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Item Open Access Ablation studies of low melting point bodies in a pre-heated supersonic air stream(College of Aeronautics, 1960-02) Cleaver, J. W.This report is an investigation into the melting of axi-symmetric and two-dimensional bogies at a Mach No. of M[infinity] = 1.78 and stagnation temperatures up to 550 [degrees]K. In this temperature range, the most suitable material for the models was found to be an eutectic tin-lead alloy a melting point of 456 [degrees]K. For the cone and hemisphere-cone models two distinct modes of melting were observed. In cases where the estimated equilibrium surface temperature (Tw)o was approximately equal to the material melting temperature Tm, melting occurred only at the stagnation point of the model and was such that a flat surface normal to the gas stream always resulted. If the average rate of heat transfer at the air-liquid interface be defined as qi = LmPm x, where Lm is the latent heat of fusion, Pm is the density of the material and x is the rate of recession of the flat surface, it is found that qi decreases with increase of the radius of the flat nose. A very approximate theory is found to show some agreement with the experimental rates of heat transfer. When (Tw)o was considerably greater than Tm the flat surface was no longer preserved and the resulting steady ablating shape was paraboloidal in nature. When this occurred x was usually constant. This allowed some average steady state heat transfer rates to be evaluated and compared with theory. Preliminary tests were also made with a two-dimensional wedge model.Item Open Access Addendum to a theoretical and experimental study of the boundary layer flow on a 45 degrees swept back wing(College of Aeronautics, Cranfield, 1957-11) Walton, J.COA report 109 describes Flight Tests carried out on a swept back half wing of double elliptical section to investigate the nature of the boundary layer flow, with particular reference to Bounday Layer Instability and subsequent transition.Item Open Access Addendum to type record. Avro "Lancaster" Mk.1 P. A. 474 Type record No. 1/P1/Lancaster. Investigation of boundary layer conditions on wings. M.O.S. Contract No.6/Aircraft/9807/C. B. 6(a)(College of Aeronautics, 1956-01) College of Aeronautics, Department of Aircraft DesignIntroduction The investigation involves, briefly, the mounting of a wing of 45' sweep-back in a dorsal position on the fuselage of 'Lancaster' P.A.474 such that wing incidence will be variable in flight over a 20 range, i.e. ± 100. A ‘partial chord’ technique for swept wings has been established by the College using a similar wing mounting configuration on an Avro 'Anson' Aircraft and this technique has been applied to the current investigation.Item Open Access Aerodynamic characteristics of a hypersonic parachute(College of Aeronautics, 1961-11) Boyd, E. A.Newtonian theory, both in the form of the Modified-Newtonian and the Newton- Busemann pressure laws, is used to find the shape, cloth area and drag of the axisymmetric canopy of a hypersonic parachute, whose only load-carrying fibres are longitudinal ones. As an example, an estimate is made of the size of canopy needed to give a drag of 20,000 lb. in flight at a Mach number of 10 at 100,000 feet altitude.Item Open Access Aerodynamic characteristics of a swept wing with spanwise blowing.(Cranfield University, 1956-09) Ayers, R. F.; Wilde, M. R.This report is the first of a series of studies to investigate the effectiveness of a spanwise blowing on the aerodynamic characteristics of low aspect ratio wings and bodies. The model used in this investigation was an untapered half-wing aspect ratio 1.39,50 degree sweep back, and mounted on a reflective plate.Item Open Access The aerodynamic derivatives of an aerofoil oscillating in an infinite staggered cascade(College of Aeronautics, 1960-01) Craven, A. H.Thin aerofoil theory is used to obtain, in integral form the aerodynamic derivatives of an aerofoil oscillating in an infinite cascade. The theory allows for arbitrary stagger angle and phase difference between adjacent blades of the cascade. The expressions obtained reduce, for zero stagger and for in phase and antiphase oscillations, to known results.Item Open Access The aerodynamic derivatives with respect to rate of yaw for a delta wing with small dihedral at supersonic speeds(College of Aeronautics, Cranfield, 1949-03) Hunter-Tod, J. H.Expressions are derives for the yawing derivatives on the assumptions of the linearised theory of flow for a delta wing with small dihedral flying at supersonic speeds at small incidences. The non-dimensional derivatives are numerically decreasing functions of Mach number. The non-dimensional rolling and yawing derivatives are also numerically decreasing functions of aspect ratio. When the wing lies entirely within the apex Mach cone there is a leading edge suction force proportional to incidence which makes a destabilising contribution to the yawing moment and side force which may be of the same magnitude as that from the inducted excess pressure distribution.Item Open Access The aerodynamic derivatives with respect to sideslip for a delta wing with small dihedral at supersonic speeds(College of Aeronautics, 1947-12) Robinson, A.; Hunter-Tod, J. H.Expressions