This paper describes an experimental study of the interaction between a hypersonic flow and a transverse jet which issues radially from a slender conical model. Measurements in the region far upstream of the jet show qualitative agreement with free interaction analyses, while downstream a film cooling effect appears to reduce the heat transfer rate substantially. The effect of changes in Reynolds number, jet pressure ratio and mass flux is examined and compared with similar phenomena caused by fixed disturbances such as compression corners. The shape of the interaction shock wave is found to agree with the predictions of the second-order blast wave theory. Finally a correlation is found between the boundary layer separation length and a local mass flux parameter.

Linear elastic buckling strength assessments are presented for a range of thin plate arrays with optimal strength to weight ratio configurations subject to a range of arbitrary in-plane stress states. The outcomes of the assessment are presented as design curves demonstrating relative buckling strength increases with respect to the classical square plate datum of equal mass.

A stiffness matrix method is adopted for the initial buckling strength predictions. The method is based on exact flat plate theory and assumes that the plate is continuous over supports, whereby deformations in one cell of the plate array influence the deformations in adjacent cells. The supporting webs of each cell are approximated in this study by simple rigid supports that enforce nodal lines or lines of zero out-of-plane displacement in the buckled panel, i.e. the bending and torsional stiffness provided by the supporting webs of the real structure are ignored. Selected results are validated by FEM prediction.

The Nature of the flow in the exhaust pipe of a turbo-charged two- or four-stroke cycle engine is in general so complex that practical tests on running machinery are necessary to compare the merits of one exhaust system with another. The analysis of the results of these tests is rendered somewhat difficult by the lack of reliable methods for measuring accurately the transient temperatures in the exhaust pipe. Indicator diagrams have therefore to be used in conjunction with empirical methods for computing the exhaust energy, these methods being associated with the measured exhaust pyrometer temperature. In calculating the theoretical possibilities of different exhaust pipe configurations for four-stroke cycle engines Jenny has suggested that the total energy was the sum of the internal and kinetic energies of the gas entering the pipe. In the present treatment it is suggested that a better criterion is the enthalpy available if the gas expands isentropically from stagnation conditions to atmospheric pressure, the justification being that this would be the energy utilised in the turbine.

Flying, in common with all means of transport, is affected by adverse weather conditions, but the necessity of aeroplanes to maintain flying speed introduces a major difficulty of its own. The older forms of transport are able, in the last resort, to evade their difficulties by coming to a dead stop. An aeroplane must, literally, fly in the face of its difficulties. It must fly blind in clouds and perhaps land in fog. Over and above this, flight under certain meteorological conditions introduces a danger unique to aircraft. Ice may deposit at all leading edges and grow to windward, at critical regions of the relative airflow, in shapes which increase drag and seriously decrease lift. The accumulated ice adds to the weight. Unsymmetrical ice deposits on the airscrew blades cause dangerous engine vibrations which can only be kept in check, if at all, by throttling back at the expense of thrust. Venturis and pressure head orifices become blocked with ice, rendering the instruments they serve useless. External controls may become jammed. In short, many adverse factors to prevent flight may be brought into play simultaneously by the mere fact that particular meteorological conditions have been encountered.

Aircraft upset and Loss of Control (LOC) is a leading cause of accidents in commercial and general aviation aircraft operations. A number of measures have been taken in the commercial segment to improve training and awareness of this problem and several organisations offer in-flight training to enhance awareness. In relative terms, in both commercial and general aviation sectors, the use of Full Flight Simulators (FFS) and Flight Training Devices (FTD) for this purpose is minimal. A key reason for this is the limited capability and coverage of flight models used in these devices. This paper provides examples of the limitations in civilian simulators in contrast to military efforts that have been using full envelope modelling for decades to enhance pilot training. The paper also presents techniques used in full-envelope modelling, their validity, and a regulatory vehicle that is in-line with current international guidelines for application to civilian trainer development.

Probably few readers realize the advance which has been made towards a practical solution of the problem of aviation within the last eight years. It is greater than all that was accomplished during the preceding two centuries. Not only has the subject been rescued from the contempt brought upon it by past failures and eccentric proposals, but very able men—Langley, Maxim, Pilcher, Hargrave, and Lilienthal—have shown by their experiments and writings that man may fairly hope eventually to fly through the air.

Hundreds of failures during the last 300 or 400 years have well shown what arrangements will not answer, but the labours of these latter experimenters now enable us to forecast that success is most probably to be won with aerocurves, driven by screws or flapping propellers, actuated by a steam or a petroleum engine.

What is the best course to be now followed to make still further advance? Most of the above experimenters seem to have proceeded upon the assumption that it is practicable to evolve a complete flying machine at one operation, and to apply propellers and motors from the first, before we are quite certain as to the stability in a wind.

Modern gas turbine combustor design is a complex task which includes both experimental and empirical knowledge. Numerous parameters have to be considered for combustor designs which include combustor size, combustion efficiency, emissions and so on. Several empirical correlations and experienced approaches have been developed and summarised in literature for designing conventional combustors. A large number of advanced technologies have been successfully employed to reduce emissions significantly in the last few decades. There is no literature in the public domain for providing detailed design methodologies of triple annular combustors.

