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This paper aims to address shortcomings of current tiltrotor designs, such as the small aspect ratio of the wings, large download and the close proximity of the rotor tips. It also aims to avoid the complex transition of tiltrotors to normal airplane mode.

This design combines tiltrotor and tiltwing aircraft designs into a hybrid that is augmented by active flow control, using a gimbaled channel wing for attitude control in hover.

The proposed hybrid design is based on experimental results of components that were tested individually for potential use in hover and steep ascend from a stationary position.

This research was inspired by the extremely short take-off of the V-22, when its rotors were tilted forward. It combines several design approaches in a unique way to achieve extremely short take-off capabilities combined with high-speed and reduced maintenance costs.

2. The combination of an aerofoil including a leading edge and a trailing edge, and a vane member, said vane member comprising a pair of sections hinged together, means to pivotally secure one of said vane sections to said aerofoil so that said one section may fold upon the aerofoil, said wing having a channel extending there‐through, said channel including an opening close in advance of said vane whereby the vane when in open position increases the air flow through said channel, said channel having an exit in the rear of said vane, and means to swing said vane member outward from a position upon the aerofoil.

WE define as an open tube a thin‐walled structure, the cross‐section of which does not include any closed circuit. This property is common, for example, to the curved channel, the interspar wing cut‐out and the panel stiffened with Z‐sections, illustrated in FIG. 1 (a, b, c). But the interspar cut‐out with nose cell (FIG. 1d) is not an open tube in the present definition. All structures discussed in this paper are assumed to be cylindrical and to have a constant cross‐section. It is relatively simple to extend the results to conical taper and longitudinally varying thickness, but this would be beyond the scope and space of the present analysis (see, however, ref. 5).

An actuating unit for an aircraft remotely controlled element, comprising a motor including a drive shaft and a pair of field coils for rotating said shaft in opposite directions, an output shaft, complemental jaw clutch elements between said shafts, said clutch elements being adapted to be engaged to establish the driving relation between said shafts and disengaged to break the driving relation, a solenoid controlling said jaw elements, a solenoid switch for each of said field coils, a pair of spaced limit switches operatively connected to said solenoid and solenoid switches, a member movable between said limit switches to actuate one or the other, means drivably connected to said output shaft to cause movement of said member to engage one of said limit switches after a predetermined number of revolutions of said output shaft, contact means included in the circuit of said solenoid switches, and means to control said contact means from said jaw clutch elements whereby engagement of said clutch elements makes the contact and disengagement of the clutch elements breaks the contact.

The purpose of this paper is to investigate thermohydraulic characteristics of turbulent flow of water (4,000 = Re = 10,000) in a rectangular channel equipped with perforated chevron plat-fin (PCPF) with different vortex generators (VGs) shapes.

First, three general shapes of VGs including rectangular, triangular and half circle, are compared to each other. Then, the various shapes of rectangular VGs, (horizontal, vertical and square) and triangular VGs, (forward, backward and symmetric) are evaluated. To comprehensively evaluate the thermohydraulic performance of the PCPF with various VG shapes, the relationship between the Colburn factor and the friction factor (j/f) is presented, then a performance index (η) is applied using these factors.

Results show that the enhanced models of the PCPF, which are equipped with VGs, have higher values of j/f ratio and η as compared with the reference model (R). Further, the half-circle VG with the lowest pressure drop values (about 2.4% and 4.9%, averagely as compared with the S and ST vortex generators), shows the highest thermohydraulic performance among the proposed shapes. The maximum of performance index of 1.14 is found for the HC vortex generator at Re = 4,000. It is also found that the square and forward triangular VGs, have the best thermohydraulic performance among the rectangular and triangular VGs respectively and the highest performance index of 1.13 and 1.11 are reported for these VGs.

The thermohydraulic performance of the PCPF with different vortex generators VGs shapes have been investigated.

Designing new aircraft that are state-of-the-art and beyond always requires the development of new technologies. This paper aims to present lessons learned while designing, building and testing new UAVs in the configuration of the flying wing. The UAV contains a number of aerodynamic devices that are not obvious solutions and use the latest manufacturing technology achievements, such as 3D printing.

