BOOK OF ABSTRACTS Eight Pegasus-AIAA Student Conference Poitiers (France), April 12, 2012 Session: A Paper: 1 Time: 11:00 AM Student Name: Christine Elisabeth Klei Institution: RWTH, Aachen Country: Germany Paper Title: Investigation of the Recirculation Region of a Generic Rocket Configuration using Stereoscopic PIV Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Klei_Aachen.pdf ABSTRACT Flow fields with high spatial and temporal dynamics form at the tail section of modern space transportation systems. Base drag, induced by separating flow regions, decisively influences total drag values. Wind tunnel experiments at subsonic flow conditions are carried out using a generic rocket model, simulating an early ascend period. In a first period, a reference model geometry without nozzle is investigated. Stereoscopic Particle Image Velocimetry is used to characterize three-dimensional structures of the recirculation area behind the model base. Discrepancies due to deflections in the angle of yaw are of special interest. Session: A Paper: 2 Time: 11:30 AM Student Name: Francesco Avallone and Carlo Salvatore Greco Institution: UniNA Federico II, Naples Country: Italy Paper Title: 2D inverse heat transfer measurements by IR thermography in hypersonic flows Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Avallone_uniNA.pdf ABSTRACT The purpose of this work is to develop a data reduction technique for the measurement of heat fluxes in hypersonic flows. If the temperature gradients in the solid are high enough (e.g. in case of Gӧrtler vortices that can have high spatial frequency), tangential conduction heat flux in the test model is not negligible. To estimate the heat flux it has been solved a 2-D inverse heat transfer problem in which, to reduce the computational cost, the heat flux distribution has been represented with discrete Fourier series. The data reduction technique has been numerically validated and then applied to experimental tests performed on a double compression ramp where the instability is generated using a comb-like strip and several campaign are performed at different pitches of the teeth. Tests are carried out in the HTFD (Hypersonic Test Facility Delft) hypersonic tunnel at Mach number equal to 7.5 and at unit Reynolds number equal to 6.61∙106 m-1. The heat flux obtained solving the 2-D inverse heat transfer problem is compared with the one obtained solving the 1-D problem to evaluate the effect of the tangential conduction. Session: A Paper: 3 Time: 12:00 AM Student Name: Diogo Camello Barros Institution: ENSMA, Poitiers Country: France Paper Title: Passive flow control around a wall-mounted finite cylinder Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/DiogoCamello_ENSMA.pdf ABSTRACT The present work relates the effect of a straight perturbation on a finite cylinder mounted over a wall. The aspect ratios studied (length/diameter) are 3 and 6 at Reynolds’ numbers Re of 5.104, 7.104 e 1.105. The influence of a trip wire on the vortex shedding frequencies and flows modifications generated by different aspect ratios has been analyzed. Averaged drag and lift coefficients have been measured and the existence of a critical position of the perturbation has been observed, in which the Strouhal number St and the coefficients vary substantially. Non-stationary efforts coupled with the fluctuant pressure field on the wall have been measured. The results show an important correlation between efforts and pressures. The POD (Proper Orthogonal Decomposition) has been used for the reconstruction of the pressure field and the EPOD (Extended Proper Orthogonal Decomposition) have pointed the correlated part of the efforts with the pressure signals. It has been observed that the aspect ratio introduces important differences in the efforts and pressures measures, changing the recirculation zone around the cylinder. The position of the perturbation changes significantly the vortex shedding frequency and the mean values of the forces. The energy of the proper modes and the extended ones shows that a reconstruction of the pressure or effort field can be done by using two modes. Session: A Paper: 4 Time: 12:30 AM Student Name: Konstantinos Kourtzanidis Institution: ISAE, Toulouse Country: France Paper Title: Numerical Simulation of Plasma Actuators for Flow Control Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Kourtzanidis_ISAE.pdf ABSTRACT As flow control gains more and more interest amongst the aerospace research community, new methods are arising really fast. This paper deals with the application of plasma actuators to control the flow over a at surface or an airfoil and more precisely the numerical modelling of them and their effects in the flow. After a brief introduction to the subject, the models used for the plasma physics and its coupling with the flow are presented side by side with the meshing procedure. After validating the capability of the solver with simple cases, different aspects are being examined over a at plate case such as turbulence and compressibility and compared