Direct Numerical Simulation of Incompressible Pipe Flow Using a B-Spline Spectral Method

Direct Numerical Simulation of Incompressible Pipe Flow Using a B-Spline Spectral Method
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 168
Release: 2018-07-17
Genre:
ISBN: 9781723032103

A numerical method based on b-spline polynomials was developed to study incompressible flows in cylindrical geometries. A b-spline method has the advantages of possessing spectral accuracy and the flexibility of standard finite element methods. Using this method it was possible to ensure regularity of the solution near the origin, i.e. smoothness and boundedness. Because b-splines have compact support, it is also possible to remove b-splines near the center to alleviate the constraint placed on the time step by an overly fine grid. Using the natural periodicity in the azimuthal direction and approximating the streamwise direction as periodic, so-called time evolving flow, greatly reduced the cost and complexity of the computations. A direct numerical simulation of pipe flow was carried out using the method described above at a Reynolds number of 5600 based on diameter and bulk velocity. General knowledge of pipe flow and the availability of experimental measurements make pipe flow the ideal test case with which to validate the numerical method. Results indicated that high flatness levels of the radial component of velocity in the near wall region are physical; regions of high radial velocity were detected and appear to be related to high speed streaks in the boundary layer. Budgets of Reynolds stress transport equations showed close similarity with those of channel flow. However contrary to channel flow, the log layer of pipe flow is not homogeneous for the present Reynolds number. A topological method based on a classification of the invariants of the velocity gradient tensor was used. Plotting iso-surfaces of the discriminant of the invariants proved to be a good method for identifying vortical eddies in the flow field. Loulou, Patrick and Moser, Robert D. and Mansour, Nagi N. and Cantwell, Brian J. Ames Research Center DIGITAL SIMULATION; COMPUTERIZED SIMULATION; COMPUTATIONAL FLUID DYNAMICS; INCOMPRESSIBLE FLOW; PIPE FLOW; FINITE ELEMENT METHOD; TURBULENT FLOW; ...

Fundamentals of Computational Fluid Dynamics

Fundamentals of Computational Fluid Dynamics
Author: H. Lomax
Publisher: Springer Science & Business Media
Total Pages: 256
Release: 2013-03-09
Genre: Science
ISBN: 3662046547

The chosen semi-discrete approach of a reduction procedure of partial differential equations to ordinary differential equations and finally to difference equations gives the book its distinctiveness and provides a sound basis for a deep understanding of the fundamental concepts in computational fluid dynamics.

Computational Fluid Dynamics

Computational Fluid Dynamics
Author: Jiri Blazek
Publisher: Elsevier
Total Pages: 491
Release: 2005-12-20
Genre: Science
ISBN: 0080529674

Computational Fluid Dynamics (CFD) is an important design tool in engineering and also a substantial research tool in various physical sciences as well as in biology. The objective of this book is to provide university students with a solid foundation for understanding the numerical methods employed in today's CFD and to familiarise them with modern CFD codes by hands-on experience. It is also intended for engineers and scientists starting to work in the field of CFD or for those who apply CFD codes. Due to the detailed index, the text can serve as a reference handbook too. Each chapter includes an extensive bibliography, which provides an excellent basis for further studies.

Vortex Flows and Related Numerical Methods

Vortex Flows and Related Numerical Methods
Author: J.T. Beale
Publisher: Springer Science & Business Media
Total Pages: 385
Release: 2013-04-18
Genre: Technology & Engineering
ISBN: 9401581371

Many important phenomena in fluid motion are evident in vortex flow, i.e., flows in which vortical structures are significant in determining the whole flow. This book, which consists of lectures given at a NATO ARW held in Grenoble (France) in June 1992, provides an up-to-date account of current research in the study of these phenomena by means of numerical methods and mathematical modelling. Such methods include Eulerian methods (finite difference, spectral and wavelet methods) as well as Lagrangian methods (contour dynamics, vortex methods) and are used to study such topics as 2- or 3-dimensional turbulence, vorticity generation by solid bodies, shear layers and vortex sheets, and vortex reconnection. For researchers and graduate students in computational fluid dynamics, numerical analysis, and applied mathematics.