The design solutions were applied on an airworthy aircraft and checked during test flights. The process was first conducted on the smaller UAV, and based on the test outcomes, improvements were made and then applied on the larger version of the UAV, where they were verified.

A number of practical findings were identified. For example, the use of 3D printing technology for manufacturing integrated pressure ports, investigation of the adverse yaw effect on the flying wing configuration and the effectiveness of winglet rudders in producing yawing moment.

All designed devices were tested in practice on the flying aircraft. It allowed for improved aircraft performance and handling characteristics. Several of the technologies used improved the speed and quality of aerodynamic device design and manufacturing, which also influences the reliability of the aircraft.

The paper presents how 3D printing technology can be utilized for manufacturing of aerodynamic devices. Specially developed techniques for control surface design, which can affect adverse yaw problem and aircraft handling characteristics, were described.

This paper aims to present a computational aeroelastic capability based on a fluid–structure interaction (FSI) methodology and validate it using the NASA Common Research Model (CRM). Focus is placed on the effect of the wind tunnel model structural features on the static aeroelastic deformations.

The FSI methodology couples high-fidelity computational fluid dynamics to a simplified beam representation of the finite element model. Beam models of the detailed CRM wind tunnel model and a simplified CRM model are generated. The correlation between the numerical simulations and wind tunnel data for varying angles of attack is analysed and the influence of the model structure on the static aeroelastic deformation and aerodynamics is studied.

The FSI results follow closely the general trend of the experimental data, showing the importance of considering structural model deformations in the aerodynamic simulations. A thorough examination of the results reveals that it is not unequivocal that the fine details of the structural model are important in the aeroelastic predictions.

The influence of some changes in structural deformation on transonic wing aerodynamics appears to be complex and non-linear in nature and should be subject to further investigations.

It is shown that the use of a beam model in the FSI approach provides a reliable alternative to the more costly coupling with the full FE model. It also highlights the non-necessity to develop precise, detailed structural models for accurate FSI simulations.

THE two previous articles in this series have dealt respectively with a metal fabric‐covered aeroplane and a metal stressed‐skin machine, so that the Oxford, as an example of modern woodworking practice, forms a subject for direct comparison of the three main materials available. It will be remembered that the Air Council's policy of insisting upon all‐metal aeroplanes for military purposes was subjected to considerable criticism at the time of its inception some ten or twelve years ago. When the R.A.F. expansion was started the regulations were relaxed in regard to training machines and one general service type, which has resulted in the standardization of the Airspeed Oxford, de Havilland Tiger Moth, Miles Magister and Master I and the Avro Anson. All these types are built on well‐tried straightforward principles and they allow for the use of both material and labour upon which there is now comparatively little demand. Those firms which are producing wooden aeroplanes do, in fact, have far fewer delays caused by non‐delivery of parts and scarcity of labour—their rate of production is actually governed to a great extent by the delivery of metal parts and fittings—than do the producers of metal airframes.

THE first Canadair 50‐passenger twinjet airliner made its initial flight in May and has attracted considerable interest from a variety of operators. Advanced design of the aircraft began in 1987 with the fuselage being based on a 20 ft. extension of that of the CL‐601 Challenger. The first Regional Jet is now well into the flight test phase having attained Mach 0.7 and an altitude of 41,000 ft in initial trials as well as in‐flight shutdowns and starts on both engines at 30,000 ft and a similar exercise accomplished for the APU at 15,000 ft.

The gas containers of aircraft are made of fabric coated with solutions or varnishes of phenyl resin, commonly known under the Trade Mark “Bakelite.” The varnish is softened with castor oil, tricresyl phosphate, triphenyl phosphate or other suitable softener, and sprayed, painted or calendered on to the fabric. The varnish may be thinned with acetone. The softening and thinning medium may be varied within wide limits. Four different formulae illustrating suitable mixings are given in the Specification.