The objective of this study is to provide a detailed method designing a triple annular dry low emission industrial combustor and evaluate its performance, based on the operating conditions of an industrial engine. The design methodology employs semi-empirical and empirical models for designing different components of gas turbine combustors. Meanwhile, advanced DLE methods such as lean fuel combustion, premixed methods, staged combustion, triple annular, multi-passage diffusers, machined cooling rings, DACRS and heat shields are employed to cut down emissions. The design process is shown step by step for design and performance evaluation of the combustor.

The performance of this combustor is predicted, it shows that NOx emissions could be reduced by 60%-90% as compared with conventional single annular combustors.

In this second Aeronautical Journal paper providing a technical appraisal of the Wright brothers' achievements, the authors use modelling and simulation and associated flight dynamics analysis to present the development of the first practical aeroplane. The aircraft in question, the Wright Flyer III, was deemed fit for service by the Wrights in October 1905, and had evolved significantly from the first powered aircraft of 17 December 1903. The appraisal tries to shed light on many of the flight handling problems that the Wright brothers faced during this, their third phase of aeronautical endeavour, in 1904 and 1905. They retained their unstable configuration born in the 1901 and 1902 gliders, gradually refining the performance and handling until they considered the aircraft was ready for market. Their process of refinement has been reconstructed in simulation within the Liverpool Wright project, highlighting the many important developments during a period when Wilbur and Orville's own documentation was limited. Apart from their engineering excellence, the Wright brothers are to be acknowledged for their perseverance and resolve in overcoming setbacks, for their ability to innovate and to recover and learn from their mistakes. In many ways the Wright brothers represent a model for the modern aeronautical engineer, and it is hoped that their legacy will be better preserved through the documentation of this project.

Although test rig data exists for ¼ circle turning vanes, the actual performance of these vanes once installed in a wind tunnel, and the extent to which test rig results are replicated, is rarely known. This paper compares pressure loss coefficient and velocity profile data from a vane test module with measurements taken in the low speed wind tunnel described in Ref. 1.

This work investigates the role of flexibility and resonant excitation on the deformation mechanism and aerodynamic performance of flapping wings. A hummingbird-inspired wing (HIW) is considered and designed to have a bone-like stiffener made of carbon fibre/epoxy (CF/E) composite attached to a membrane made of carbon nanotubes/polypropylene (CNTs/PP) nanocomposite representing the flexible part of the natural wing. The designed HIW model is analysed through fluid-structure interaction simulations performed at frequencies near and at resonant frequency. It is found that HIW generates desired bending and twisting deformations that are coupled. These deformation mechanisms are studied in detail with the help of time-varying deflections and bending-twisting angles. Further, the simultaneous effect of these parameters on the aerodynamic performance of the wing is also investigated. It is observed that the coupled nature of bending and twisting deformations is critical in enhancing the aerodynamic performance of flapping wings. In addition to that, the resonance generates higher amplitude of desired structural deformations that further enhances thrust as well as lift generation capability of the wing. The underlying mechanism for this is also explained by studying the flow around the deflected surface of the wing. Compared to off-resonant frequencies, vorticity and pressures are substantially higher for the wing at resonance. A physical model of HIW is realised using CNTs/PP and CF/E composites to perform experimental wing motion analysis and to validate the computational results. In conclusion, the present study provides a basis to design efficient biomimetic flapping wings for micro aerial vehicles (MAVs) by exploring flexibility and resonant excitation.

Calculations of the aerodynamic loads on wings in atmospheric gusts are an essential part of aircraft design for three main reasons. Firstly, an estimate of the gust loads which the aircraft must withstand is an important element of the structural design calculations in terms of ensuring both static load bearing capability and an adequate fatigue life. Secondly, the calculated gust loads provide the input to a suitable mathematical model of the aircraft structure in order to arrive at an assessment of aircraft accelerations and ride behaviour in expected levels of atmospheric turbulence. This is particularly significant for high speed military aircraft operating at low altitudes. Thirdly, aerodynamic loads due to gusts can be viewed as perturbing influences to aircraft stability so that the performance of an active control, gust alleviation or ride control system has to be considered with a detailed knowledge of the time variance of aerodynamic gust loads in mind.

Any review of the development of maritime satellite communications is essentially the history of Inmarsat and its predecessor system, Marisat. With perhaps two qualifications, one might extend the definition to mobile satellite communications generally. In the land mobile satellite communications domain two companies, Geostar and Qualcomm, have also made their mark. Geostar was recently declared bankrupt but Qualcomm continues to go from strength to strength.

We are frequently asked ‘what is Inmarsat?'. The term Inmarsat is generally used, and used herein, to mean the permanent staff (the Directorate), Land Earth Station (LES) operators, manufacturers and value-added service providers who offer mobile satellite communications products or services via the satellites and other infrastructure which makes up the Inmarsat system. It is, essentially, a partnership but within it there is also internal competition. LES operators compete in the provision of telecommunications services (quality is consistently high, but they each decide what services to offer and at what tariffs). Manufacturers compete to secure market dominance and profitabilty for their products. Not all will be equally successful. More than anything, Inmarsat is a global partnership dedicated to meeting mankind's need to communicate while on the move. It aims to do so cost-effectively and using satellites.

