cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7509242.v1
title: Interannual Variability of Precipitation for the Centro de Lançamento de Alcântara in ENSO-Neutral Years

description: ABSTRACT: The interannual variability of precipitation in El Niño/Southern Oscillation-neutral years was studied for the Centro de Lançamento de Alcântara region. Monthly precipitation, sea surface temperature, wind at 925 hPa and outgoing longwave radiation data from various gridded datasets for the 1951-2010 period (60 years) were used. The data grouping was based on terciles. For the Centro de Lançamento de Alcântara in El Niño/Southern Oscillation-neutral years, March is the month of the rainy quarter (March to May) when the interhemispheric gradient of the sea surface temperature anomalies over the Atlantic (GRAD) and the atmospheric circulation at 925 hPa over the Centro de Lançamento de Alcântara were able to best explain the variability of precipitation. In this month, the wind direction at 925 hPa was the factor that explained the highest fraction of precipitation variance (40%), followed by GRAD (30%) and the wind magnitude (20%). For the Centro de Lançamento de Alcântara, in general, above-average precipitation was related to weak north-northeasterly low-level winds and southward GRAD, while below-average precipitation was related to strong east-northeasterly low-level winds and northward GRAD. These features were related to an eastward expansion of the Amazon convection towards the northern Northeast Brazil and might be related to a slight southward displacement of the Intertropical Convergence Zone in above-average precipitation years.
DOI: 10.6084/m9.figshare.7506464.v1
title: Thermoelectric-Sourced Programmable Electronic Switching Module to Ignite Electro-Explosive Devices

description: ABSTRACT: A microcontroller-based programmable electronic switching module is designed and developed. For supplying power to this module, thermoelectric generators (TEGs) are electrically integrated to the switching module. This integrated switching module is carried out to develop a Thermoelectric-sourced Programmable Electronic Switching Module (TPESM), which has many applications in the defence, space and many other fields. This module can also be used to charge batteries and to operate some microelectronic devices. The main objective of this paper was to use the available heat sources in armament stores for some needful applications. This module was successfully developed and proved to ignite electro-explosive devices (EED) at pre-programmed timing using programmable electronic switching module, which operates by the generated voltage of TEG. This paper discusses the applications, development, operation, experiments and results of this module.
DOI: 10.6084/m9.figshare.7506464
title: Thermoelectric-Sourced Programmable Electronic Switching Module to Ignite Electro-Explosive Devices

description: ABSTRACT: A microcontroller-based programmable electronic switching module is designed and developed. For supplying power to this module, thermoelectric generators (TEGs) are electrically integrated to the switching module. This integrated switching module is carried out to develop a Thermoelectric-sourced Programmable Electronic Switching Module (TPESM), which has many applications in the defence, space and many other fields. This module can also be used to charge batteries and to operate some microelectronic devices. The main objective of this paper was to use the available heat sources in armament stores for some needful applications. This module was successfully developed and proved to ignite electro-explosive devices (EED) at pre-programmed timing using programmable electronic switching module, which operates by the generated voltage of TEG. This paper discusses the applications, development, operation, experiments and results of this module.
DOI: 10.6084/m9.figshare.7509395
title: An Analytic Model for Dispersion of Rocket Exhaust Clouds: Specifications and Analysis in Different Atmospheric Stability Conditions

description: ABSTRACT: This paper brings the first results concerning a new analytic model to evaluate atmospheric dispersion in rocket launch scenarios, namely Generalized Integral Laplace Transform Technique for Rocket effluent dispersion model. The model is constituted by three different modules, being two pre-processors (micrometeorological parameters and deposition parameters) and the dispersion program. The dispersion calculations are made through the Generalized Integral Laplace Transform Technique solution of the two-dimensional, time-dependant, advectiondiffusion-deposition equation. The results show a set of simulations using data from the Chuva Project from the Centro de Lançamento de Alcântara for both stable and unstable planetary boundary layers, in order to evaluate model performance and illustration.
DOI: 10.6084/m9.figshare.7509395.v1
title: An Analytic Model for Dispersion of Rocket Exhaust Clouds: Specifications and Analysis in Different Atmospheric Stability Conditions

description: ABSTRACT: This paper brings the first results concerning a new analytic model to evaluate atmospheric dispersion in rocket launch scenarios, namely Generalized Integral Laplace Transform Technique for Rocket effluent dispersion model. The model is constituted by three different modules, being two pre-processors (micrometeorological parameters and deposition parameters) and the dispersion program. The dispersion calculations are made through the Generalized Integral Laplace Transform Technique solution of the two-dimensional, time-dependant, advectiondiffusion-deposition equation. The results show a set of simulations using data from the Chuva Project from the Centro de Lançamento de Alcântara for both stable and unstable planetary boundary layers, in order to evaluate model performance and illustration.
DOI: 10.6084/m9.figshare.7513076
title: A Novel Integrated Guidance and Control System Design in Formation Flight

