R. E. D. Bishop

The Lift and Drag Forces on a Circular Cylinder Oscillating in a Flowing Fluid.

A circular cylinder was placed in a flowing fluid with its axis across the stream. The fluctuating lift and drag forces, and the steady drag force were measured. The results for the stationary cylinder were given in a previous paper (Bishop & Hassan 1964). Here, the results are described and summarized for a cylinder that is made to oscillate transversely in a direction perpendicular to the stream.

The lift and drag forces on a circular cylinder in a flowing fluid

Apparatus is described for measuring directly fluctuating lift and drag forces and steady mean drag force. These forces are exerted upon a cylinder placed so that its central axis is perpendicular to the direction of flow of water in a channel. Results are given for the stationary cylinder for the range of Reynolds number 3600 to 11 000.

An investigation into the theory of resonance testing

Many vibrating systems are subject to damping forces arising from the structure of the system itself, and in the simpler theories this damping is assumed to be linear. The first part of the paper (§§ 1 to 5) is devoted to a discussion of systems with n degrees of freedom subject to linear damping. In the remainder of the paper various resonance testing techniques are assessed in the light of this general theory.

The Vibration and Balancing of an Unbalanced Flexible Rotor

The motion of a flexible unbalanced rotating shaft is examined. The effects of balancing such a shaft (as a ‘rigid body’) in a conventional low-speed balancing machine are explained. The underlying...

The Vibration of Rotating Shafts

This paper is the first of a series whose purpose is to relax the usual assumptions in the analysis of shaft vibration. The formulation of a more complete theory suggests a method of balancing flexible shafts, a fresh approach to problems of stability and a way of allowing for bearing characteristics; it also suggests methods of allowing for lack of axial symmetry. Following a suggestion due to Johnson (1, 2)†, the theory is developed in simple terms. Use is made in this exposition of the mechanical analogy which exists between an initially bent shaft and a simple conical pendulum whose point of support is given a circular motion in a horizontal plane.

Coupled bending and twisting of a timoshenko beam

Abstract Allowance is made for shear deflection and for rotary inertia of a non-uniform beam that executes coupled bending and twisting vibration. Principal modes are found, orthogonality conditions established and modal equations of forced motion derived.

On the dynamics of linear non-conservative systems

A number of results are presented, relating to the matrix equation Aq̣̈ + Bq̇ + Cq = Q(t). It is not assumed that the system matrices A, B and C possess any of the familiar properties (of symmetry, skew symmetry or positive definiteness). These results relate to free motion in which Q(t) = 0, to forced harmonic motion in which Q(t) = ϕ eiωt and to transient vibration in which Q(t) is an arbitrary function of time.

The Vibration of Rotating Shafts Supported in Flexible Bearings

This paper deals with an axially symmetric system composed of a uniform or non-uniform flexible shaft rotating in flexible bearings. It is shown how natural frequencies and characteristic functions may be found, using data that have been presented previously. Systems having flexible bearings whose mass is negligible are shown to be simpler than those whose bearings are massive and a discussion of their free and forced motions is given. Free and forced motions of shafts supported in massive bearings are shown to demand special treatment and an analytical approach is explained for each.

A Critical Introduction to Some Industrial Resonance Testing Techniques

This paper gives details of apparatus which was designed to permit an initial appraisal to be made of methods of resonance testing. A fairly lightly damped system with widely spaced natural frequen...

Free and forced oscillation of a vertical tube containing a flowing fluid

A flexible vertical tube, clamped at its upper end and carrying a nozzle at its free lower end, can become unstable when a liquid flows down it. The system is a convenient one for the study of passage through an instability boundary as it is amenable to theoretical and experimental investigation of both free and forced oscillation. This paper presents the results of a theoretical and experimental study of the motions with special reference to the instability boundary.