Stability, Flying Qualities and Parameter Estimation of a Twin-Engine CS23/FAR23 Certified Light Aircraft

This paper presents some results of the flight test campaign conducted on the Tecnam P2006T aircraft, on the occasion of its certification process. This twin-engine propeller airplane is certified in the category CS23/FAR23. Many preliminary flight tests on a prototype of this light aircraft were aimed at optimizing performances and flight qualities. These experiences led to the application of two winglets to the original wing. The final configuration was extensively tested for the purpose of CS23 certification achievement. At the same time the airplane model, through a dedicated set of flight maneuvers, has been characterized by means of parameter estimation studies. The longitudinal and lateral-directional response mode were assessed and quantified. All the aircraft stability derivatives have been estimated from the acquired flight data using the well-known Maximum Likelihood Method (MLM). Some estimated stability derivatives have been also compared with the corresponding values extracted from leveled flight tests and from wind-tunnel tests performed on a scaled model of the aircraft

Development of a Java-Based Framework for Aircraft Preliminary Design and Optimization

The paper deals with the description of a software tool to be used for aircraft preliminary design and optimization. The software tool, called ADOpT (Aircraft Design and Optimization Tool) has been developed in order to have a fast, reliable and user friendly framework to be used in preliminary/conceptual design phase. The software platform is made to perform fast multi-disciplinary analysis of an established aircraft configuration and search for an optimized configuration in a domain whose boundaries are defined by the user. The software has been conceived to be used in an industrial environment across conceptual and preliminary design phases. The software is still in development at the Department of Industrial Engineering of University of Naples

MDO applications to conventional and novel turboprop aircraft within agile European project

In this paper, multidisciplinary design optimization within the AGILE European project is applied to two turboprop aircraft. The first one is a conventional configuration characterized by wing mounted engines, while the second one is an innovative configuration with rear engines installation on the horizontal tail tip with an innovative power plant architecture. Both configurations are suited for 90 passengers, a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The methodologies used to analyze both configurations include aerodynamic performance in clean, landing and takeoff configurations, mission performance, weight and balance, stability and control, emissions, in terms of Global Warming Potential parameter, and Direct Operating Cost estimation. The latest two will be considered as objective functions for the optimization loop. Aim of this paper is to compare both configurations highlighting benefits and limits. Particular attention has been posed on the innovative approach used to analyze the use cases. The whole design process is made up ofdifferent tools belonging to a specific partner. Each partner is specialized in a specific discipline. The design process has been setup to be completely automated so that, partners, distributed worldwide are able to communicate and exchange results through remote connection. In this way each discipline has been assigned to the suited specialist

Boundary states for moving D-branes

We determine the boundary state for both the NS-NS and R-R sectors of superstring theory. We show how they are modified under a boost. The boosted boundary state is then used for computing the interaction of two D-branes moving with constant velocity reproducing with a completely different method a recent calculation by Bachas.Comment: 10 pages, LaTeX, no figures; Eqs. (47) and (48) correcte

Instanton effects in N=1 brane models and the Kahler metric of twisted matter

We consider locally consistent systems of magnetized D9 branes on an orbifolded six-torus which support N=1 gauge theories. In such realizations, the matter multiplets arise from "twisted" strings connecting different stacks of branes. The introduction of Euclidean 5 branes (E5) wrapped on the six-dimensional compact space leads to instanton effects. For instance, if the system is engineered so as to yield SQCD, a single E5 brane may account for the ADS/TVY superpotential. We discuss the subtle interplay that exists between the annuli diagrams with an E5 boundary and the holomorphicity properties of the effective low-energy action of the N=1 theory. The consistency of this picture allows to obtain information on the Kahler metric of the chiral matter multiplets arising from twisted strings.Comment: 33 pages, 4 figures. V2: improved discussion, clarifyng comments and references added. Version to be published in JHE

The completion and local cohomology theorems for complex cobordism for all compact Lie groups

We generalize the completion theorem for equivariant MU-module spectra for finite groups or finite extensions of a torus to compact Lie groups using the splitting of global functors proved by Schwede. This proves a conjecture of Greenlees and May.Comment: 12 page

Game theory and evolutionary algorithms applied to MDO in the AGILE European project

In this paper, an optimization technique in aircraft design field, based on game theory and evolutionary algorithms to define the key variables for Multi-Disciplinary aircraft Optimization (MDO) into AGILE (Aircraft 3rd Generation MDO for Innovative Collaboration of Heterogeneous Teams of Experts) European project, is presented. This work represents one of the contributions given by UniNa (University of Naples “Federico II”) research group within the AGILE project, which is coordinated by the DLR and funded by EU through the project HORIZON 2020 that aims to create an evolution of MDO, promoting a novel approach based on collaborative remote design and knowledge dissemination among various teams of experts. Since the aircraft design field is very complex in terms of number of involved variables and the dimension of the space of variation, it is not feasible to perform an optimization process on all the design parameters; this leads to the need to reduce the number of the parameters to the most significant ones. A multi-objective optimization approach allows many different variables, which could be a constraint or an objective function for the specific investigation; thus, setting the constraints and objectives to reach, it is possible to perform an optimization process and control which parameters significantly affect the final result. Within AGILE project, UniNa research group aims to perform wing optimization processes in a preliminary design stage, coupling Nash game theory (N) with typical genetic evolutionary algorithm (GA), reducing computational time and allowing a more realistic association among objective functions and variables, to identify the main ones that significantly affect final result and that consequently must be considered by the partners of the AGILE consortium to perform MDO in the final part of project, applying the proposed optimization technique to novel aircraft configuration

Anomalies and inflow on D-branes and O-planes

We derive the general form of the anomaly for chiral spinors and self-dual antisymmetric tensors living on D-brane and O-plane interesections, using both path-integral and index theorem methods. We then show that the anomalous couplings to RR forms of D-branes and O-planes in a general background are precisely those required to cancel these anomalies through the inflow mechanism. This allows, for instance, for local anomaly cancellation in generic orientifold models, the relevant Green-Schwarz term being given by the sum of the anomalous couplings of all the D-branes and O-planes in the model.Comment: 24 pages, LaTex file, no figure

Scale independent spin effects in D-brane dynamics

We study spin interactions between two moving D-branes using the Green-Schwarz formalism of boundary states. We focus our attention on the leading terms for small velocities v, of the form v^{4-n}/r^{7-p+n} (v^{2-n}/r^{3-p+n}) for p-p (p-p+4) systems, with 16 (8) supercharges. In analogy with standard G-S computations of massless four-point one-loop amplitudes in Type I theory, the above terms are governed purely by zero modes, massive states contributions cancelling as expected by the residual supersymmetry. This implies the scale invariance of these leading spin-effects, supporting the relevant matrix model descriptions of supergravity interactions; in this context, we also discuss similar results for more general brane configurations. We then give a field theory interpretation of our results, that allows in particular to deduce the gyromagnetic ratio g=1 and the presence of a quadrupole moment for D0-branes.Comment: 31 pages, 3 figures, RevTex; final version to appear on Nuclear Physics