A method is presented for the calculation of the streamwise component of vorticity, for flows in rotating passages. The method may be regarded as an extension of the methods applied in recent years to the calculation of secondary flows in stationary passages.

Attention is concentrated on the quantity I=p+½ρV2−½ρU2, where V is the fluid velocity relative to the rotor and U is the rotor tangential velocity. I remains constant along a streamline in the rotor, and is found to enter into the equation for the generation of vorticity in much the same way as the total head enters for flow in stationary passages.

An approximate calculation of the streamwise vorticity generated in a simple axial-flow rotor is made, and qualitative consideration is given to the flow in a centrifugal impeller. Just as for the calculation of secondary flows in stationary passages, an approximate shape of the streamline must be assumed before the secondary flows can be calculated.

By using the methods of the Calculus of Finite Differences, expressions are obtained for the nodal moments and deflections of a simply-supported grillage, subjected to a loading constant along one set of beams and having a sinusoidal variation along the other set of beams. A simple example verifies the expressions and illustrates their use.

Effects of vibrational excitation and dissociation of air on inviscid high speed flow past a circular cone, at zero incidence, with an attached shock wave, are studied on the assumption of thermal equilibrium. A numerical solution of the problem is outlined and an approximate analytic solution for the flow between the surface of the cone and the shock wave is developed. Two numerical examples are given as an illustration and compared with the corresponding solutions assuming constant air properties.

Mr H FUCHS was born in Czechoslovakia in 1930 and emigrated to this country in 1939 He was educated at Northampton Grammar School, and obtained his Honours Degree in Physics at the Manchester University in 1952 Prior to obtaining his Ph D in Electronics, on the subject of helicopter computers in ground resonance, at Southampton University, he was employed in the Guided Weapons Laboratory at Vickers Armstrongs as an Electronic Engineer Since 1956 he has been with Blackburn and General Aircraft as Chief Electronic Engineer in charge of the Electronic Laboratory and the Electronic Design of Aircraft His work has included the design and production of Blackburn's analogue computer, and is currently engaged in designing an airborne analogue digital converter, fully transistorised, and associated electronic data handling equipment to a system of flight testing of aircraft

The Chairman, in introducing the Author, described the subject of his paper as one of paramount importance to all who were concerned in the design and operation of helicopters Mr Rogers was an indentured aeronautical engineer apprentice at the Fairey Aviation Company from 1940 to 1946, during which time he obtained the Ordinary and Higher National Certificates in Mechanical and Aeronautical Engineering He was awarded an S B A C scholarship to the College of Aeronautics in 1946 and obtained a diploma with distinction in Aircraft Design

The paper first discusses the analysis of a general vector field with the aid of the concept of the field line with its tangent, principal normal and binormal. Detailed applications are made to the motion of inviscid and of viscous fluids.

The influence of higher-harmonic deflection components on the creep-buckling characteristics of an idealised H-section column is investigated. The creep properties of the material of the column are defined by a simple power-function creep law. The results show that higher-harmonic deflection components reduce the column lifetime significantly only when their initial amplitudes, as well as the initial amplitude of the first harmonic component, are very large. Furthermore, it is shown that second-harmonic components have a much smaller effect on the column behaviour than do third-harmonic components.

The thrust magnitude programme of a rocket missile being supposed specified, the problem is solved of programming the thrust direction to achieve maximum range on the Earth's surface. Earth curvature and rotation, and variation of gravity with height are taken into account, but air resistance is neglected. Motion is assumed to take place in the Equatorial plane. Tables are included from which the optimal trajectories of missiles may be computed when two design parameters are known and these tables are used to assess the advantage to be gained at extreme ranges by firing in the sense of the Earth's rotation rather than against it.

Some new solutions for steady incompressible laminar boundary layer flow, obtained by Gortler, have been used to test the accuracy of two methods which are commonly used to predict separation. A modification of Stratford's criterion for separation is given in this paper and is probably the most accurate and the simplest of all methods at present in use. Modified numerical functions are also given for Thwaites's method of predicting the main characteristics of the boundary layer over the whole surface, which improve the accuracy of the method.

The compressible flow past an oscillating two-dimensional aerofoil in a wind tunnel with porous walls is considered, using linearised theory. The porous wall is assumed to have the property that the ratio of the normal velocity at the wall to the pressure drop across the wall is constant. Transform theory is used to find the supersonic longitudinal stability derivatives, and an extension of Possio's integral equation for the quasi-stationary case in subsonic flow.