description: ABSTRACT: Bird's formation flight is one of the best types of cooperation in nature. The bird's flight was the motivation of humans for flying. After one century of flight development, bird's formation flight was the motivation of humans for aircraft's formation flight. The closeness of aircrafts in formation flight and the effect of disturbances such as vortex make the formation flight control a challenging issue for control designers. This paper introduces a novel integration between guidance commands and system controller inputs. In recent papers the control system inputs were derived from approximate equations, and this approximation caused maneuver limitation. To tackle this problem, a new method is introduced, which employs proportional-integral-derivative (PID) controller in the integration block. This integrated guidance and control system employs the pure pursuit guidance to determine the unmanned aerial vehicle's acceleration command. A two-loop dynamic inversion technique is used for designing attitude and velocity controller, while the acceleration feedback control is used between the guidance system and attitude controller, which leads to increase in maneuverability of unmanned aerial vehicle's formation flight. The simulation results show that the proposed method can control the UAV's formation with sufficient accuracy in severe maneuvers.
DOI: 10.6084/m9.figshare.7513076.v1
title: A Novel Integrated Guidance and Control System Design in Formation Flight

description: ABSTRACT: Bird's formation flight is one of the best types of cooperation in nature. The bird's flight was the motivation of humans for flying. After one century of flight development, bird's formation flight was the motivation of humans for aircraft's formation flight. The closeness of aircrafts in formation flight and the effect of disturbances such as vortex make the formation flight control a challenging issue for control designers. This paper introduces a novel integration between guidance commands and system controller inputs. In recent papers the control system inputs were derived from approximate equations, and this approximation caused maneuver limitation. To tackle this problem, a new method is introduced, which employs proportional-integral-derivative (PID) controller in the integration block. This integrated guidance and control system employs the pure pursuit guidance to determine the unmanned aerial vehicle's acceleration command. A two-loop dynamic inversion technique is used for designing attitude and velocity controller, while the acceleration feedback control is used between the guidance system and attitude controller, which leads to increase in maneuverability of unmanned aerial vehicle's formation flight. The simulation results show that the proposed method can control the UAV's formation with sufficient accuracy in severe maneuvers.
DOI: 10.6084/m9.figshare.7506305
title: Numerical Study of the b-Ξ Flame Wrinkling Combustion Model in Oracles Test Rig

description: ABSTRACT: Numerical modeling of premixed combustion is important for a wide range of machines and systems focusing on compliance with the increasing pollutants reduction requirements. However good industrial numerical combustion models need a practical requiring, in this way, a balance between speed and accuracy. The flamelet models are suitable for this purpose providing a decoupling of the reactive and fluid dynamic problems, and an important model of this family is the b-Ξ flame surface wrinkling model. A specially challenging experiment to test this combustion model is the ORACLES test rig whose two independent parallel inlet channels consistently influence the turbulent combustion, injecting fuel and oxydizer at different equivalence ratios. The b-Ξ flamelet combustion model is known by the sensibility to numerical schemes and boundary conditions and, based on this, the present study proposes to investigate the coupling with the important SST k-ω turbulence model and achieve good balance among accuracy, boundedness, stability and efficiency using the ORACLES experiment.
DOI: 10.6084/m9.figshare.7506305.v1
title: Numerical Study of the b-Ξ Flame Wrinkling Combustion Model in Oracles Test Rig

description: ABSTRACT: Numerical modeling of premixed combustion is important for a wide range of machines and systems focusing on compliance with the increasing pollutants reduction requirements. However good industrial numerical combustion models need a practical requiring, in this way, a balance between speed and accuracy. The flamelet models are suitable for this purpose providing a decoupling of the reactive and fluid dynamic problems, and an important model of this family is the b-Ξ flame surface wrinkling model. A specially challenging experiment to test this combustion model is the ORACLES test rig whose two independent parallel inlet channels consistently influence the turbulent combustion, injecting fuel and oxydizer at different equivalence ratios. The b-Ξ flamelet combustion model is known by the sensibility to numerical schemes and boundary conditions and, based on this, the present study proposes to investigate the coupling with the important SST k-ω turbulence model and achieve good balance among accuracy, boundedness, stability and efficiency using the ORACLES experiment.
DOI: 10.6084/m9.figshare.7518716
title: Interaction Between Motions of Robotic Manipulator arms and the Non-Fixed base in On-Orbit Operations

