An elasticity solution is presented for the three layered all round simply supported rectangular plate subjected to a uniformly distributed normal load. Numerical results have been obtained by selecting parameters such that they are applicable for sandwich plates. A detailed comparison of these results has been made with the results of sandwich plate theory developed by Monforton and Ibrahim.

The Euler equations are proving to be an appropriate model for in viscid vortex flow. This paper demonstrates the range of this model’s applicability by presentation of flowfields computed around a number of different wings with either sharp or rounded edges at transonic and supersonic speeds. The emphasis here is on the physics of the flow model rather than the numerical aspects of the solution method. The results display both expected as well as unexpected vortex phenomena and they indicate the value of this computational tool. Particular attention is paid to the wake regions.

A theoretical solution is given for the overall buckling and wrinkling of sandwich circular rings when subjected to a uniform radial pressure loading. The core is in the form of a honeycomb material, and the faces can be made from laminated fibre reinforced plastics, which exhibit coupling between bending and stretching. The elasticity equations for both the orthotropic core and faces are satisfied, and it is found that the problem is governed by four simultaneous differential equations for the displacements of the faces. A solution is obtained by assuming simple sine and cosine functions for these displacements. Minimum critical pressures are found numerically and results are given which show the dependence on face thickness, core thickness and mean radius. A procedure is suggested for finding approximate solutions for sandwich rings subjected to more general loading conditions.

We consider the effects of atmospheric disturbances, such as wind, shears, turbulence and wakes, on the aerodynamics of aircraft, in order (§1) to quantify the phenomena in question, and provide a basis for future application to problems of performance and stability. The present method of description of the effects of non-uniformity and unsteadiness of the incident flow on aircraft aerodynamics, is presented in some detail for a head- or tailwind sheared vertically (§2), and its extension to all three components of velocity and six shear derivatives is outlined (§11). The starting point (§3) is the relative life change due to a uniform or sheared wind; in the latter case we introduce (§6) a dimensionless shear number S, which plays with regard to vorticity, a role similar (§6) to the Mach and Reynolds numbers respectively in connection with compressibility and viscosity. The aerodynamics of a body or aerofoil in an incident stream containing vorticity, is specified (§7) by a shear coefficient Cs, playing a role similar to the lift, drag and moment coefficients for aerodynamic forces and torques. The present theory is consistent with the formulas of theoretical aerodynamics, the results of wind tunnel tests and observation of atmospheric disturbances involving shear flows. The use of the concepts of shear number S and shear coefficient Cs allows the calculation (§10) of the uniform wind equivalent to a given shear, ie, the wind velocity which would cause the same lift change as the shear. This equivalent wind may be useful in the calculation of the aerodynamic effects of sheared flows, eg, forebody vortices on a wing, wing in a propeller slipstream, tailplane in a wing’s wake, an aircraft landing, behind another, or flight through storms or microbursts.

A sequence of high Reynolds number two-dimensional entry flow problems is considered by varying the form of the entry profile from one representing uniform shear to one representing different parts of a Poiseuille profile. The detailed development of the entry flow is illustrated in a few cases. The entry length, pressure drop, and pressure loss in the entry region are given in each case.

The ‘sliding block’ asymmetric nozzle, which is mechanically simple and robust, is ideal for a small, variable Mach number supersonic wind tunnel installation, due the fact that it is affordable and relatively easy to manufacture. Until now there has been no rational procedure for selecting the correct nozzle profiles to satisfy certain predetermined nozzle performance criteria, ie, a range of operating Mach numbers and an acceptable test section flow non-uniformity over the given range. The present paper considers the minimum requirements which are sufficient and necessary to design an asymmetric nozzle and shows that these can be met by nozzles defined in terms of a shape parameter, an angular parameter and a length parameter. The lower end of the range of operating Mach numbers is determined by the choice of the overall flow turning angle. For a family of nozzles defined by a particular shape parameter, an heuristic analysis indicates how the test section flow non-uniformity must vary as a function of a variable which is a particular grouping of the angular and length parameters, and the range of operating Mach numbers. The dependence of the nozzle performance on the parameters is investigated numerically, assuming inviscid flow and utilising the method of characteristics. The result shows that the best nozzle shape is where the flow is expanded very rapidly immediately downstream of the throat. For a particular family of nozzles, the numerical analysis shows the complex relationship between nozzle performance and the angular and length parameters, which is best described in a graphical representation. As a result, the task of selecting correct profiles for sliding block nozzles is reduced to simply selecting the appropriate values of nozzle parameters from the curves supplied.