FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1961
1961 - 1339.PDF
FLIGHT, 14 September 1961 443 TRIPARTITE CONFERENCE... Surface erosion is shown to be dependent on the dynamic pressureof the outward flow of air along the surface and the type of surface involved. Although research has indicated some pertinent factorsinvolved in the problems of surface erosion and recirculation of debris, experience with higher-performance V/STOL aircraft underoperational conditions is required to determine to what extent the utility of the aircraft will be compromised by these problems. It is shown that the tendency to slide or blow over objects aroundthe take-off and landing area may actually be less for the higher performance types than for the helicopter because of the morerapid decay of the higher-velocity slipstreams and because of the thinner sheet of air flowing along the ground. The effect of the ground on the hovering lift of various V/STOLaircraft types is discussed, and it is shown that the ground effect can be favourable, adverse, or negligible, depending upon theparticular geometry of the aircraft and the location of the slip- streams with respect to the airframe. Research so far has alsoindicated that slipstream recirculation can have pronounced effects on the handling qualities of V/STOL aircraft flying near the ground. Some Considerations in Selecting VTOL Propulsion Systems, by A. P. ADAMSON and D. COCHRAN (General Electric Company,Flight Propulsion Laboratory Department) This paper presents a review of the engine characteristics which must be considered inselecting the best engine for a VTOL aeroplane. Most attention is devoted to jet-lift, turbofan lift, and tip-turbine fan-lift enginessuitable for high-speed aeroplanes. Comparisons between noise, exhaust temperature, exhaust velocity, engine weight, enginevolume, and engine frontal area are given. Engine-out safety, aircraft control power provisions, and take-off to cruise powermatching are discussed. H. C. Luttmao^QAI secretary, and C. H. E. Warren, head of General SupersonicsDivisit)n,*RAE Farnborough A second part of the paper presents test data from the General Electric-US Air Force-US Army|NASA lift fan and diverter valve research programme, including ^diverter valve performance, fan inlet performance, model pitch moment data, fan acceleration thrust, fan lift, fan speed variation, and representative fan-lifted aeroplane configurations. The Inverted Turbojet, by D. L. MORDELL (Dean of the Faculty ofEngineering), F. W. EYRE (Department of Mechanical Engineering) and A. V. SREENATH (Assistant Professor of the Department of I.C.Engineering, Indian Institute of Science, Bangalore, and attached to the Mechanical Engineering Department), all of McGill University.The inverted turbojet, in which the usual sequence of components is changed to give the sequence intake-turbine-heat exchanger-compressor-combustion chamber-nozzle, has been analysed thermo- dynamically and its development problems and possible applicationsare discussed. It appears that this engine, alone among the pure air-breathingengines, can provide useful thrust from standstill to at least a Mach number of 6, possibly higher in due time. While not as good,at a given speed, as various other air-breathing engines, its per- formance potential at high speeds is in fact quite good, and it has aunique advantage in offering the possibility of giving tremendous, shaft power, at hypersonic speeds, at very high thermal efficiency. Aerodynamic and Propulsion Considerations of Minimum-fieldAircraft, by P. L. SUTCLIFFE and V. K. MERRICK (Hawker SiddeleyAviation Ltd) and A. R. HOWELL (National Gas Turbine Establish-ment) The main theme of the paper is a discussion of the broad aerodynamic and propulsion aspects of flight at the very low speedsthat are necessary for performances within the meaning of "mini- mum field." It opens with a proposal for a universal classificationof airfield distance which could remove much of the ambiguity of many comparisons now made under the general heading ofV/STOL. The paper is then divided into two parts: Part I discusses thepossibility of generalizing the aerodynamic lift and drag require- ments for flight at very low speeds and the influence of thrustdeflection in this regime. This is followed by an investigation of airfield performance in the minimum-field category. The compari-son between airfield performance requirements and the generalized aerodynamic requirements then leads to a relatively simple classi-fication of the aircraft characteristics required for various degrees of V/STOL performance. Part I concludes with a brief discussionof the implications of controllability on engine thrust requirements when direct or indirect engine thrust is used to augment the normalaerodynamic controls. Sir George Edwards, RAC executive director, and Robert L Boer, P & W manager Part II deals with the turbofan and turbojet configurations likelyto be used for V/STOL applications. Particular attention is paid to the all-important question of engine weight. Some considerationis given to the illustration penalties and to the provision of the higher installed thrusts that are required to cover hot and high controland other conditions. General aspects of the noise problem are dealt with. Transports of the Future—a Systems Approach, by GEORGE C. PRILL and HAROLD HOEKSTRA (respectively, Director, FlightStandards Service, and Chief, Aeronautics Branch, Aviation Research and Development Service, Federal Aviation Agency) The super-sonic transport will probably be a part of the air transportation system of the next decade. A "system" approach similar to thatused in the development of a weapons system is essential to ensure safety, reliability, and low operating costs. The characteristicsof the supersonic transport must permit its. blending into a mixed operation of subsonic passenger jets, cargo aircraft, and VTOLshort-haul aircraft. The mistakes of the past must be studied and not repeated. It is suggested that the traditional concept,of airworthiness bebroadened into a new concept of "systemworthiness." The super- sonic transport must be systemworthy, and so must every othercomponent of the system, if success is to be attained. Maj G. P. Rulman, late hon treasurer of RAeS, with Dr Wright In a systemworthiness concept, the sonic boom, airport noise,overall runway length and strength requirements, the air traffic system and other elements must be considered. Further, weatherlimitations must be completely overcome. The supersonic transport must be able to cope not only with the traditional enemies of icing
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
