Abstract: Numerical investigations of flow past rotating circular cylinders with and without wires wrapped on the surface of the cylinder were studied using Computational Fluid Dynamics (CFD). The flow characteristics such as flow separation, shedding of the primary and secondary vortices, and drag coefficients were investigated. The software STAR CCM+ from Siemens PLM was used in all investigations. Three-dimensional Unsteady Reynolds Average Navier Stokes (URANS) equations were utilized. The free stream mean velocity was constant at 10 m/sec, which corresponded to an approximate Reynolds number based on cylinder’s diameter of 32,000. The results are presented for cylinders with and without wires at varying rotation rates [alpha] of 0, 0.5, and 1. This is represented by [alpha], the ratio of the tangential velocity at the cylinder to that of the free stream velocity of the flow. As the rotation rate increased from 0 to 1, the drag coefficient for the smooth rotating cylinder reduced, while the drag coefficient for the wire-wrapped cylinder increased. The wire-wrapped cylinder produced significantly higher lift when compared with the corresponding value for the smooth cylinder. Increasing the rotation rate increases the lift and lift to drag ratio.

Abstract: The objective of the present study is to investigate the characteristics of a flow around a rotating circular cylinder with and without an end plate near a wall boundary. The different cases which are taken into consideration in the current investigations were with gap ratios of 0.1d, 0.5d, 1.0d, 1.5d and 2.0d. A symmetric end plate is attached behind the rotating circular cylinder at a distance of 0.1d from the cylinder and a gap ratio of 1.5d. We performed Computational Fluid Dynamics (CFD) simulation of the flow around a rotating circular cylinder near a plane wall boundary using a CFD solver, STAR-CCM+. Free-stream velocity is kept constant at 5 m/s and the Reynolds number calculated is 3.24X10 4 . We then studied the flow characteristics such as lift and drag generated on the circular cylinder with and without an end plate and the wake structure. We observed that the vortex suppression is increased when the gap ratio is reduced, i.e., when the circular cylinder is nearer to the plane wall boundary. As the gap ratio increases the drag force generated decreases and the lift force increases considerably. In the case of rotating circular cylinder with an end plate, the wake area has moved upwards and the lift generated has increased manifold.

Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows.Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries.Traditional fluid and flow dynamics titles offer the essential background but generally include very sparse coverage of rotating flows—which is where this book comes in. Beginning with an accessible introduction to rotating flow, recognized expert Peter Childs takes you through fundamental equations, vorticity and vortices, rotating disc flow, flow around rotating cylinders and flow in rotating cavities, with an introduction to atmospheric and oceanic circulations included to help deepen understanding.Whilst competing resources are weighed down with complex mathematics, this book focuses on the essential equations and provides full workings to take readers step-by-step through the theory so they can concentrate on the practical applications. - A detailed yet accessible introduction to rotating flows, illustrating the differences between flows where rotation is significant and highlighting the non-intuitive nature of rotating flow fields - Written by world-leading authority on rotating flow, Peter Childs, making this a unique and authoritative work - Covers the essential theory behind engineering applications such as rotating discs, cylinders, and cavities, with natural phenomena such as atmospheric and oceanic flows used to explain underlying principles - Provides a rigorous, fully worked mathematical account of rotating flows whilst also including numerous practical examples in daily life to highlight the relevance and prevalence of different flow types - Concise summaries of the results of important research and lists of references included to direct readers to significant further resources

This text offers an authoritative compilation of experimental data, theoretical models, and computer simulations which will provide the reader with a comprehensive survey of research work on the phenomenon of flow around circular cylinders.

This book discusses the subject of wave/current flow around a cylinder, the forces induced on the cylinder by the flow, and the vibration pattern of slender structures in a marine environment.The primary aim of the book is to describe the flow pattern and the resulting load which develops when waves or current meet a cylinder. Attention is paid to the special case of a circular cylinder. The development in the forces is related to the various flow patterns and is discussed in detail. Regular as well as irregular waves are considered, and special cases like wall proximities (pipelines) are also investigated.The book is intended for MSc students with some experience in basic fluid mechanics and for PhD students.

Topics in Numerical Analysis II contains in complete form, the papers given by the invited speakers to the Conference on Numerical Analysis held under the auspices of the National Committee for Mathematics of the Royal Irish Academy at University College, Dublin from 29th July to 2nd August, 1974. In addition, the titles of the contributed papers are listed together with the names and addresses of the authors who presented them at the conference. This book is divided into 20 chapters that present the papers in their entirety. They discuss such topics as applications of approximation theory to numerical analysis; interior regularity and local convergence of Galerkin finite element approximations for elliptic equations; and numerical estimates for the error of Gauss-Jacobi quadrature formulae. Some remarks on the unified treatment of elementary functions by microprogramming; application of finite difference methods to exploration seismology; and variable coefficient multistep methods for ordinary differential equations applied to parabolic partial differential equations are also presented. Other chapters cover realistic estimates for generic constants in multivariate pointwise approximation; matching of essential boundary conditions in the finite element method; and collocation, difference equations, and stitched function representations. This book will be of interest to practitioners in the fields of mathematics and computer science.