are derived for the sideslip derivatives on the assumptions of the linearised theory of flow for a delta wing with small dihedral flying at supersonic speeds. A discussion is included in the appendix on the relation between two methods that have been evolved for the treatment of aerodynamic force problems of the delta wing lying within its apex Mach cone. Continues…Item Open Access Aerofoil theory for swallow tail wings of small aspect ratio(College of Aeronautics, Cranfield., 1950-10) Robinson, A.A method is developed for the calculation of the aerodynamic forces acting on a ‘swallow tail’ wing of small aspect ratio. Lift, induced drag, and aerodynamic centre position of simple swallow tail wings (Fig. 1 (b)) are computed as an application. For a given incidence, lift and induced drag are, within the limits of the theory, proportional to aspect ratio and independent of speed. The chordwise life distribution rises linearly from zero at the apex, drops rapidly in the region of the root chord trailing edge, and then decreases gently to zero.Item Open Access Aileron reversal and divergence of swept wings with special consideration of the relevant aerodynamic and elastic characteristics(College of Aeronautics, Cranfield, 1952-03) Radok, J. R. M.Using oblique coordinates, the static problems of Aero-elasticity for swept wings are reduced to the solution of integral – or matrix equations, which may be solved by iteration. The present treatment also indicates the suitability of integral equations for fundamental aero-elastic investigations. Continues …Item Open Access The air resistance of racing cyclists(College of Aeronautics, Cranfield, 1956-10) Nonweiler, T.Tests in the closed-section wind-tunnel on three different cyclists mounted on a racing bicycle are described, and figures quoted for the recorded air resistance. Some comments are also included on the implications of the results concerning the power-output of racing cyclists.Item Open Access Aircraft parameter identification using Matlab(2000)System identification techniques are routinely used in experimental stability and control studies throughout the aerospace industry. Over the years, various researchers at the College of Aeronautics have contributed to this field; most recently some of the latest methods have been employed to estimate the stability and control derivatives of a variety of aircraft types. Although the more recent investigations provide a useful insight into the capabilities and characteristics of several up-to-date methods, they have not resulted in tools which may be used on a routine basis. Consequently, the purpose of this report is to describe a set of procedures which are straightforward to apply, and produce reasonable solutions to the type of linear parameter identification problems which are often found in aerospace work. Recordings of the short period and phugoid modes from Handley-Page Jetstream G-NFLC are used throughout as examples. Firstly, those characteristics of the aircraft’s instrumentation system which influence the quality of the signals - sample rate, antialiasing filters, time delays - are considered. This information is used in conjunction with standard signal processing techniques to ensure that the data is of sufficient quality to be used in the parameter estimation process. Next, a basic Fourier analysis and a least squares algorithm are employed to produce non- parametric and parametric models respectively. The results thus obtained are comparable to those generated using more sophisticated techniques. In conclusion, standard signal processing methods combined with relatively simple estimation theory offer an adequate solution to the linear parameter estimation problem.Item Open Access Analysis of experiments on swept wing structures(College of Aeronautics, Cranfield, 1953-05) Howe, D.This report is concerned with the application of various theories to the solution of problems investigated experimentally, and in some cases theoretically, by others at the College of Aeronautics. Continues …Item Open Access The analysis of reinforced circular and elliptical cutouts under various loading conditions(College of Aeronautics, 1961-07) Houghton, D. S.; Rothwell, A.The effect of reinforced cutouts in a plane sheet under various loading conditions is considered, and a number of experimental results are given for circular and elliptical cutouts with a uniform plate reinforcement, subjected to various systems of biaxial tension and pure shear. These experiments were conducted using a plane loading frame, and the results are compared with the theoretical plane stress solution. For the circular cutout the effect of neglecting the bending stiffness of the reinforcement is considered. Some additional experiments were carried oUt on a 60 in. diameter pressurised cylinder containing an elliptical hole reinforced according •to Mansfield's neutral hole theory. The strains in the sheet in the region of the neutral hole are .compared with the corresponding strains in the uncut sheet. The experimental results obtained generally show a good agreement with the theory.Item Open Access An analysis of the flight dynamics of a second generation SST aircraft(1999) Steer, Anthony J.This interim report covers an initial overview of delta-wing aircraft static, dynamic and control