This paper investigates the feasibility of improving the aircraft landing performance by design the damping orifice parameters of the landing gear using lattice Boltzmann method coupled with the response surface method. The LBM is utilised to simulate characteristics of the damping orifice after model validation. The numerical model of the landing gear using simulated damping force is validated by single landing gear drop test. Based on the numerical model and the response surface functions, the sensitivity analysis and the optimisation design are performed. The maximum error of mean velocity simulated using LBM with experimental data is 7.07% for sharp-edged orifices. Moreover, the numerical model predicts the landing responses adequately, the maximum error with drop test data is 2.51%. The max overloading of the aircraft decreases by 5.44% after optimisation, which proves that this method is feasible to design the damping orifice for good landing performance.

For the past half-century the tank has dominated the land battle by virtue of its armour.

During the last war, the discovery of the shaped high explosive charge (or hollow charge) was the first significant step towards its decline. This type of warhead could penetrate the thickest armour then in use, without the need for its carrier to have any significant velocity. No longer were projectiles of high kinetic energy, and therefore high velocity, required.

The Gliding and Soaring Flight movement is as old as History. The observation of bird flight must have shown the men of former centuries in the same way as our own generation, that apart from power flight with wing beats there must be another flight possibility, enabling the use of the energy in the movement of air masses for flight without the expenditure of other power. The experiments undertaken in these times on the solution of the flight problem have come down to us only through myths and sagas, and we cannot differentiate between truth and imagination in these stories.

Experimental research, which can certainly be considered as the foundation of modern physics, has also in the realm of aerodynamics laid the basis for modernaeronautics. In this gliding and soaring flight plays the rôle of full–scale experiments, not as an end in itself, but as a proving-ground and last station before the invention of power flight.

Let Г be a closed curve in the z-plane with p-axis of symmetry. The mapping function

maps in general the interior of the unit circle |ξ| < 1 on to the interior of Г such that ξ=0 is transformed into z=0.

Asymmetric vibration of multilayered conical shell with core layers of viscoelastic material are investigated in this paper. The analysis presented herein considers bending, extension in plane shear and transverse shear deformations in each of the layers, and also includes rotary, longitudinal translatory and transverse inertias. Appropriate trigonometric series are used as solution functions in the Galerkin method to reduce the governing equations to a set of matrix equations. The corresponding principle of linear viscoelasticity for harmonic motion is used for evaluating the damping effectiveness of shells with elastic and viscoelastic layers. A computer program has been developed for determining the resonance frequencies and associated system loss factors for various modes of families of asymmetric vibration of a general multilayered conical shell consisting of an arbitrary number of specially orthotropic material layers. Variation of resonance frequencies and the associated system loss factors with total thickness parameter and circumferential modal number for three, five and seven layered conical shells, with three sets of classical end conditions: simply supported at both ends, clamped-clamped and free-free, which can be of some use to designers, are been reported.

The aim is to explore the philosophy of air traffic management with different strategic visions of the future: to answer the key question: ‘Who is to prevent mid-air collisions and how are they to accomplish this?’ The best strategic vision may just be the one that has the best match with the consensus on the desired strategic direction. Nevertheless, it must satisfy the main safety, financial, human performance etc. constraints. To explore the question, a blend of concepts from a range of disciplines has been used. These include risk analysis, financial decision-making, ‘cognitive engineering’ research and simple cybernetics. ‘full delegation’ – with pilots being responsible for all the tasks related to separation assurance – appears to meet most of the constraints. Some important issues for safety analyses of full delegation are sketched. Research into the nature and rate of future conflicts in a full delegation environment, using models of error processes, is crucial.

Classification of the winged aircraft according to the character of wing (blade) motion in horizontal and vertical plane is presented. Design of a rotor, the blades of which are driven into rotation via flapping motion similar to the movement of an ornithopter's wing is proposed and the principle of operation is considered. Mathematical model of the aerodynamics of the autorotating rotor with flapping blades in hover is made on the base of the helicopter rotor blade-element theory. Geometric and kinematic parameters influence on the rotor lift and efficiency is analysed. It is shown that in hover the efficiency of an autorotating rotor with flapping blades is approximately equal to the one of a helicopter rotor.

An experimental study of double cone geometries in hypersonic flow (at M∞ of 8·2 and Red of 0·36 × 106) was performed to provide additional data to a computational simulation study. In this study, depending on how the flow was initialised, the numerical solution yielded a violent pulsation mode of instability or a steady flow. Finally, an analysis of the shock oscillation was made and discussed.

The results of an experimental evaluation of three assessment criteria for boundary layer two-dimensionality are presented. The criteria include the so-called ‘two pin test', the momentum balance principle and the cross-stream variation in local skin friction coefficient. Extensive spanwise measurements in the flows investigated highlight the relative merits and limitations of the criteria imposed.

The momentum balance method is found to be the most informative technique, with the proviso that the test data must be interpreted with some care if measurements are restricted along a single streamwise axis.

The two pin test is found to provide a worthwhile complimentary addition to momentum balance data, whereas the spanwise variation in local skin friction coefficient is less conclusive as regards flow two-dimensionality.

Excepting the case of adverse pressure gradient flows, the momentum balance equation is seen as a viable experimental means of estimating the local skin friction coefficient in boundary layers where measurement is problematical, as in the case of transitional boundary layers. In such cases, the two pin test could be used as the sole means of confirming the flow two-dimensionality.

A formation control and obstacle avoidance algorithm has been introduced in this paper for the V-shape formation flight of fixed-wing UAVs (Unmanned Aerial Vehicles) using the potential functions method. An innovative vector approach has been suggested to fix the conventional challenge in employing the artificial potential field (APF) approach (the creation of local minimums). A method called variable repulsive circles (VRC) has been then presented aimed at designing proper flight paths tailored with functional limitations of fixed-wing UAVs in facing obstacles. Finally, the efficiency of the designed algorithm has been examined and evaluated for different flight scenarios.

