of study is composed of two magnet wires in close contact. Such configuration is representative of the turn-to-turn interaction in an electric motor slot. The problem is solved using the scalar potential formulation only. The notion of flux tubes is used for the post process of the electric field lines in a developed numerical code on Matlab. The developed method is compared to a ballistic method already included on Matlab. The work presented here is included in an automatic tool to suppress or reduce the partial discharge risk in a stator slot of high power density motor destined for future transportation systems.
{"title":"A General Method to Compute the Electric Flux Lines between Two Magnet Wires in Close Contact and Its Application for the Evaluation of Partial Discharge Risks in the Slots of Electric Machines Embedded in Future Transportation Systems","authors":"P. Collin, D. Malec, Y. Lefèvre","doi":"10.4236/AAST.2021.61003","DOIUrl":"https://doi.org/10.4236/AAST.2021.61003","url":null,"abstract":"The sizing of the Electrical Insulation System (EIS) is an important \u0000challenge in electric motors of higher specific power \u0000driven by faster inverters. That keeps increasing the electric stress which the winding is submitted in the stator \u0000slot. Consequently, Partial Discharges (PD) are more likely to occur. Nowadays, the Paschen’s criterion is widely used to \u0000evaluate the risk of partial discharge. It requires the knowledge of electric field lines. This paper presents a method \u0000to precisely compute the electric field lines in a two-dimensional (2D) \u0000electrostatic problem. The field of study is composed of two magnet wires in \u0000close contact. Such configuration is representative of the turn-to-turn interaction in an electric motor slot. The problem \u0000is solved using the scalar potential formulation only. The notion of flux tubes \u0000is used for the post process of the electric field lines in a developed numerical code on Matlab. The \u0000developed method is compared to a ballistic method already included on Matlab. \u0000The work presented here is included in an automatic tool to suppress or reduce \u0000the partial discharge risk in a stator slot of high power density motor destined for future transportation systems.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46438858","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}
Aircraft engine is an important guarantee for aircraft safety, and its failure mode and health management have become the top priority. However, there are very few researches on aircraft engine health management. This article mainly summarizes the current research status of aircraft engine health management (EHM) from the aspect of aircraft electronic system, focuses on the overall structure, functional areas and key technologies of EHM system design, points out the design requirements of EHM system, and finally proposes EHM system. The design must improve the monitoring accuracy of the sensor to meet the monitoring requirements of more than 0.1%. High-precision monitoring data is more conducive to engine fault detection and processing, and EHM will therefore develop in the direction of real-time, intelligent, integrated and networked.
{"title":"Design Technology Research of Aircraft Engine Health Management (EHM) Technologies","authors":"Wessam Abousada","doi":"10.4236/AAST.2021.61002","DOIUrl":"https://doi.org/10.4236/AAST.2021.61002","url":null,"abstract":"Aircraft engine is an important guarantee for aircraft \u0000safety, and its failure mode and health management have become the top \u0000priority. However, there are very few researches on aircraft engine health management. This article mainly summarizes \u0000the current research status of aircraft engine health management (EHM) from the \u0000aspect of aircraft electronic system, focuses on the overall structure, \u0000functional areas and key technologies of \u0000EHM system design, points out the design requirements of EHM system, and \u0000finally proposes EHM system. The design must improve the monitoring accuracy of the sensor to meet \u0000the monitoring requirements of more than 0.1%. High-precision monitoring data \u0000is more conducive to engine fault detection and processing, and EHM will \u0000therefore develop in the direction of real-time, intelligent, integrated and networked.","PeriodicalId":61930,"journal":{"name":"航空科学与技术(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41254728","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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