with experimental data. Moreover for the same case, a parametric study has been performed for the actuator's inputs as well as a study on its effects on the laminar to turbulent transition. The actuator has been modelled also on an airfoil so that more interesting results could be obtained and presented. The mesh generation and solver's parameters are presented separately for each section. Session: A Paper: 5 Time: 02:00 PM Student Name: Dewi Boucher and H. Guillot Institution: Ecole de l’Air, Salon de Provence Country: France Paper Title: Experimental drag polar of the F-16 Falcon using wind tunnel tests Paper link: http http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Boucher_EdA.pdf ABSTRACT The aerodynamics of the General Dynamics F-16 Falcon has been studied using experimental and theoretical methods. Subsonic wind tunnel tests on a 1/48 model of the F-16 were used to determine the lift and drag on the aircraft at several Mach numbers. The main objective was to determine the drag polar of the model in several low speed airstream velocities at a Mach number under 0.2 and then extrapolate the results to a higher Mach number. This experiment has been conducted with Aerolab wind tunnel of the San Jose State University Aerodynamics Department. The result of the experiments met the theoretical results of lift and drag on an F-16 fuselage. The performance of the F-16 is finally discussed using the results on the model. Session: A Paper: 6 Time: 02:30 PM Student Name: Filippo Palo Institution: PoliMI, Milano Country: Italy Paper Title: Wake Models for Real-Time Rotorcraft Simulation Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Palo_PoliMI.pdf ABSTRACT The capability of modelling and representing the wake of a rotorcraft is essential to properly simulate most of the flight conditions, if not all. The accurate representation of the rotor wakes is still a challenge; notwithstanding the constant increase of computer power, it is still impossible to perform a complete Free Wake simulation of helicopter rotor wakes in real time. This paper presents two different ways of tackling the problem, in which the wake model is separated from the inflow one. The first approach refers to models able to perform accurate analysis in steady flight, in which the wakes instantly fit to actual flight condition without memory of their previous configuration. In the second part of the work a dynamic model is formulated and implemented, termed FastFreeVortex (FFV) rotor wake model. It allows to perform manoeuvring flight analysis, while respecting the constraint of low computational request, since it may run in real-time on common desktop machines. The basic element of the FFV model is represented by a set of vortex rings which constitute the wake. Both models are described and then validated in several conditions: hover, forward flight, also in ground effect (IGE), and in descent flight, with particular attention to the ability to intercept the Vortex Ring State (VRS) condition. Session: A Paper: 7 Time: 03:00 PM Student Name: Diliana Dimitrov Institution: TU Dresden, Dresden Country: Germany Paper Title: Unsteady aerodynamics of wings with an oscillating flap in transonic flow Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Dimitrov_Dresden.pdf ABSTRACT Within the scope of this paper the behaviour of unsteady flow due to oscillating flaps on the airfoil NLR 7301 and the AFMP wing is analysed. For the two-dimensional model, the two flow solvers of DLR (TAU) and ONERA (elsA) are applied. Therefore, a comparison not only with experimental data but also among both CFD-results is carried out. Although it exists a good agreement for this two-dimensional experiment and the numerical solutions, differences in the turbulence models of the codes are exhibited. The three-dimensional delta wing is calculated using TAU. Surprisingly, the experimental data is only partly reproducible with the CFD code. Despite the existing discrepancies, the nature of unsteady flow due to an oscillating flap can be found in the experiment as well as in the numerical results. Session: A Paper: 8 Time: 04:00 PM Student Name: Kayo Galem Institution: TU Berlin, Berlin Country: Germany Paper Title: Analysis of Turbulence Accidents based on STAMP and Technical Concepts for Mitigation Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Galem_Berlin.pdf ABSTRACT Accidents that have resulted from turbulence encounters in scheduled airline flights within the US airspace between 2000 and 2010 were analyzed. A methodology based on STAMP was developed for this purpose in order to identify systemic factors in the causal mechanisms of accident occurrence. Limitations in the processes controlling the safety risk of bodily harm as the consequence of turbulence in flight operations were revealed by the analysis. Two technical concepts are proposed to achieve the effective mitigation of this safety risk. Session: A Paper: 9 Time: 04:30 PM Student Name: Katerina Petrekova Institution: CVUT, Prag Country: Czech Republic Paper Title: Design of the intelligent