characteristics, collated from publications within the public domain and the authors related research. This is to give the reader an overall understanding how a delta-winged supersonic transport aircraft’ s characteristics differ to those of a conventional civil transport aircraft. This is followed by identifying the aircraft’s static and dynamic stability, with the effect of speed and CG location on the aircraft dynamic modes specifically addressed. Following this, a comprehensive investigation and analysis of the open loop response of a SCT baseline aircraft, in both low-speed cruise and approach and landing conditions, has been carried out. Both time and frequency domain techniques have been utilised. Finally, conclusions are made based on the results of the work presented.Item Open Access Analysis of two-cell swept box with ribs parallel to the line of flight under loading by constant couples(College of Aeronautics, Cranfield, 1953-03) Howe, D.The method of oblique co-ordinates is used to analyse the problem associated with the strength and deformation of a uniform, rectangular, two- cell swept box beam having ribs parallel to the line of flight. The case of loading by constant couples is considered, but no account of root effects is taken. Continues…Item Open Access The application of a C* flight control law to large civil transport aircraft(1993) Field, EdmundThe work contained in this report is part of an on-going programme of research into handling qualities of fly-by-wire civil transport aircraft currently being undertaken within the Flight Dynamics Group of the College of Aeronautics . Although much work has been undertaken into handling qualities of military aircraft over the last 30 years, civil aircraft have received considerably less attention. Over the last decade civil transport aircraft incorporating fly-by-wire flight control systems have been introduced into commercial operation, the latest including some modified aerodynamic designs. However the civil arena lacks the supporting research into handling qualities that the military side has enjoyed. More recently the civil side is beginning to receive the attention it deserves with work in Europe by Fokker and the Group for Aeronautical Research and Technology in EURope (GARTEUR), for example. In the United States much work has been done by the manufacturers such as Boeing and McDonnell Douglas, and as ever work supported by the US Air Force and NASA. The primary aim of this current programme is to design flight control laws to give fly-by-wire civil transport aircraft excellent flying qualities at all flight conditions, but especially in piloted flight phases. The most critical flight phase of a civil transport is that of the landing approach, and, as with other studies of this type, this phase receives the greatest attention in this study. This report concerns an analysis of the C* parameter. The C* criterion was one of the first handling qualities criteria designed to take account of advanced aerodynamic designs of modern aircraft and higher order systems introduced by flight control systems. Several aircraft have since employed control laws based around the C* parameter. A proportional feedback C* controller was applied to a Boeing 747-100 in landing approach configuration, and assessed against the C* criterion and the US military specification MIL-STD- 1797A.Item Open Access The application of memo-motion to industrial operations(College of Aeronautics, Cranfield., 1954-12) Norbury, C. J.Memo-Notion, or Spaced Shot Photography, was introduced as a tool of Work Study Dr. Mundel, then of Purdue University, in 1946, as a means of reducing the cost of film analysis on long operations by using a camera driven by a geared down electric motor, giving exposures every second. Since its introduction Memo-Motion has been applied to a limited extent in the U.S.A., but it is not known to be in use at all in England.Item Open Access Application of the linear perturbation theory to compressible flow about bodies of revolution(College of Aeronautics, Cranfield, 1947-09) Young, A. D.; Kirkby, S.The linearised theory is developed in some detail in order to clarify the differences between two-dimensional and axi-symmetric flow. In agreement with other authors it is concluded that the perturbation velocity on a thin body of revolution in compressible flow is 1/β2 times the perturbation velocity in incompressible flow on a thinner body at reduced incidence obtained by reducing the lateral dimensions of the original body in the ratio (3:1). This result is applied to a representative family of streamline bodies of revolution at zero incidence. Continues…Item Open Access The applications of computational fluid dynamics to problems in rotorcraft aerodynamics:(1995) Shaw, ScottThe flowfield around a helicopter rotor in forward flight is intrinsically unsteady and contains many complex interacting flow phenomena. As a consequence experimental investigations are difficult to perform, difficult to interpret and costly. There is a clear need for reliable computational methods whose uncertainties are less than those of experiment. In this paper computational methods currently available for the solution of problems in rotor aerodynamics are examined and the current direction of research in this field identified.