Sixth Pegasus-AIAA
Student Conference
Sevilla (Spain), April 29, 2010
Session:APaper:1
Time:9:00:00 AM
Student Name:Michael Konvalinka
Institution:CTU Prague
Country:CZ
Paper Title:FEM Modal and Flutter Analysis of the G304S Glider
Paper link:
ABSTRACT
This paper provides information about FEM modeling of the G304S sport composite glider and its subsequent modal and flutter analysis. In the first part, the design of the geometric and FEM model including its control system is described. In the following part, natural frequencies and modal shapes are numerically determined for several model configurations. The last section deals with the calculation of aerodynamic damping coefficients and also evaluates the flutter resistance of the structure based on the "Means of Compliance with FAR 23.629, Flutter" regulation.
Session:APaper:2
Time:9:30:00 AM
Student Name:Carmine Capone
Institution:Uni. Napoli
Country:IT
Paper Title:Numerical Simulation of Fluid-Structure Interaction comparing SPH and ALE Approaches
Paper link:
ABSTRACT
Crash is an important research field not only regarding last time. One of the most important research sector of transport industry is crashworthiness that in the last year is becoming always more enclosure in design process of its product. Aerospace industry is very interested to find new solutions and designs that could assure best behavior during crash phenomena. Clearly this field of study can assure new important products, thought to be functionally and opportunely defined in project contests. This is synonymous of configuration respect but also innovation of design systems that act as crash innovations. In according to that, numerical and analytical studies are increasing about the best methods to simulate impacts: the dual purpose of the research interests is to tune innovative simulation techniques and optimizing airplane configuration in crashworthiness sphere. The following work describes two new important numerical methods based on FE analysis, performed to study impact phenomena: the investigation is focused on fluid-structure interaction and it faces two different approach for the formulation of fluid field. ALE and SPH approaches are used to simulate a water domain, in which a structural component impacts. To obtain the best comparison with experimental tests and to underline the advantages and disadvantages of the methods is the purpose of double formulation use.
Session:APaper:3
Time:10:00:00 AM
Student Name:Chiara Grappasonni
Institution:Uni. Roma
Country:IT
Paper Title:Development of Operational Modal Analysis Methodologies for Dynamical Identification of Vega Lunch-Vehicle Subsystems
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ABSTRACT
The main objective of this paper is the development of methodologies able to estimate the dynamical behaviour of a structure undergoing its operative conditions. An overview of four different approaches, representing the actual state of the art in the research field of the Operational Modal Analysis, is provided along with the improvements suggested for damping ratios computing. The Frequency Domain Decomposition and Hilbert Transform methods compared to the Stochastic Subsystem Identification both in time and in frequency domain has been applied for modal identification on some subsystems of Vega launch vehicle: the Solid Rocket Motor of the first stage, P80, during the qualification firing test and the tank of the upper module, AVUM, during the vibration bench tests.
Session:APaper:4
Time:10:30:00 AM
Student Name:Benjamin Greiner
Institution:Uni. Stuttgart
Country:DE
Paper Title:Operational Modal Analysis and its Application for SOFIA Telescope Assembly Vibration Measurements
Paper link:
ABSTRACT
This paper deals with the application of Operational Modal Analysis for vibration measurements of the Telescope Assembly of the Stratospheric Observatory For Infrared Astronomy (SOFIA). Operational Modal Analysis acquires information about the dynamic characteristics of a structure in terms of eigenfrequencies, damping and mode shapes, without the need for explicit measurement of the vibration inducing loads. Since the exact influence of aerodynamic disturbance loads during operational flight conditions is not measurable, the Operational Modal Analysis approach is a promising contribution the SOFIA optimization effort. Although no measurements could be conducted during actual flight conditions within the scope of the study, the study shows that the approach of Operational Modal Analysis is feasible for the optimization process of the telescope. Two major techniques used in Operational Modal Analysis – Frequency Domain Decomposition and Stochastic Subspace Identification – are discussed with respect to their mathematical concept. The paper also presents the work done in preparation of future measurements by the definition of instrument configuration files and the design of a data format conversion tool.
