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ONE of the most fundamental structural problems created by the advances in aircraft design during the past few years is that of the wing which is becoming progressively thinner and more highly loaded, and also demands higher degrees of surface finish, with accurate maintenance of contour throughout the load range. Stiffness becomes as important as strength, and the use of large angles of sweep‐back introduces the problem of torsional stiffness to a much greater degree than before. The natural result is that more and more of the load‐bearing part of the wing structure has to be placed in the surfaces of the aerofoil; the development from a fabric‐covered rib and spar structure to one in which the skin carries load, stressed‐skin construction that is, has to be carried further. The increased loadings necessarily increase the amount of structural material in the wing, so that skins can become thick enough to bear a high proportion of the load without buckling, the ultimate development being an aerofoil having two thick skins, with a light internal structure to help carry the shear stresses; this might be a honeycomb.

Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed.

First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation.

After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account.

The new jig-shape optimization method can be well used for the high aspect ratio wing.

The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

A Hollow propeller blade comprises a thrust member having an aerofoil portion with an external aerofoil thrust surface and a root portion which comprises two united sections, and a camber member united to the thrust member and having an external aerofoil camber surface. The root portion may comprise two united sections and the aerofoil section a third portion united to or integral with one of the sections. The root portion is formed in two sections 34, 36 welded together and each integral with a set of marginal ribs 18, 20 and intermediate ribs 22, 24, 26 which are complementary, the marginal ribs 18, 20 on the lower section 36 being stepped at 38, 40 to receive shorter marginal ribs on the section 34. Continuation ribs on the blade portion 42 are welded transversely to the ribs on the root portions, preferably using triangular inserts at the joins. The root portions 34, 36 may be of unequal size, the division being on a plane spaced from the neutral axis of the blade, the ribs of the upper portion being short and stub‐like, and the aerofoil part 42 may be integral with the lower root portion 36.

This study aims to optimize the manufacturing process to improve the manufacturing quality, costs and delivering time with the help of multiscale multiphysics modelling and simulation. Multiscale multiphysics-based modelling and simulations are receiving more and more interest by research community and the industry particularly in the context of increasing demands for manufacturing high precision complex products and understanding the intrinsic complexity in associated manufacturing processes.

In this paper, some modelling and analysis techniques using multiscale multiphysics modelling are presented and discussed.

Furthermore, the possibility of adopting the multiscale multiphysics modelling and simulation to develop the virtual machining system is evaluated, and further supported with an industrial case study on abrasive flow machining (AFM) of integrally bladed rotors using the techniques and system developed.

With the development of multiscale multiphysics-based modelling and simulation, it will enable effective and efficient optimisation of manufacturing processes and further improvement of manufacturing quality, costs, delivery time and the overall competitiveness.

A power unit for aircraft and the like comprising, an internal combustion engine, a variable pitch propeller, a supercharger for said engine, a compressor, a series of combustion chambers surrounding said compressor and connected to be supplied by said compressor, each of said combustion chambers terminating rearwardly in a propulsion jet, means for clutching said propeller to be driven by said engine, and drive means connecting said engine to the drive shafts of said supercharger and said compressor.

A stressed skin leading edge structure for aircraft wings and the like; comprising a unitary metal sheet formed to define a spanwise extending hollow leading edge structure of aerofoil cross section, a preformed core of low density material separately shaped to fit and completely fill the hollow interior of said leading edge structure and forming the sole support for said skin, a layer of air drying adhesive between the interior surface of said metal sheet and the exterior surface of said core, the rear edges of said metal sheet being supported by spanwise extending stiffeners adapted to define faying edges for attaching said leading edge structure to the centre section of an aircraft wing or the like.