An implicit cell-vertex upwind method is presented for the solution of the two-dimensional Euler equations for supersonic flows. It is based on the two-point difference scheme introduced by S.F. Wornom, but contains many significant developments. Particular attention is given to the implementation of boundary conditions, to ensure that no “numerical” boundary conditions are required, and “image” cells are avoided, making the scheme ideal for use in conjunction with a multiblock approach. Examples are given for quasi-one-dimensional nozzle flows, and in two dimensions, oblique shock reflection, a shock interaction problem, and a supersonic intake problem. The accuracy and efficiency of the scheme is demonstrated, along with its ease of use.

It is shown that, for infinite sheared wings with symmetrical aerofoil sections, the value of the suction peak near the nose in incompressible flow depends primarily on the value of the lift coefficient and the nose radius and not on the angle of sweep.

When investigating the suitability of a basic wing section for an aircraft design with comparatively large aspect ratio, it is useful to know up to which lift coefficient one can expect the flow to be attached over the wing surface, and separation to occur at the trailing edge only. For aerofoils of small or moderate thickness-chord ratio, flow separation tends to occur first near the leading edge.

Prompted by claims made in the popular aviation literature, analysis is used in an attempt to estimate the turning performance of certain fighter aircraft flown during the Battle of Britain. In this it is necessary to provide values for such aerodynamic quantities as the drag coefficient at zero lift and these are estimated from published flight data.

For the computer simulation of bodies moving through real fluids input data about the aerodynamic and inertial forces and moments developed on them are required. It has long been known that under appropriate conditions the apparent masses of the body can play an important role in the determination of dynamic characteristics and this is certainly the case with parachute systems. In the past, because of inadequate experimental investigations, not all of the implications of apparent mass for this system have been fully appreciated. The current objective is therefore, in the light of experiments conducted on the measurement of apparent masses for some parachute canopies, to derive the relevant equations of motion for the parachute and store system and thus to determine the effects of various parameters on the dynamic characteristics of fully-deployed parachutes. In this system the store has been assumed to be rigidly connected to the canopy.

Route planning and airspace sectorisation are two central tasks in air traffic management. Traditionally, the routing and sectorisation problems were considered separately, with aircraft trajectories serving as input to the sectorisation problem and, reciprocally, sectors being part of the input to the path finding algorithms.

In this paper we propose a simultaneous design of routes and sectors for a transition airspace. We compare two approaches for this integrated design: one based on mixed integer programming, and one Voronoi-based model that separates potential “hotspots” of controller activity resulting from the terminal routes.

We apply our two approaches to the design of Stockholm Terminal Maneuvering Area.

The current drive towards reducing the environmental impact of aircraft necessitates the ability to evaluate techniques for promoting natural laminar flow in a large scale wind tunnel facility. A test was undertaken on the M2355 variable sweep model to obtain temperature sensitive paint (TSP) and hot-film data from which the transition locations at a range of sweep angles and flow conditions could be identified. The TSP technique has been shown to be a reliable method for determining transition on suitably treated wind tunnel models. Pressure data were also acquired and interpolated to provide the input to the laminar boundary layer code, BL2D, the output from which was used in the linear stability analysis code, CoDS, to calculate the N-factor for the ARA TWT (Transonic Wind Tunnel) facility. Two sets of N-factors were calculated, firstly using incompressible analysis with stationary crossflow and secondly using compressible analysis with travelling crossflow. In both analyses the Tollmien-Schlichting and crossflow cases were calculated together, rather than separating the cases before running the analysis. The resulting N-factors indicate a degree of scatter typical for experimental data. The N-factor based on incompressible theory for crossflow was found to be approximately 7 and for Tollmien-Schlichting (T-S), approximately 11. The results of the wind tunnel test and the analysis carried out are considered to be the first steps towards establishing a methodology for performance testing, in atmospheric tunnels such as the TWT, for aircraft designed to have significant regions of laminar flow. The project has also provided a body of experimental test data which will be valuable for future research into development and validation of laminar flow methods.

An experimental technique for assessing film cooling performance is proposed which can determine both film effectiveness and heat transfer coefficient distributions from a single infrared experiment. First, the film effectiveness is determined in the experiment’s steady-state phase on a series of film-cooled nozzle guide vane leading edge geometries made of a low thermal conductivity foam. Then, the effectiveness is used to calculate the distribution of the transient phase driving gas temperatures, which is applied to a finite element conduction model. Heat transfer coefficients are guessed and iteratively refined until the surface temperature histories predicted by the finite element model match those which were experimentally observed. Unlike conventional methods based on one-dimensional analytical heat transfer solutions, this approach does not require assumptions about the material thickness underlying the test surface or the uniformity with depth of its initial temperature distribution. This relieves certain experimental constraints and reduces uncertainty in results.

Looking back at the pioneering period of aviation one is struck by the almost complete lack of mechanical components in the early aeroplanes. Besides the single primitive engine there were no more than about a dozen hinges on control surfaces which, together with a few pulleys and levers, formed the entire mechanical system of the aircraft. As flying speeds increased, however, the need for mechanisms grew; retracting gear for the undercarriage became necessary, wings had to be fitted with flap gear, and engines and propellers received reduction gears and pitch varying mechanisms. The advent of the turbine opened further avenues for development; thus for flight at great heights cabin pressurisation became necessary, and supersonic flight demanded powered controls and flight stabilising mechanisms. Finally, a large family of VTOL aircraft, including the helicopter, came into existence.