Session:APaper:5
Time:11:30:00 AM
Student Name:Petr Novacek
Institution:CTU Prague
Country:CZ
Paper Title:The Attitude Estimation using IMU/GPS and Adaptive Filtering
Paper link:
ABSTRACT
This paper deals with the GPS usage for the attitude determination and IMU/GPS integration. GPS system is widely used as the source of position, velocity, and time information; however there is also other possibility of its usage which is the attitude determination capability. Several possible methods to determine GPS based attitude are presented after an introduction. The last presented method is closely described with appropriate hardware equipment. The GPS based attitude measurement results are presented later on. The last part describes the integration of IMU and GPS as a potential future development.
Session:APaper:6
Time:12:00:00 PM
Student Name:Javier Mateo Bonilla, José Rodríguez Morales
Institution:ESI Sevilla
Country:ES
Paper Title:Light System’s Controller
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ABSTRACT
Nowadays, every aeroplane’s light is controlled by means of individual switches. Since planes need to use multiple lights, it requires setting a high number of switches in the cockpit, and a remarkable level of attention from the pilot. The system we propose simplifies this action. The pilot will just need to push a single button to change from one light configuration to another automatically.
Session:APaper:7
Time:12:30:00 PM
Student Name:Juan Baena Castillo, María del Carmen Anton
Institution:ESI Sevilla
Country:ES
Paper Title:Lab view Simulation of ILS (Instrumental Landing System)
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ABSTRACT
This paper presents an ILS-DME simulation development with a graphical programming for measurement and automation, called Labview. ILS-DME is a ground-based instrument approach
system that provides precision guidance to an aircraft approaching and landing on a runway. This simulation shows the principal displays for the approach to the runway, and it intends to show the information that a pilot receives on his screen. With this information an aircraft will be able to land at the airport in spite of bad meteorological conditions. This simulation is based at the Seville´s airport, using real dates; but it will be able to be used at any other airport.
Session:APaper:8
Time:2:45:00 PM
Student Name:Yago Urroz
Institution:UPM Madrid
Country:ES
Paper Title:Hydrodynamic and Thermal Study of Biofilms for Aerospace Applications
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ABSTRACT
Application of bacterial biofilms as a thermal microbiosensor is an innovative procedure. Adhesion to brass surfaces with different roughness (0.5, 1, 2.5 and 3.75 μm) of Pseudomona putida biofilms was studied in situ, under variable flow conditions (Reynolds number was equal to 0, 60, 500 and 1000). In order to optimize the geometry of the experimental device, we have used a CFD software (SolidWorks combined with TermoFlo) that helped us to obtain a fully developed flow inside the channels. Besides, we tested a Proportional (P) Thermal Control System (TCS) and a Proportional Integral Differential one (PID) to guarantee a range of temperatures in the experimental equipment that assured the survival of the bacteria. The overall results emphasize the difficulty to obtain a uniform layer biofilm of Pseudomona putida on brass and its weakness when exposed to a water flow. An improvement in the growth technique of the biofilm on brass is thus necessary, e. g., providing nutrients during the whole growing process.
Session:APaper:9
Time:3:15:00 PM
Student Name:Gianfranco Laguardia
Institution:Politecnico Torino
Country:IT
Paper Title:ANALYSIS OF WSB TRANSFERS FOR AN EARTH-MOON SYSTEM FOR THE EUROPEAN STUDENT MOON ORBITER (ESMO) PROJECT
Paper link:
ABSTRACT
This paper presents the study performed at mission analysis level for the European Student Moon Orbiter (ESMO). The baseline transfer, selected for the flight to the Moon, exploits the Weak Stability Boundary (WSB) region of the Earth-Sun-Moon system. This study presents the trajectory design and the navigation analysis for the transfer of the target Moon orbit, explaining the reasons why this low-thrust transfer should be preferred compared to the other classical space transfers. The launch window analysis represents a key point of this study since the spacecraft will be launched as secondary payload and thus, the orientation of the initial GTO (Geostationary Transfer Orbit) will depend on the primary spacecraft. Furthermore, the survivability of the spacecraft at the Moon depends on the arrival geometry.