tutorial dialogue. New progressive methodology of ATC- controller training Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Petrekova_CVUT.pdf ABSTRACT The contribution paper deals with the possibility to design and project the new progressive intelligent communication system between the ATC-controllers and automatic computer pseudo- pilots for training purposes. This tutorial intelligent dialogue would be applied and consequently used in the current air traffic procedure systems and methodology of ATC-controllers’ training, aiming to improve and increase the level of their proficiency abilities, accuracy, and in general, overall total ATC-controller cadets’ work-scope readiness during training for the ATC-controller profession. Session: A Paper: 10 Time: 05:00 PM Student Name: Oleg Ieremeiev and Alexly Rubel Institution: KhAI, Kharkiv Country: Ukraine Paper Title: Method of estimating UAV flight horizontal velocity using video sequences Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Ieremeiev_Kharkiv.pdf ABSTRACT The task of estimating UAV flight velocity using video sequences obtained from on-board video camera is considered. A method for estimating displacement of X and Y coordinates for adjacent video frames based on finding similar blocks in two frames with taking into account their informativity is proposed. To provide an acceptable speed of the method, fast boundary clustering approach is applied. A test video sequence for verification of methods of motion estimation is formed. By comparative analysis with well-known methods, it is shown that the proposed method provides both the best accuracy of the estimates and the smallest number of abnormal estimates. Session: B Paper: 11 Time: 11:00 AM Student Name: Elsa Piollet Institution: ISAE, Toulouse Country: France Paper Title: Mistuning Criticity Assessment for Industrial Single-Piece Single- and Multi- Stage Bladed Assemblies Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Piollet_ISAE.pdf ABSTRACT The aim of the present work is to create a computation chain for multi-stage mistuning study in an industrial environment. Turbojet engine components are subject to vibration constraints that can lead to early failure. The need for improved performance with weight-reduced engines has led to new single-piece multi-stage architectures. Inter-stage couplings in single-piece multi-stage assemblies can modify the structure's sensitivity to variations in blade properties. These variations, known as mistuning, can lead to energy localization and early failure due to fatigue. The computation chain proposed assesses the criticity of random mistuning in industrial multi-stage bladed assemblies. It is integrated in the industrial software environment. The program is first validated on an academic case and then applied to an industrial case, leading the way for future criticity assessments. Session: B Paper: 12 Time: 11:30 AM Student Name: Alfonso Pagani e Matteo Filippi Institution: PoliTO, Torino Country: Italy Paper Title: Advanced Models for Static and Dynamic Analysis of Wing and Fuselage Structures Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Pagani_PoliTO.pdf ABSTRACT Recently, an hierarchical formulation based on the Carrera Unified Formulation (CUF) was introduced by adopting polynomial expansions of the displacement field above the cross-section of the structure. The finite element method was exploited to develop numerical applications by employing the principle of virtual displacements. In the CUF framework the finite element matrices and vectors are expressed in terms of fundamental nuclei whose forms do not formally depend on the order and the class of the model. Two classes of 1D higher-order models have been developed according to the CUF. The Lagrange Expansion (LE) models were built by means of four- (L4) and nine-point (L9) Lagrange-type polynomials. The Taylor Expansion (TE) models exploit N-order Taylor-like polynomials. The classical 1D models are obtained as special cases of TE. This paper proposes advanced 1D theories for static and dynamic analysis of aeronautical structures. A number of typical stiffened-shell structures were analyzed. Classical 1D (Euler-Bernoulli and Timoshenko) and refined models were implemented by exploiting the 1D CUF. Finite element models made with a commercial software were used for comparison purposes. Results have highlighted the enhanced capabilities of the present formulation which is able to detect solid and shell-like accuracies with significantly lower computational costs. Session: B Paper: 13 Time: 12:00 AM Student Name: Krystina Davtian and Vadim Garin Institution: KhAI, Kharkiv Country: Ukraine Paper Title: Problems of recycling constructional polymeric composite materials Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Davtian_Kharkiv.pdf ABSTRACT One of the main tendencies in development of aircraft, engineering, transport and other branches is wider usage of polymeric composite materials (PCM). In comparison with usual constructional materials polymeric composite