Valuable Studiesdoi: 10.1108/eb032488pmid: N/A
THE present term has seen the inauguration at Cambridge of a new college for women undergraduates, additional to the long‐existing Girton and Newnham. The foundation of New Hall—as it is called—might perhaps be thought of as intrinsically only of indirect interest to readers of AIRCRAFT ENGINEERING; though it is not improbable that sooner or later some of its graduates will make aeronautics their careers.
The Spinning of Modern AircraftKerr, T.H.
doi: 10.1108/eb032489pmid: N/A
SPINNING is a rather complicated subject but it is possible to present quite a broad view without going into too much detail so that one can appreciate the way in which the various characteristics of the aircraft can affect the motion both during the spin and in the recovery from the spin. In the following notes an attempt has been made to do this in a way which, it is hoped, will be helpful to the designer and the flight technician and pilot.
High Offset Flapping Pin Rotor AnalysisPayne, P.R.
doi: 10.1108/eb032490pmid: N/A
The theory of rotor dynamics given in Ref. 1 is extended to include the effects of coupling between feathering and flapping (δ3 angle) and flapping hinge offset. Both introduce considerable modification to the classic equations, and instead of simple explicit equations for flapping amplitudes, coning angle, collective pitch and inflow angles, five simultaneous equations have now to be solved. Data sheets have been constructed which enable this to be done quickly and accurately for any design of linearly tapered and twisted blade. It is suggested that the intelligent use of such data sheets is of great assistance in a design office, not only because of the very considerable time savings achieved, but also because they eliminate the most fruitful sources of error in numerical calculation. It is shown that a high offset rotor enables much higher speeds to be achieved with a conventional helicopter—an effect which has already been fairly well publicized. A penalty is paid for this in the form of hub pitching moments which have to be balanced out externally; either by the use of two rotors, offset C.G., aerodynamic surfaces, or inclination of the mechanical axis. These effects will be considered in detail in a further article. Finally, equations are developed for a convenient method of calculating blade elemental angle of attack which is claimed to be superior to classic methods for design office purposes.
Energy Theorems and Structural AnalysisArgyris, J.H.
doi: 10.1108/eb032491pmid: N/A
IT is natural in reviewing the developments of Sections 3 and 4 to inquire if it is possible to enlarge upon the conception of complementary work and strain energy in a similar way as accomplished for work and strain energy by the introduction of virtual displacements.
A Note on the Escalator ProcessMorris, J.; Head, J.W.
doi: 10.1108/eb032492pmid: N/A
If an algebraic polynomial equation has roots which are negative if real and have negative real parts if complex, the coefficients must satisfy certain fundamental conditions originally formulated by Routh. These conditions are here derived by comparatively simple algebra for the sextic equation by a method which can be generalized; its extension to equations of the eighth and tenth degree is indicated. The case of damped Lagrangian frequency equations is considered as an appropriate epilogue.
A Descriptive Geometry Solution of Some Undercarriage ProblemsBialkowski, L.S.
doi: 10.1108/eb032493pmid: N/A
This Paper presents a few examples of Descriptive Geometry applied to the Undercarriage design:(1) Retraction mechanism geometry.(2) A method of checking clearances between moving undercarriage parts and the surrounding structure.(3) The control by an undercarriage leg, or any other swinging member, of another swinging member, when their axes of rotation are in different planes in space.
Research Reports and Memorandadoi: 10.1108/eb032495pmid: N/A
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued
Trade Announcementsdoi: 10.1108/eb032496pmid: N/A
A.P.V.‐Paramount Ltd., Wandsworth Park, S.W. 18, announce that Mr J. F. B. Jackson, B.Sc, A.R.I.C., F.I.M., has joined their Board as director in charge of their new foundries producing castings in special steels and non‐ferrous alloys, that were opened at Crawley, Sussex, early last year. Mr Jackson has relinquished his position as Director of the British Steel Castings Research Association.
Month in the Patent Officedoi: 10.1108/eb032497pmid: N/A
Components such as propeller or helicopter rotor blades, wings, or structural members consist of an outer shell of thin metal, plastic or plywood, with an internal supporting filling of low density (about 4 lb./cu. ft.) and having a closed cellular structure formed by expanding a thermoplastic material such as polyrinyl chloride, incorporating a hardening agent such as phenol formaldehyde or urea resin or a paint‐hardening material. The manufacturing process is carried out in two stages, the mix for the internal filling being first placed in a mould similar in shape to, but smaller than, the outer shell, and then heated sufficiently to cause the mix to fill the mould, from which it is then removed and allowed to cool to a solid‐like mass having a similar shape to the outer shell. The cooled mass is then inserted in the shell and heating continued until the gases liberated expand the mass to fill the shell and apply internal pressure thereto, to impart the desired rigidity to the member.