Session:APaper:10
Time:3:45:00 PM
Student Name:Marco Giannini
Institution:Politecnico Torino
Country:IT
Paper Title:Multi-Tethered Satellite Formations Dynamics
Paper link:
ABSTRACT
The dynamics of a rotating open multi-tethered satellite formation is here investigated, considering a model that includes the inertial properties of the cables in order to evaluate the dynamic evolution of the system under the action of gravity gradient force and tether tension. The results obtained for a simple, massless tether model are compared with those derived for a model where the tethers are modeled by means of a sequence of point-masses connected by massless springs and dampers ("bead model"). The analyses, performed by means of numerical simulation of the considered models, shows that the introduction of the tether lateral dynamics produces some little discrepancies wrt the massless model, especially in terms of elongations, that reflects on the deputies positions and could be of disturb for sub-millimetrical interferometric missions. Once the dynamic behavior of the formation is identi ed for the nominal values of
tether characteristics, a parametric analysis with respect to tether linear mass, damping and stiffness is also discussed starting assuming a linear variation of their values with tether cross
section.
Session:APaper:11
Time:4:45:00 PM
Student Name:Stefania Oliva
Institution:Politecnico Torino
Country:IT
Paper Title:Analysis of manned Earth-Moon missions
Paper link:
ABSTRACT
In this work we develop a tool for the fast evaluation of how variations of the design parameters change the masses of each phase and each module for an Earth-Moon manned mission. Starting from the study of NASA’s Constellation Program, we analyze the influence of the modifications of the height of the low lunar orbit, the choice of the propellant for each engine and the distribution of the ΔV, highlighting that only the last one is feasible and may produce advantages on the initial mass of the mission.
Session:APaper:12
Time:5:15:00 PM
Student Name:Frédéric Cristini
Institution:ISAE Toulouse
Country:FR
Paper Title:Satellite networks: a solution against emerging space threats
Paper link:
ABSTRACT
In addition to natural space environment hazards, space systems may be subject to emerging threats coming from the artificial space environment. The objective of our work is to design satellite systems being intrinsically threat-tolerant. Two different system architectures based on specialized networked small satellites are proposed: a "swarm constellation" architecture and a "networked constellation" architecture. Both are assessed through several operational criteria.
Session:APaper:13
Time:5:45:00 PM
Student Name:Roderik Koenders
Institution:TU Delft
Country:NL
Paper Title:Where to land on Mars: selecting the best landing site for the ExoMars mission
Paper link:
ABSTRACT
Only two nations have successfully achieved soft landings on the Moon or Mars: Russia and the United States of America. Europe wants to join this community in this decade by sending its own probe to the surface of Mars: ExoMars. An essential issue for the success of the mission is where to land. Landing-site selection is a process in which a diverse group of experts, which are often geographically distributed, need to find a location that minimizes the risk of failure during landing, and maximizes the chance of fulfilling the scientific and exploration goals of the mission. In this paper we identify the challenges facing Europe to select a safe, and scientifically interesting landing site for ExoMars, and propose several methods that will facilitate the process of landing-site selection for future missions.
Session:GPaper:1
Time:9:00:00 AM
Student Name:Pierluigi Della Vecchia
Institution:Uni. Napoli
Country:IT
Paper Title:AERODYNAMIC ANALYSIS AND OPTIMIZATION OF A REGIONAL TRANSPORT AIRCRAFT
Paper link:
ABSTRACT
The geometry of a typical regional transport aircraft is modified to reduce drag and improve performances, in particular cruise speed. Once performed a preliminary aerodynamic analysis on the original geometry, in order to detect those portions of the body shape whose modification mostly influences drag variation, an automatic procedure, manageable trough MATLAB, allows to modify those parts using interpolating curves and surfaces, respectively NURBS and NURBCOONS. Within the modification loop, each new geometry is analyzed trough a panel code solver until optimized shapes are found. Finally, the optimized body is exported into a CAD format (IGES) suitable for design and production. The optimization process has guaranteed a reduction of 3 percent of the total drag and an increase of 2 percent of cruise speed respect to the original configuration.