materials have considerably higher performance at essentially less mass. Originally application of PCM in these fields was restrained considering their high cost, PCM design and manufacture issues as well as problems with attachment of structural units from PCM to metal parts of an airframe. While solving these problems and PCM cost reducing when organizing their mass production, application of these materials began to increase rapidly. Additional boost to PCM implementation in modern aircraft construction was growth of fuel cost. Airframe mass reduction provided with wide PCM application along with improvement of engine performance is the main direction of improving fuel efficiency. Intensive usage of composite materials in such branches of industry as transport, engineering and building has begun due to developing techniques of design and manufacturing of constructions from composite materials. It is favored by creation of large-tonnage manufactures of semi-finished products (threads, fabrics and prepregs), thus cost of composite materials is steadily reduced. The published forecasts of carbon fiber market growth show that world demand in 2020 can make up to 340 000 tons a year. At the price less than 10 US dollars per kilo the volume of world consumption of composite materials based on carbon fiber can rise up to 10 million tons a year in motor industry only. It makes PCM the main constructional materials of next technological mode. Despite obvious advantages of PCM use there is a problem constraining its wide application - recycling. The volume of recycling PCM by various estimations can reach 10...15 % from annual manufacture. This number includes both construction recycling and PCM wastes. Today in Europe wasters, carbon fiber debris, and other composite production wastes make up about 500 tons a year, and in the following 15 years it is necessary to recycle from 6000 to 8000 aircraft manufactured with PCM share in the airframe less than 20 % from total mass. Despite a great number of researches no efficient industrial PCM recycling techniques are developed so far. The problem is also complicated since many processes in development are connected with formation of highly toxic compounds. Therefore development of ecologically safe PCM recycling techniques remains a relevant one and is of practical importance. The purpose of the given paper is the analysis of modern PCM recycling methods and definition of advanced approaches for creation of ecologically safe techniques for their recycling. Session: B Paper: 14 Time: 12:30 AM Student Name: Iryna Gagauz Institution: KhAI, Kharkiv Country: Ukraine Paper Title: Investigation of Radiation Influence on Composite Materials Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Gagauz_Kharkiv.pdf ABSTRACT Composite materials are gained popularity in a number of industries due to its specific characteristics. Space industry is one of them where high stiffness, low coefficient of thermal expansion, and dimensional stability during the operational lifetime as well as minimum weight solution are required. But spacecraft is exposed to harsh conditions of outer space during the launch and operation. Properties of composite materials may change due to low earth orbit (LEO) space environment effect. The purpose of this work to investigate of radiation influence on composite materials that commonly used in aerospace industry to predict material behaviour in the space. Session: B Paper: 15 Time: 02:00 PM Student Name: Marc Neveu Institution: ISAE, Toulouse Country: France Paper Title: Mapping Trace Gases on Earth, Mars and Beyond with a Gas Correlation Radiometer Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Neveu_ISAE.pdf ABSTRACT We present results in the development of a miniaturized gas correlation radiometer (GCR), designed as an orbiting instrument for Earth and planetary science missions. This instrument will be capable of simultaneously mapping multiple gases in a planet's atmosphere. Gas correlation radiometry is a mature sensing technology on Earth; successful miniaturization makes it promising for trace gas measurements in the atmospheres of Mars, Venus, or Titan. The component that most impacts the size of a gas correlation radiometer is the gas correlation cell, the pathlength of which affects the sensitivity of the instrument. We use a hollow waveguide of pathlength equivalent to a 10-meter multipass cell previously flown on Earth orbit. This results in a cell mass and volume reduction greater than 99%. We present methane (CH4) and formaldehyde (CH20) measurements from our prototype GCR. This modular instrument can be expanded to measure additional species of interest, including water vapor (H20), deuterated water (HD0), nitrous oxide (N20), hydrogen sulfide (H2S), methanol (CH30H), sulfur dioxide (S02), and carbon dioxide (C02). We review the scientific interest and spectroscopic feasibility of mapping these gases on different planetary bodies. Session: B Paper: 16 Time: 02:30 PM Student Name: Stefania Soldini Institution: PoliMI, Milano Country: Italy Paper Title: Attitude Dynamics of ESMO Satellite Mass Expulsion Torques and Propellant Slosh Model Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Soldini_PoliMI.pdf ABSTRACT This paper deals with the Newton and Euler Dynamics Equations of ESMO, where a mathematical formulation has been developed. The purpose is to design the internal (non-environmental) disturbances of the spacecraft, by focusing our attention on the Mass Expulsion Torques and, primarily, on the Propellant Sloshing effect. Moreover, in order to have an accurate model of the spacecraft, the dynamics of the reaction wheels have been taken into account as they are part of the actuators system. A review of the Propellant Sloshing concepts has been investigated, but in this paper merely the 3D Spherical Pendulum Slosh Model is presented, the one which seemed to be the most consistent. Furthermore, the Mass Expulsion Torques effects have also been studied in order to estimate how they affect the attitude of ESMO. In addiction, a consumption model has been developed so as to estimate the total propellant waste. In that way the inertial properties of ESMO are not constants anymore and their terms become time depending within the equation of motion. The primarily interest focused on the internal dynamics since it has been intended to analyze their effect on the ESMO motion in both its orbit and the attitude dynamics. In the model studied, these two dynamics equations are uncoupled, in fact the environmental torques, which are usually taken as coupling terms, have not been considered. Session: B Paper: 17 Time: 03:00 PM Student Name: Chiara Finocchietti Institution: UniPI, Pisa Country: Italy Paper Title: Combining Low-Thrust and Manifold Dynamics for Vertical Lyapunov Orbits Missions Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Finocchietti_UniPI.pdf ABSTRACT With the aim at designing innovative space missions both in terms of operative orbits and transfer trajectories, this study deals with the Circular Restricted Three Body Problem and its applications. The vertical Lyapunov orbits, peculiar solutions of the model are computed together with the ballistic trajectories (manifolds) associated with them. Moreover, with the aim at designing low-fuel consumption transfer trajectories toward vertical Lyapunov orbits, the combination of the three body model dynamic and low-thrust transfer strategies is investigated. Finally, the optimization problem of the low-thrust transfer trajectory is considered and a direct multiple shooting method is presented for its solution. Session: B Paper: 18 Time: 04:00 PM Student Name: Tim Dackermann Institution: Uni Stuttgart, Stuttgart Country: Germany Paper Title: Numerical and Analytical Analysis of Voting and Monitoring Mechanisms for Different Configurations of Asynchronism Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Dackermann_Stuttgart.pdf ABSTRACT The processing of asynchronous redundant information is a basic approach in distributed Avionics and Flight Control Systems. However, due to asynchronous sampling redundant signals may deviate among each other and therefore result in unacceptably high monitoring limits for common voting and monitoring mechanisms. Advanced algorithms aim towards handling asynchronous data in a more sophisticated way but due to additional complexity the choice for an appropriate mechanism is not always straightforward. Thus, this paper introduces a model-based evaluation environment for the objective assessment of voting and monitoring mechanisms. For validation purposes the environment is verified via numerical and analytical analysis of a selected system architecture featuring asynchronism. Session: B Paper: 19 Time: 04:30 PM Student Name: Jakub Šimánek Institution: CVUT, Prague Country: Czech Republic Paper Title: Analyses of Suboptimal Models for INS/GPS Navigation Algorithms Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Simanek_CVUT.pdf ABSTRACT This paper analyses the fusion of an inertial navigation system (INS) and a global positioning system (GPS) based on various state space models implemented in an extended Kalman filter. A detailed analysis of navigation performance of three suboptimal INS/GPS models is presented. Navigation algorithms were implemented in the MATLAB environment and verified under laboratory conditions using a radio controlled car model with a precise reference trajectory as well as by field experiments using car navigation. Session: B Paper: 20 Time: 05:00 PM Student Name: Ondrej Teren Institution: CVUT, Prague Country: Czech Republic Paper Title: Angular rate reference system employing a fiber optic gyro Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Teren_CVUT.pdf ABSTRACT This paper discusses the design of an angular rate reference system. Having a precise angular rate available during a calibration process is a key issue and in majority cases also very expensive. There have to be used laser gyroscopes due to their high resolution and sensitivity, stable and low- level noise outputs. In our case the angular