Icing in conditions where clouds contain both liquid and solid phase particles has attracted considerable interest in recent years due to numerous in-flight incidents including engine rollbacks in the vicinity of deep convective clouds in tropical regions. These incidents have prompted certification authorities to investigate and extend the icing conditions to include solid and mixed-phase clouds for airworthiness certification. These efforts have resulted in the amendments issued by the Federal Aviation Administration (FAA) and European Aviation Safety Agency (EASA) to the certification specifications of large aircraft, FAR-25 and CS-25, respectively. Flight tests, laboratory tests and computer simulations are among the acceptable means to show compliance with these specifications. Considerable effort has been spent worldwide in order to develop icing simulation software for liquid phase clouds in the past four decades, but until recently, most of these software did not have the capability for solid- or mixed-phase clouds. One of the aims of the High Altitude Ice Crystals (HAIC) project funded by the European Commission within Framework Program 7 is to address this shortcoming. The present study combines the models related to solid- and mixed-phase icing that is developed within HAIC with an in-house numerical tool. The tool has four modules; a flow-field solution module that uses the Hess-Smith panel method, a module for computing droplet and ice crystal trajectories and collection efficiencies using the Lagrangian approach, a thermodynamic module, and an ice accretion module that utilises the Extended Messinger Model. The numerical tool is tested against experimental test cases including liquid and mixed-phase conditions for various aerofoil and axisymmetric intake geometries. The agreement of the obtained results with experimental data is encouraging.

Various liquid and gaseous alternative fuels have been proposed to replace the kerosene as aircraft fuel. Furthermore, new combustion technologies were developed to reduce the emissions of aero-engine. A staged fuel injection arrangement for a lean burn combustion system was applied to improve the operability of an aero-engine by achieving high flame stability at reduced combustion emissions. Originally, both circuits (pilot and main) are fuelled by kerosene; moreover, the pilot injector is operating at low power (engine idle and approach) and the pilot flame is anchored in an airflow recirculation zone. In the case of the performed research, the pilot injector was modified to allow the use of gaseous fuels. Thus, the burner model allows a flexible balancing of the mass flows for gaseous and liquid fuel. The present paper describes the investigation of ignitability for the proposed staged combustor model fuelled by gaseous and liquid fuels. A short overview on physical properties of used fuels is given. To investigate atomisation and ignition, different measurements systems were used. The effectiveness of two ignitor types (spark plug and laser ignitor) was analysed. The ignition performance of the combustor operating on various fuels was compared and discussed in detail.

The development of new technologies – such as rapid prototyping – and the use of materials with improved properties – such as highly resistant extruded polystyrene foam which can be easily and precisely shaped, while conserving its mechanical properties – allow researchers to improve design concepts. This article details the development of a new set of morphing wings for a 15-kg maximum take-off weight Unmanned Aerial Vehicle (UAV) from concept design, to flight tests, including modelling, design optimisation, construction and wind-tunnel tests. A set of comparator-equivalent conventional wings have been used throughout in order to be able to judge any benefits stemming from the adoption of morphing technology. This article shows that the morphing wings provide a controllable aircraft while reducing drag by a factor of 40% compared to the comparator wings with conventional ailerons in a deflected position.

This paper proposes an adaptive guidance law for attacking a ground target based on motion camouflage strategy. The coefficients of normal and bi-normal feedback guidance law are given according to the relative motion relationship under Frenet frame. Utilizing the coefficients, the motion camouflage proportional guidance law is derived. In order to improve the initial overload characteristic of the missile, an adaptive feedback coefficient is introduced. Then, the adaptive guidance law is applied to a longitudinal plane interception problem with impact-angle constraint. Finally, the validity of this guidance law for air-to-ground missiles is proved by simulations.

As propeller-driven aircraft are the best choice for short/middle-haul flights but their acoustic emissions may require improvements to comply with future noise certification standards, this work aims to numerically evaluate the acoustics of different modern propeller designs. Overall sound pressure level and noise spectra of various blade geometries and hub configurations are compared on a surface representing the exterior fuselage of a typical large turboprop aircraft. Interior cabin noise is also evaluated using the transfer function of a Fokker 50 aircraft. A blade design operating at lower RPM and with the span-wise loading moved inboard is shown to be significantly quieter without severe performance penalties. The employed Computational Fluid Dynamics (CFD) method is able to reproduce the tonal content of all blades and its dependence on hub and blade design features.

The following tables are compiled from tests carried out at East London College on various materials of aeroplane construction, kindly supplied by Messrs. W. N. Brunton and Son, T. W. K. Clarke and Co., F. Handley Page, and H. EoUet and Co. Figure 1 shows the method of fixing the steel tapes during test. Table I. gives the results of these tests.

The aerodynamic resistance of wires. The apparatus used in these experiments was described by the author in his f Report to the Laboratory Committee of the Aeronautical Society of Great Britain. When the experiments herein described were started in 1910 no information on the resistance of wires and ropes was available, but the following papers have since been published :— “ The Resistance of Wires and Ropes in a Current of Air,” by B. Melville Jones, B.A. ; “ Comparison of the Resistances of Stationary and Vibrating Wires,” by T. E. Stanton, D.Sc, M.I.C.E. (Report of the Advisory Committee for Aeronautics, 1910-11) ; and “ The Tests of Smooth Wires and Wire-ropes made at the Gottingen “ Modellversuchsanstalt “ (Ztsch. fur Flugtechnik und Motorluftschiffahrt, Oct. 29th, 1910). Owing to the absence of funds the experiments of the resistance of wires have not been carried to a conclusion. The following data and conclusions are derived from a series of preliminary or trial experiments. They are published herewith for the guidance of future experimenters.

If one reflects on the great army of scientific men who are at present studying the subject of the motion of planes, at an angle, in fluids, it is very remarkable that the work of Avanzini on this subject should have escaped notice. All that appears to be known about this diligent experimentalist is in reference to what is known as “ Avanzini's law,” in relation to the position of the centre of pressure on a moving plate. This law is quoted by Professor Bryan and M. Alexandre See (to quote two only of the most eminent writers on the subject), but they omit to say from whence they get the formula. M. Alexandre See, in a private letter, has kindly informed me that “ je crois qu'on a appele ‘ Loid ‘ Avanzini ‘ une loi qu'il n'a jamais formulee lui mime., mais qu'il a etudiee.” Whatever Avanzini may have said on the subject is probably to be found in the Memorie della Academia di Padova, but the volume containing his memoir does not appear to be in England; in any case 1 have not been able to find it.