The A. & A.E.E. has been associated with rotorcraft in this country almost from their earliest days. For example, the records show that a C30A Autogiro was evaluated at Martlesham Heath in 1935. After the outbreak of war responsibility for development work in the rotary wing field was assumed by the Airborne Forces Establishment (later the Airborne Forces Experimental Establishment) and the accounts of such developments as the Rotachute and the airborne jeep have since become well known. In 1945 the A.F.E.E. was declared to be the official testing establishment for prototype helicopters and this responsibility has remained until the present time. The A.F.E.E. was merged in 1951 with the A. & A.E.E., becoming the Airborne and Helicopter Division of the latter Establishment.

With the introduction of each new generation of combat aircraft it has become popular to assume that they will be operated in a more conservative manner than previously and that less attention, therefore, need be paid to their spinning characteristics. Current experience, however, shows that inadvertent spins will continue to occur, and must be allowed for, if these aircraft are to be operated effectively and to the limit of their capability.

In this connection the Hunter provides an interesting case history, since it has been put to widescale use in a variety of roles and its erect and inverted spinning characteristics have been thoroughly investigated. These characteristics will be described both for their own sake and because of the applicability which they have to current high performance aircraft.

Free-form deformation (FFD) is a method first introduced within the graphics industry to enable flexible deformation of geometric models. FFD uses an R3 to R3 mapping of a deformable space to the global Cartesian space to produce the geometry deformation. This method has been extensively used within the design optimisation field as a shape parameterisation technique. Typically it has been used to parameterise analysis meshes, where new design geometries are produced by deforming the original mesh. This method allows a concise set of design variables to be used while maintaining a flexible shape representation. However, if a computer aided design (CAD) model of the resulting geometry is required, reverse engineering techniques would need to be utilised to recreate the model from the deformed mesh. This paper extends the use of FFD within an optimisation routine by using FFD to directly parameterise a CAD geometry. Two methods of linking the FFD methods with the CATIA V5 CAD package are presented. Each CAD integration technique is then critiqued with respect to shape optimisation. Finally the set-up and initialisation of a case study is illustrated. The case study chosen is the aerodynamic optimisation of the wing-fuselage junction of a typical passenger aircraft.

The integral equations for the pressure distribution on an oscillating thin wing having a prescribed velocity distribution in a supersonic flow are developed.

An important growth of air traffic is recorded, as compared with other forms of traffic. Fig. 1 is an example of the domestic-intercity passenger travel market in the USA and is characteristic; showing (millions of passenger miles)

stagnation for waterways;
stagnation for autocars—buses;
decreasing for railroads;
expansion for airlines: annual growth rate of 10% over the past fifteen years, and acceleration since 1962: mean annual growth rate 18%.
It is also important to mention the expansion in freight, which is about 20% a year, i.e. doubled every four years.

We report on the flight test results of an Airbus 320 during novel advanced required navigation performance (RNP) procedures which contain a fixed radius turn that delivers the aircraft onto a short instrument landing system (ILS) precision final. Moreover, the advanced RNP part contains altitude constraints and/or a coded vertical path angle. The approaches were flown automatically with guidance and autothrust as computed by the flight management system. We investigated the use of the fixed radius in conjunction with vertical path options onto (a) the performance of the speed profile for arrival time optimisation, (b) the vertical path during the RNP part of the procedure and (c) the performance of the autoland capability after a curved transition onto an ILS.

For the trials, we designed five instrument approaches to a runway equipped with ILS. A RF curve terminates at the ILS intercept point at heights of 550, 750, 1000, 1500 and 2000 ft above aerodrome level and each approach had four different initial approach fixes which corresponded to a track angle change of 30°, 60°, 90° and 180° during the constant radius turn-to-final. We constructed the procedure such that the altitude constraints at initial, intermediate and final approach fix describe a continuous vertical path with minus 2° inclination, transitioning to the –3° glide path of the ILS and intercepting the glide path from below. In all cases, the land mode of the flight guidance computer became active between 316 and 381ft radar altitude. The vertical path following error depended on the coding of the procedure in the database. With coded vertical path angle and altitude constraints, the vertical path following error was never greater than +57 m (above desired flight path) during the RNP part when flown by the automatic flight guidance system without any pilot intervention.

Classic flight control systems are still widely used in the industry because of acquired experience and good understanding of their structure. Nevertheless, with more stringent constraints, it becomes difficult to easily fulfil all the criteria with these classic control laws. On the other hand, modern methods can handle many constraints but fail to produce low order controllers. The following methodology proposed in this paper addresses both classic and modern flight control issues, to offer a solution that leverages the strengths of both approaches. First, an H∞ synthesis is performed in order to get controllers which satisfy handling qualities and are robust with respect to mass and centre of gravity variations. These controllers are then reduced and structured by using robust modal control techniques. In conclusion, a self-scheduling technique is described that will schedule these controllers over the entire flight envelope.