rate reference system uses a fiber optic gyro to determine an angular rate and also consequently an angle along the vertical axis. Furthermore, the system employs a dual axis accelerometer in cooperation with dual axis tilt sensor to measure a tilt of the system, which is crucial to compensate the Earth rotation sensed by the gyro. Session: C Paper: 21 Time: 11:00 AM Student Name: Klaus Seywald Institution: KTH, Stockholm Country: Sweden Paper Title: Wingbox Mass Prediction considering Quasi-Static Nonlinear Aeroelasticity Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Seywald_KTH.pdf ABSTRACT Nonplanar wing configurations promise a significant improvement of aerodynamic efficiency and are therefore currently investigated for future aircraft configurations. A reliable mass prediction for a new wing configuration is of great importance in preliminary aircraft design in order to enable a holistic assessment of potential benefits and drawbacks. In this thesis, a generic numerical modelling approach for unconventional wing configurations has been developed and a simulation tool for their evaluation and mass prediction is implemented. The wingbox is modelled with a nonlinear finite element beam which is coupled to different low-fidelity aerodynamic methods obtaining a quasi-static aeroelastic model that considers the redistribution of aerodynamic forces due to deformation. For the preliminary design of the wingbox various critical loading conditions according to the Federal Aviation Regulations are taken into account. The simulation tool is validated for a range of existing aircraft types. Additionally, two unconventional configurations, the C-wing and the box-wing, are analyzed. The outlook provides suggestions for extensions and further development of the simulation tool as well as possible model refinements. Session: C Paper: 22 Time: 11:30 AM Student Name: Falk Sachs Institution: TU Braunschweig, Braunschweig Country: Germany Paper Title: Development of a reconfiguration concept based on nonlinear inverse dynamics using artificial neural networks Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Sachs_Braunschweig.pdf ABSTRACT Different approaches of reconfiguration concepts for occurring actuator failures are presented. These are incorporated into a nonlinear control strategy based on feedback linearization in a cascaded design of three control loops. The inner loop is augmented with artificial neural networks (ANN), which counteract existing inversion errors and parameter uncertainties. As a demonstrator, an unmanned aircraft system (UAS) is chosen, which shows that the reconfiguration works reliably during fully automatic operation and therefore increases the robustness of existing controller. Further, the results underline, that the implementation of adaptive ANN in the controller architecture as well as in the reconfiguration scheme are effective steps to improve the reliability of fully automatic systems. Session: C Paper: 23 Time: 12:00 AM Student Name: Pedro Pablo Guerrero Vela Institution: ETSI, Seville Country: Spain Paper Title: Aero-Structural Airfoil Design Optimisation for Cruising Configuration using Tabu Search Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Guerrero_Vela_ETSI.pdf ABSTRACT Multi-Disciplinary Design Optimisation is the best approach for finding optimum solutions to real- world problems, where conflictive requirements from different nature converge. Thus, the optimisation of such systems represents a really challenging task from a technical point of view. In this paper, the development of a fully integrated automatic tool for continuous aero-structural wing design optimisation purposes will be introduced. Five different modules have been configured and interconnected to make the tool a reality, representing each of them a state-of-the-art application: a) Multi-Objective Tabu Search (MOTS) a stochastic optimiser enhanced with local search strategies, b) a parameterisation tool based on Free Form Deformation (FFD) techniques, c) flow analyser configured for automatic execution, d) in-house fluid-structure interface and e) structural analyser. An initial optimisation study of a simplified wing based on the Airbus Test Case-A airfoil has been performed. Two objective functions were assessed, these are: drag to lift coefficient and the maximum Von Mises stresses that appear at any point on the structure. The preliminary results reveal the potential of the tool for the successful bi-objective optimisation, demonstrating the integrity and functionality of the design tool. Outstanding improvements for both objective functions are found and three different solutions from the Pareto front are analysed and compared against the datum configuration. Session: C Paper: 24 Time: 12:30 AM Student Name: Agnieszka Kwiek Institution: WUT, Warsaw Country: Poland Paper Title: Initial optimization of the strake for the rocket plane Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Kwiek_Warsaw.pdf ABSTRACT This paper includes description and results of optimization process