description: ABSTRACT: The objective of this paper is to study the problem of the robotic manipulator operating on a non-fixed base by considering two dynamics scenarios. One in which the base is free to react in response to the robotic manipulator motion and the other in which the robotic manipulator moves its links in such a way to compensate the reaction forces on the platform so as to keep it stable. This approach is passive in the sense that no additional control effort has to be done to compensate the effects of the reaction forces on the platform. The methodology to approach the problem includes lab experiments aiming the dynamics analysis of a robotic manipulator operating on an ice platform on a glass table. The mathematical model of a satellite like a robotic manipulator is developed and then implemented in a computer by using the MATLAB software environment. The results of the computer simulations confirm that the control effort for the attitude control is larger for the case in which the links are in operation compared to the case in which the robotic manipulator is not working. For the passive case, the results confirm the attitude stability of the robotic manipulator platform when it is working. The passive case is that in which the robotic manipulator links are moving in a synchronized configuration and in a reverse sense.
DOI: 10.6084/m9.figshare.7518716.v1
title: Interaction Between Motions of Robotic Manipulator arms and the Non-Fixed base in On-Orbit Operations

description: ABSTRACT: The objective of this paper is to study the problem of the robotic manipulator operating on a non-fixed base by considering two dynamics scenarios. One in which the base is free to react in response to the robotic manipulator motion and the other in which the robotic manipulator moves its links in such a way to compensate the reaction forces on the platform so as to keep it stable. This approach is passive in the sense that no additional control effort has to be done to compensate the effects of the reaction forces on the platform. The methodology to approach the problem includes lab experiments aiming the dynamics analysis of a robotic manipulator operating on an ice platform on a glass table. The mathematical model of a satellite like a robotic manipulator is developed and then implemented in a computer by using the MATLAB software environment. The results of the computer simulations confirm that the control effort for the attitude control is larger for the case in which the links are in operation compared to the case in which the robotic manipulator is not working. For the passive case, the results confirm the attitude stability of the robotic manipulator platform when it is working. The passive case is that in which the robotic manipulator links are moving in a synchronized configuration and in a reverse sense.
DOI: 10.6084/m9.figshare.7519175
title: Operation Efficiency Assessment Model of Route Network in Terminal Area

description: ABSTRACT: Terminal area is an important part of airspace system. Its operation efficiency is related to the safety, order and efficiency of the entire air traffic. So the assessment of the terminal route network operation efficiency is needed. Considering the aspects of route segment capacity, flight flow, workload and operation stability, the paper analyzes the influent factors on the operation efficiency of terminal area route network, constructs the calculation parameters of operating efficiency, and establishes the calculation model of operating efficiency of the route segment. An assessment model for the operation efficiency of terminal area route network based on flight demand is built using comprehensive weighted method. Finally, the feasibility of the assessment model is verified by analyzing a case. The model can be used to assess not only the operation efficiency of a single route segment based on different flight demands in the terminal area, but also the real-time efficiency of the terminal area route network.
DOI: 10.6084/m9.figshare.7519175.v1
title: Operation Efficiency Assessment Model of Route Network in Terminal Area

description: ABSTRACT: Terminal area is an important part of airspace system. Its operation efficiency is related to the safety, order and efficiency of the entire air traffic. So the assessment of the terminal route network operation efficiency is needed. Considering the aspects of route segment capacity, flight flow, workload and operation stability, the paper analyzes the influent factors on the operation efficiency of terminal area route network, constructs the calculation parameters of operating efficiency, and establishes the calculation model of operating efficiency of the route segment. An assessment model for the operation efficiency of terminal area route network based on flight demand is built using comprehensive weighted method. Finally, the feasibility of the assessment model is verified by analyzing a case. The model can be used to assess not only the operation efficiency of a single route segment based on different flight demands in the terminal area, but also the real-time efficiency of the terminal area route network.
DOI: 10.6084/m9.figshare.7514993.v1
title: A Review on Aerodynamics of Non-Flapping Bird Wings

description: ABSTRACT Birds are known for their agility, manoeuvrability, and flexibility during flight. These features allow their ability to fly under a large range of flight conditions. Bio flyers and bio aerodynamic/fluid surfaces have inspired many to perform experiments and simulations as well as to relate their results to engineering applications. Wings specifically have been the most inspirational element. Aerodynamic forces, structure, unsteady flow, fluid-structure interaction, flow control, flow adaptive elements and mechanisms, flow vortices, flapping mechanisms, and hovering flight of birds are examples of research interests. This paper presents an overview of prior analyses and experiments on the aerodynamic performance and mechanical properties of birds in steady non-flapping flight.
DOI: 10.6084/m9.figshare.7514993
title: A Review on Aerodynamics of Non-Flapping Bird Wings

