Showing papers in "Aerospace Science and Technology in 2010"

TL;DR: An improved ABC optimization algorithm based on chaos theory for solving the UCAV path planning in various combat field environments is proposed, and the implementation procedure of the proposed chaotic ABC approach is described in detail.

TL;DR: In this article, the authors compare the performance of three recursive parameter estimation algorithms for aerodynamic parameter estimation of two aircraft from real flight data, including Extended Kalman Filter (EKF), unscented Kalman filter (UKF), and augmented version of the UKF.

TL;DR: In this article, the effects of skin flexibility of the tested wings on their aerodynamic performances for both soaring and flapping flights were evaluated. And the results revealed that flapping motion would bring significant aerodynamic benefits when the flapping flight is in unsteady state regime with advance ratio (i.e., the ratio of forward flight speed to wingtip velocity) being smaller than 1.0.

TL;DR: In this paper, arc-jet experiments on different ultra high temperature ceramics (UHTC) models in high enthalpy hypersonic non-equilibrium flow are considered.

TL;DR: Details of the PADGE code under development at the German Aerospace Center (DLR) that is aimed at large-scale applications in aerospace engineering are presented, including several advanced aspects like the solution of the Reynolds-averaged Navier–Stokes and k – ω turbulence model equations.

TL;DR: In this paper, a single-cylinder, naturally aspirated, air-cooled, direct-injected diesel engine was used to study the effects of oxygen enrichment of intake air on engine performance at simulated high altitude conditions.

TL;DR: In this paper, the microstructure, microhardness, and mechanical properties of the joint have been investigated using electron beam welding technique, and the results show that EBW can be used the joining of dissimilar TC11 alloy and Ti-22Al-25Nb alloy.

TL;DR: In this paper, the interference effects of side jets with supersonic cross flow for a lateral jet controlled missile are simulated numerically using a commercial CFD software and a very good agreement between computed and experimental surface pressure has been obtained.

TL;DR: In this paper, the evolutionary genetic algorithm is applied to find the optimum design based on each of the surrogates for these two objectives, which produced 92% and 13% reduction in drag and wall temperature responses, respectively.

TL;DR: In this article, a methodology for the design optimization of a skin-stringer panel of an aircraft wing-box is presented, where the ability to resist the compressive load is assessed through a stability study to compute the critical buckling load of the stiffened panel while the ability of resist the tensile load was assessed through damage tolerance analysis of the lower wing panels.

TL;DR: In this paper, a nonlinear suboptimal reentry guidance scheme for a reusable launch vehicle (RLV) is presented using the recently developed model predictive static programming (MPSP) technique.

TL;DR: In this article, the design of an active extrados structure for an experimental morphing laminar wing, which has been tested in a subsonic wind tunnel, is discussed.

TL;DR: A methodology based on high-order singular value decomposition is presented to compress multidimensional aerodynamic databases, and it is concluded that a large compression factor is generally obtained.

TL;DR: In this paper, a non-standard anti-windup control strategy is developed in order to improve the on-ground control system of a civilian aircraft using a linear fractional representation (LFR) of the aircraft in combination with an original approximation of the nonlinear ground forces by saturation-type nonlinearities.

TL;DR: In this article, a non-linear multi-objective optimal control problem is formally identified and detailed, and a strategy for designing noise abatement procedures, aimed at reducing the exposure to noise of the population living around the airports is presented.

TL;DR: In this paper, a quaternion-based spacecraft model was proposed to describe the nadir pointing spacecraft with momentum wheel under gravity gradient torque disturbance, and a linearized state space model was derived for the spacecraft system.

TL;DR: In this article, the authors focus on understanding the thermal environment and the response of the multifunctional structure to that environment and show that the concept can be implemented in many orbits without any particular thermal control and that many more orbits could be used with thermal control of a suitable authority.

TL;DR: In this article, the attitude angular velocity induced thrust vector constraint is converted into thrust vector maneuverability constraint, which is nonconvex and cannot be implemented in the optimization framework directly.

TL;DR: In this paper, a non-recursive batch filter based on the unscented transformation is presented and utilized for satellite orbit determination, which yields more robust and stable convergence than the existing batch least squares filter.

TL;DR: In this paper, an extensive parametric study was conducted to examine the effect of continuous blowing from high aspect ratio jets on the tip vortex in the near wake, and it was found that the high aspect-ratio jet produces a pair of counter-rotating vortices of unequal strength; their interaction with the tail tip vortex leads to single or multiple-vortex wakes.

TL;DR: In this paper, the concept of web-Tensairity was further developed into curved girders to build wings with dihedral, sweep and twist, and a kite prototype has been built.

TL;DR: In this article, an experimental study of the response to downstream pressure perturbations of transonic shocks in a parallel walled duct has been conducted, where the interaction structure between the oscillating shock and the tunnel wall turbulent boundary layer varies during oscillations, especially at M ∞ = 1.4.

TL;DR: The EOS, in this paper, can track images and take 3-D measurement of a target as well as acquire high quality images and the used optimal method to reduce measurement error is Sequential Quadratic Programming (SQP).

TL;DR: In this article, a loosely coupled CFD/CSD method was used for aeroelastic analysis of flexible high-aspect-ratio flexible UAVs, where an unsteady Euler solver and a nonlinear CSD solver were combined by a fully three-dimensional integral constant volume tetrahedron (CVT) interfacing technique.

TL;DR: In this paper, the authors investigated nonlinear acoustic damping induced by a half-wave resonator by adopting nonlinear analysis and found that the damping effect induced by fine tuning of the resonator is degraded rather by nonlinear acoustics.

TL;DR: A binary decentralized distributed decision fusion in which a system of multiple independent sensors monitors a common volume and provides relevant binary decisions about the state of the environment to a data fusion center.

TL;DR: A method is presented to construct a model of a human pilot which takes visual cues and generates longitudinal control actions during the visual approach to landing, based on numerical data from real or simulated landings by human pilots.

TL;DR: In this article, the Detached Eddy Simulation (DES) approach was used for the computation of flows around uninhabited combat air vehicles, where a realistic aircraft geometry is used in contrast to previous studies where idealised, isolated cavities are used as model problems.

TL;DR: In this paper, the authors proposed a simple approximate technique to estimate the mode I stress intensity factor of interacting collinear cracks under external load in an infinite body under far field tension considering interactions between all cracks.

TL;DR: In this paper, an adaptive controller based on feedback linearization approach and using Lyapunov design method is proposed to manage the system performance during various maneuvers, and an optimal controller is designed to compare its performance with the designed adaptive controller.