of strake shape. The calculations were conducted for rocket plane whose application will be space tourism. The main problem of the vehicle during the re-entry flight is a sink rate, in this case lift vortex will be prevent this phenomenon. The main purpose of this research is improving influence of vortex lift. The calculations were conducted by software which base on Euler system of equations and multi-grid scheme. The study focused on high angle of attack cases and subsonic flow. The optimization process focused on aspect of mechanic of flight, other design problems are omitted. Session: C Paper: 25 Time: 02:00 PM Student Name: Daniel Martinez Ruiz Institution: ETSIA, Madrid Country: Spain Paper Title: Mini-Helicon plasma thrusters source study Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Martinez_Ruiz_ETSIA.pdf ABSTRACT In this paper a summary of the energetic study of a mini-Helicon plasma thrusters is presented. Helicon thrusters are high plasma density - high efficiency devices which are a robust alternative to current Hall thrusters for long duration space missions. Helicon sources have been used in the past for material processing. Furthermore, this thrusters does not require a neutralizer for the exhaust flow, which increases its lifetime considerably. A study over the electromagnetic and fluid power requirement is carried out to get insight on the power transmission and validate the energetic viability of the source. Session: C Paper: 26 Time: 02:30 PM Student Name: Elena Roibàs Millàn Institution: ETSIA, Madrid Country: Spain Paper Title: Spatial properties of plasmas of low power ring cusp ion thrusters Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Roibas_Millan_ETSIA.pdf ABSTRACT The operation of a gridded, low power ring cusp ion plasma thrusters and the spatial properties of the emitted plasma plumes are investigated. In this small (5 cm diameter) model, the primary plasma is produced by a low pressure electric discharge and thermo-ionic electron emitters are employed for ion beam neutralization. This replaces the currently employed hollow cathodes. This would allow to decrease the payload weight and the amount of neutral gas used as propellant. The experimental results point the neutralization process and the ionizing electron production rate by the cathode as critical issues. Both maximize the outgoing ion current of this throtteable ion thrusters. Finally, the estimated levels of thrust are found comparable with those of similar devices. Session: C Paper: 27 Time: 03:00 PM Student Name: Luciano Fanton Institution: PoliMI, Milano Country: Italy Paper Title: Radiation Effects on Solid Fuel Regression in a Hybrid Micro-Burner Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Fanton_PoliMI.pdf ABSTRACT The main hindrance that prevents hybrid rocket propulsion success is the low regression rate of the solid fuel, that ultimately leads to low engine thrust. In order to avoid this, innovative solid fuel formulations have been developed, loading HTPB-based solid fuels with energetic additives: in this work, ballistic characterization of a variety of solid fuels is performed. The effects of radiative heat transfer on the regression rate is evaluated based on the analytical models available in the literature. Under the investigated conditions, analysis of experimental data showed a great influence of the radiative heat due to burnt gases and soot on the regression rate of unloaded and loaded formulations. Session: C Paper: 28 Time: 04:00 PM Student Name: Ruslan Farshatov Institution: USATU, Ufa Country: Russian Federation Paper Title: Modelling of operation processes in gas turbine and rocket engines Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Farshatov_Ufa.pdf ABSTRACT For design and operation of various types of engines various modeling systems are used. Modern modeling systems usually focus on a certain class of objects and tasks to be solved. Thus, the modeling system DVIGw is designed for thermal gas-dynamic modeling of operation processes in GTE with various schemes in the zero-dimensional quasi-stationary approximation. Engines of other types, for example, SFRE even at the early design stage require the use of non-stationary models. In addition, operation processes in such engines differ from the processes in GTE. Nevertheless, as is shown below, there is a possibility to unify models of a number of elements that allows using them for modeling both GTE and SFRE. Addition of new elements to the library allows expanding modeling system capabilities for analysis in the same environment of both GTE and SFRE, and in the prospect also rocket engines, internal combustion engine and various combined engines. This extends the capability of the designer and shows the need for and the possibility of continuous development of systems simulation in the design process of new aircraft engines (AE). Session: C Paper: 29 Time: 04:30 PM Student Name: Dominik Puckert Institution: Uni Stuttgart, Stuttgart Country: Germany Paper Title: Development of a Cavity Calorimeter for