description: ABSTRACT Birds are known for their agility, manoeuvrability, and flexibility during flight. These features allow their ability to fly under a large range of flight conditions. Bio flyers and bio aerodynamic/fluid surfaces have inspired many to perform experiments and simulations as well as to relate their results to engineering applications. Wings specifically have been the most inspirational element. Aerodynamic forces, structure, unsteady flow, fluid-structure interaction, flow control, flow adaptive elements and mechanisms, flow vortices, flapping mechanisms, and hovering flight of birds are examples of research interests. This paper presents an overview of prior analyses and experiments on the aerodynamic performance and mechanical properties of birds in steady non-flapping flight.
DOI: 10.6084/m9.figshare.7510826
title: Applicability of FT-IR Techniques and Goniometry on Characterization of Carbon Fiber Surfaces

description: ABSTRACT Carbon fibers have been widely used as structural reinforcement in aeronautical composites, because of their exceptional mechanical properties. However, carbon fibers present few polar groups on their surfaces inducing a weak interaction with some thermosetting and thermoplastic matrices. Surface treatments, such as thermal and electrochemical oxidation, are generally followed by sizing in order to improve interfacial adhesion between carbon fibers and some matrices. The precise surface characterization, by means of its chemical groups and radical identification, has been pointed out as an effective tool of carbon fibers finishing assessment process. Goniometry and Fourier transforminfrared spectroscopy are widely used to characterize some materials applied in industry, but not for carbon fibers, mainly because of their filamentary shape and the high concentration of carbon even in their near surface. In this paper, unsized and sized Torayca T300 carbon fibers were characterized by goniometry tests to evaluate hydrophilic or hydrophobic character. Qualitatively, it was noticed the effect of sizing on carbon fibers by their hydrophilic behavior, which has not been observed in unsized samples. Chemical analysis was performed by Fourier transform-infrared spectroscopy using different setups: photoacoustic, attenuated total reflectance and universal attenuated total reflectance. The Fourier transform-infrared spectroscopy/attenuated total reflectance/Germanium was shown to be the most promising technique to analyze carbon fibers surface, despite the low level of relative intensities of some bands. By this technique, it was possible to observe differences between unsized and sized carbon fibers spectra.
DOI: 10.6084/m9.figshare.7510826.v1
title: Applicability of FT-IR Techniques and Goniometry on Characterization of Carbon Fiber Surfaces

description: ABSTRACT Carbon fibers have been widely used as structural reinforcement in aeronautical composites, because of their exceptional mechanical properties. However, carbon fibers present few polar groups on their surfaces inducing a weak interaction with some thermosetting and thermoplastic matrices. Surface treatments, such as thermal and electrochemical oxidation, are generally followed by sizing in order to improve interfacial adhesion between carbon fibers and some matrices. The precise surface characterization, by means of its chemical groups and radical identification, has been pointed out as an effective tool of carbon fibers finishing assessment process. Goniometry and Fourier transforminfrared spectroscopy are widely used to characterize some materials applied in industry, but not for carbon fibers, mainly because of their filamentary shape and the high concentration of carbon even in their near surface. In this paper, unsized and sized Torayca T300 carbon fibers were characterized by goniometry tests to evaluate hydrophilic or hydrophobic character. Qualitatively, it was noticed the effect of sizing on carbon fibers by their hydrophilic behavior, which has not been observed in unsized samples. Chemical analysis was performed by Fourier transform-infrared spectroscopy using different setups: photoacoustic, attenuated total reflectance and universal attenuated total reflectance. The Fourier transform-infrared spectroscopy/attenuated total reflectance/Germanium was shown to be the most promising technique to analyze carbon fibers surface, despite the low level of relative intensities of some bands. By this technique, it was possible to observe differences between unsized and sized carbon fibers spectra.
DOI: 10.6084/m9.figshare.7507754.v1
title: Finite Element Analysis of Pilot’s Helmet Design Using Composite Materials for Military Aircraft

description: ABSTRACT The objective of this research was to design pilot helmets and to perform analysis of designed ballistic helmet against impact strength of bullet in Solidworks and Laminator software. The material used for construction of the helmet is fiber reinforced polymer matrix composite in which polymer matrix is made of nylon, a thermoset resin, and the fibers are aramid, an aromatic polymide resin developed by E.I. duPont de Nemours and Company and sold under the trademarks “Kevlar®” and “Nomex®”. The design of the helmet is done by deciding the stacking sequence of various laminae which are oriented with main material directions at different angles to the global laminate axes in order to produce a structural element in the form of a shell. The simulation of the helmet in Solidworks and Laminator is done with an 8-g AK 47 bullet, hitting it with a velocity of 710 m/s. The model is validated against published data and a good correlation is observed. The result of this project is that a 1.30 kg helmet with shell thickness of 7 mm is obtained, which is economical, light weight and is able to give high-performance protection against ballistic shrapnel and bullets.