Session:GPaper:2
Time:9:30:00 AM
Student Name:Joost Venrooij
Institution:TU Delft
Country:NL
Paper Title:Understanding the role of the neuromuscular dynamics in biodynamic feedthrough problems
Paper link:
ABSTRACT
Biodynamic feedthrough (BDFT) refers to a phenomenon where accelerations cause involuntary limb motions which, when coupled to a control device, can result in unintentional control inputs. This study aims to increase the understanding of BDFT, and the role of the neuromuscular system (NMS) in particular. The fundamental question driving this research is how accelerations are transferred through the human body, i.e., through the NMS, and how the exact setting of the NMS influences this feedthrough. As the neuromuscular system differs from person to person and is highly adaptable, it is expected that BDFT does not only vary from person to person, but that also a single person can express a range of BDFT dynamics by adaptation of the neuromuscular settings. To investigate this hypothesis, use is made of the neuromuscular admittance, which describes the dynamic response of human limbs in response to force disturbances. A measurement method was developed to measure neuromuscular admittance and BDFT simultaneously. The results from this experiment confirm that the neuromuscular system plays such a large role in the occurrence of BDFT that the variability of the neuromuscular system cannot be ignored when investigating BDFT problems. Based on the experimental data a BDFT model was developed. The model parameters were estimated by fitting the model on the experimental data. The model successfully captures BDFT dynamics in both the frequency domain and the time domain, for different subjects and different settings of the neuromuscular system.
Session:GPaper:3
Time:10:00:00 AM
Student Name:Michael Mößner
Institution:TU Braunschweig
Country:DE
Paper Title:Training Algorithms based on Stabiiity Theories for Neural Flight Controllers
Paper link:
ABSTRACT
The idea of using neural network controllers in unmanned airplanes led to the demand of stable training algorithms. In this article the stability of the standard Gradient Descent training method is examined. Thereafter the Gradient Descent method is combined with the principle of Sliding Mode control which promises robustness and stability. The algorithms are implemented in a simulation environment with a neural network controlling structure which consists of a neural controller and a neural observer. The neural networks were trained online during a flight simulation. For the observer training the Sliding Mode Control algorithm obtained very good results.
Session:GPaper:4
Time:10:30:00 AM
Student Name:Alessandro Scola
Institution:AIAA section
Country:IT
Paper Title:Design of a quad-rotor mini Unmanned Air Vehicle (UAV)
Paper link:
ABSTRACT
Nowadays the development of small and mini Unmanned Air Vehicles (UAV) is an important topic both for military and civilian applications. A four rotary-wing UAV, named quad-rotor, has been studied and designed. In the design process the size of the quad-rotor and the geometrical properties of the structure were decided to withstand the imposed loads. After that, the on-board equipments as batteries, engines, propellers, engine speed controllers and the flight controller board were selected. Subsequently, the mathematical model, describing the flight dynamics of mini quad-rotor, was developed. In conclusion, as work verification, the hover manoeuvre was simulated.
Session:GPaper:5
Time:11:30:00 AM
Student Name:Juan Tendero
Institution:UPM Madrid
Country:ES
Paper Title:Optimization of Flight Profile to Minimize Fouling in Helicopter Gas Turbine Engines
Paper link:
ABSTRACT
The present research is the first attempt to optimize helicopter flight profiles taking compressor fouling into account. The main effects of particle ingestion in a gas turbine engine are a substantial reduction of the engine life and a significant deterioration of engine performance. In order to achieve the objectives, it is necessary to understand both the degradation mechanisms and the way to reduce them. This paper concludes that there is an altitude between 1,000 and 1,500 m, which minimizes degradation with the lowest impact on the flight time. In this region, particles can not be completely eliminated, thus filters and washing must be still used. This is the first step in the assessment of this aim and some areas need further work to be fully understood.