the Inductively Heated Plasma Generator IPG6-S Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Puckert_Stuttgart.pdf ABSTRACT A cavity calorimeter has been designed, built and set in operation to characterize the inductively heated plasma generator IPG6-S at the Institute of Space Systems (IRS) at the University of Stuttgart. IPG6-S is the latest small-scale inductive plasma generator of IRS that enables student experiments on high-enthalpy plasma flows. These experiments can be simulations of plasma during planetary re-entry of a spaceship for investigations on thermal protection systems or fundamental research on catalysis or radiation of plasma states. The cavity calorimeter was built to determine the mean specific enthalpy and efficiency of the plasma beam and therefore achieve a first calorimetric and performance characterization. For air as working gas, the mean specific enthalpy of the plasma beam could experimentally be determined to range from 1 to 13 MJ/kg, depending on the air mass flow rate and the anode current. Since the mean specific enthalpy of the plasma flow characterizes the plasma beam’s degree of ionization and dissociation in a thermodynamic model, important conclusions can be drawn in future experiments regarding the thermal stress on a spaceship during re-entry. Further, the performance of IPG6-S has been experimentally quantified by determining a thermal efficiency that achieved values of up to 30%. At the most efficient working point, the total system efficiency achieved 21%. With these results, not only a successful first characterization of IPG6-S has been accomplished, but also a basis for concepts to possibly raise the mean specific enthalpy and efficiencies is being provided. Session: C Paper: 30 Time: 05:00 PM Student Name: Arsen Abdulin Institution: USATU, Ufa Country: Russian Federation Paper Title: Numerical simulation of processes in gas turbine combustors Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Abdulin_Ufa.pdf ABSTRACT The verification problems of fluid flow and burning in the elements of the gas turbine combustors is solved. The simulation of fluid flow in a cylindrical tube using both different turbulence models and different grid in the boundary layer was carried out; the simulation results are compared with empirical dependences. In the problem of mixing jets from main holes of the flame tube is chosen the turbulence model and its adjustment is made. The numerical analysis of air flow in a plane diffuser was carried out; the results of numerical analysis are compared with the field experiment. In the problem of the combustion the turbulent eddy dissipation model is chosen, the coefficients for one-step brutto-reaction are selected, the simulation results are compared with experimental data. In combustion problems the radiative heat transfer is necessary to taking into account. For the problems of combustion and flow selection and justification a model of radiative heat transfer is made. On the basis of the solution of verification tasks the effect of defects in the flame tube and layer-by-layer cooling sections on the temperature field at the exit of the combustor was modeled. Session: C Paper: 31 Time: 05:30 PM Student Name: José Amer Llobera Institution: ETSIA, Madrid Country: Spain Paper Title: Adaptation of the ESPSS/EcosimPro platform for the design and analysis of liquid propellant rocket engines Paper link: http://www.pegasus-europe.org/AIAA_Pegasus/Papers/Amer_Llobera_ETSIA.pdf ABSTRACT The preliminary design of rocket engines has been historically a semi-manual process, where the specialists work out a start point for the next design steps. Thanks to the capabilities of the EcosimPro language, such as non causal programming, a natural pre-design model has been physically discomposed in three modules: propulsion performance, sizing and mass, and mission requirements. Most of the new stationary capabilities are based on the ESPSS libraries, which are able to simulate in great detail transient phenomena of fluid systems (e.g. tanks, turbomachinery, nozzles and combustion chambers). Once the base of the three pre-design modules is detailed, an effort has been made to determine accurately the mission requirements. For example, in a geostationary transfer orbit insertion manoeuvre, the maximum change of speed is obtained considering a finite combustion, instead of the ideal Hohmann transfer orbit. Finally, the model validation and two application examples are presented: the first one compares the model results with the real performance of the Aestus pressurized rocket engine. In the second one, the relation between the initial total vehicle mass and the design parameters (combustion pressure, mixture ratio and nozzle area ratio) is obtained, looking for an optimized pre-design. And the last one, take advantage of the ESPSS transient capabilities simulating a transient engine run (startup, manoeuvre and shutdown), which is used as simplified analysis to verify the optimum pre-design.
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