An aeroplane has wings provided with a vane member formed of two hinged sections pivotally secured at the end of one section to the wing and adapted to be moved into and out of contact with the wing surface for the purpose of modifying the air flow thereover, and a pilot flap arranged in advance of the vane member for controlling the amount of air impinging thereon. In one form. Figs. 2 and 5, an aeroplane wing is provided with vanes 23, 24 nested in the extrados surface and flaps 25 nested in the intrados surface. Each vane 23 comprises an upper section 26 connected to the wing structure by a pivoted link 30 and also pivoted to a lower section 27 pivoted to the aerofoil structure. The vane nests into a recess having a cover member 34, and is actuated by toggle links 35, 36. A nested pilot flap 40 is disposed forward of vane 23 and is actuated by toggle links 42, 43. Vane 24 and flap 25 each includes a single surface 75 positioned in an aperture 76 in the wing and pivoted adjacent its rear edge to the wing structure. Closures 78 restrict entry of air into the wing when the surface is projected. The surfaces are braced by hinged links 79 and are actuated by toggle links 83, 84. Pilot flaps 103, 112 are arranged in front of elements 24 and 25, respectively. Fig 10 shows diagrammatically the control system for the elements 23, 24, 25, which are arranged in sets on either side of the body. The control means are such that any element of a set may be operated independently or all elements operated conjointly. The actuating means for the sections of vane 23 comprises a cable 56 secured to hinge 38 of toggle links 35,36 from the front and secured at its other end to a pulley 52, and a cable 58 secured to hinge 38 from the rear and to a pulley 53 at its other end. Pulleys 52, 53 are adapted to be rotated in unison by means of a toothed quadrant 55, meshed with a pinion 54 fast with pulleys 52, 53. Quadrant 55 is formed with a hand lever 48. Means to operate these hand levers simultaneously comprises a plate 65 having a handle 67, which plate is located above levers 48 and normally held clear therefrom, Fig. 9, by springs 64 and is adapted when depressed to engage therewith by means of apertures formed in the plate, whereafter rearward swinging of the plate imparts movement to all three levers and quadrants. The operating means for surfaces 24 and 25 and for the three sets of pilot flaps are of similar construction. According to a modification, Fig. 3, a wing with a backswept leading edge is provided with three vanes 23 and three flaps 25, the inner and outer flaps of the latter set tapering in chord toward the fuselage and wing tip, respectively. In another modification, Fig. 4, a wing is provided with one vane 23 and two vanes 126 similar to vane 23 but opening forwardly instead of rearwardly. In a further modification, Fig. 12, a wing is formed with a through air passage 140 adapted to be opened and closed by vanes 144, 145 of similar construction to vanes 23 of Fig. 5, but opening forwardly. U.S.A. Specification 2,005,965 is referred to.

These details and drawings of patents granted in the United States are taken, by permission of the Department of Commerce, from the ‘Official Gazette of the United States Patent Office’. Printed copies of the full specifications can be obtained, price 25 cents each, from the Commissioner of Patents, Washington, D.C., U.S.A. They are usually available for inspection at the British Patent Office, Southampton Buildings, Chancery Lane, London, W.C.2.

A helicopter rotor wherein each blade 3 carries a tip propulsion‐jet unit 4 has each unit constructed to reduce the velocity and noise level of the propulsive jets. Each unit 4 consists of an outer casing formed into a double wall at its forward end to provide an annular duct 12 which communicates through an aperture 20 with a conduit which extends through each blade from a gas producing plant 22, consisting of a gas turbine engine or engines or a separate compressor driven by such engine(s). Arms 10 secured radially on the forward end of the fairing support a central faired body 9 which is connected at its rear end to the fairing by stator blades 18 mounted ahead of a bladed rotor 5 secured in body 9 by a bearing 11. Blades 6 of rotor 5 carry a shroud ring formed on its periphery with turbine blades 8. Further stator blades 14, 15 connect the casing 4 to a tail fairing cone 16 and stator blades 13 bridge the duct 12. In operation gas flow from the blade conduit passes into duct 12 to be directed over blades 8 to drive rotor 5 which draws air through the unit to mix with the gases from gas producing plant 22 with a consequent reduction in jet velocity and noise. Any one of the rows of fan rotor and stator blades may be angularly adjustable to control the rotor speed. Alternatively, the turbine rotor blades 8 may be of the impulse type and a variable area admission nozzle used.

These details of British Patent Specifications are taken by permission from ‘Abridgments of Specifications—Patents for Inventions’. Copies of the full specifications are obtainable front the Patent Office, 25 Southampton Buildings, London, W.C.2, price 3s. 6d. each.