A High-order Compact Finite-difference Scheme for Large-eddy Simulation of Active Flow Control

A High-order Compact Finite-difference Scheme for Large-eddy Simulation of Active Flow Control
Author: Donald Pasquale Rizzetta
Publisher:
Total Pages: 106
Release: 2008
Genre: Eddies
ISBN:

A computational approach for performing large-eddy simulation (LES) of flows with active control is summarized. Simulation of these problems typically characterized by small-scale fluid structures cannot be carried out accurately by methods less sophisticated than LES. The numerical scheme is predicated upon an implicit time-marching algorithm, and utilizes a high order compact finite-difference approximation to represent spatial derivatives. Robustness of the scheme is maintained by employing a low-pass Pade-type non-dispersive spatial filter, which also serves as an implicit sub-grid turbulent model. Geometrically complex applications are accommodated by a high order overset grid technique. Utility of the method is illustrated by steady and pulsed approaches to suppression of acoustic resonance in supersonic cavity flow, leading-edge vortex control of a delta wing, efficiency enhancement of a transitional highly loaded low-pressure turbine blade, and separation control of a wall-mounted hump model. Where available, comparisons are also made with experimental data.

Direct and Large-Eddy Simulation I

Direct and Large-Eddy Simulation I
Author: Peter R. Voke
Publisher: Springer Science & Business Media
Total Pages: 438
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 940111000X

It is a truism that turbulence is an unsolved problem, whether in scientific, engin eering or geophysical terms. It is strange that this remains largely the case even though we now know how to solve directly, with the help of sufficiently large and powerful computers, accurate approximations to the equations that govern tur bulent flows. The problem lies not with our numerical approximations but with the size of the computational task and the complexity of the solutions we gen erate, which match the complexity of real turbulence precisely in so far as the computations mimic the real flows. The fact that we can now solve some turbu lence in this limited sense is nevertheless an enormous step towards the goal of full understanding. Direct and large-eddy simulations are these numerical solutions of turbulence. They reproduce with remarkable fidelity the statistical, structural and dynamical properties of physical turbulent and transitional flows, though since the simula tions are necessarily time-dependent and three-dimensional they demand the most advanced computer resources at our disposal. The numerical techniques vary from accurate spectral methods and high-order finite differences to simple finite-volume algorithms derived on the principle of embedding fundamental conservation prop erties in the numerical operations. Genuine direct simulations resolve all the fluid motions fully, and require the highest practical accuracy in their numerical and temporal discretisation. Such simulations have the virtue of great fidelity when carried out carefully, and repre sent a most powerful tool for investigating the processes of transition to turbulence.

Direct and Large-Eddy Simulation XI

Direct and Large-Eddy Simulation XI
Author: Maria Vittoria Salvetti
Publisher: Springer
Total Pages: 608
Release: 2019-02-02
Genre: Technology & Engineering
ISBN: 3030049159

This book gathers the proceedings of the 11th workshop on Direct and Large Eddy Simulation (DLES), which was held in Pisa, Italy in May 2017. The event focused on modern techniques for simulating turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structures, as Direct Numerical Simulation (DNS), Large-Eddy Simulation (LES) or hybrid models based on a combination of LES and RANS approaches. In light of the growing capacities of modern computers, these approaches have been gaining more and more interest over the years and will undoubtedly be developed and applied further. The workshop offered a unique opportunity to establish a state-of-the-art of DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows and to discuss about recent advances and applications. This volume contains most of the contributed papers, which were submitted and further reviewed for publication. They cover advances in computational techniques, SGS modeling, boundary conditions, post-processing and data analysis, and applications in several fields, namely multiphase and reactive flows, convection and heat transfer, compressible flows, aerodynamics of airfoils and wings, bluff-body and separated flows, internal flows and wall turbulence and other complex flows.

Numerical Techniques for Direct and Large-Eddy Simulations

Numerical Techniques for Direct and Large-Eddy Simulations
Author: Xi Jiang
Publisher: CRC Press
Total Pages: 284
Release: 2016-04-19
Genre: Mathematics
ISBN: 1420075799

Compared to the traditional modeling of computational fluid dynamics, direct numerical simulation (DNS) and large-eddy simulation (LES) provide a very detailed solution of the flow field by offering enhanced capability in predicting the unsteady features of the flow field. In many cases, DNS can obtain results that are impossible using any other me

High Accuracy Computing Methods

High Accuracy Computing Methods
Author: Tapan Sengupta
Publisher: Cambridge University Press
Total Pages: 589
Release: 2013-05-16
Genre: Computers
ISBN: 1107023637

""Presents methods necessary for high accuracy computing of fluid flow and wave phenomena in single source format using unified spectral theory of computing"--Provided by publisher"--

Supercomputing

Supercomputing
Author: Julian M. Kunkel
Publisher: Springer
Total Pages: 488
Release: 2013-06-12
Genre: Computers
ISBN: 3642387500

This book constitutes the refereed proceedings of the 28th International Supercomputing Conference, ISC 2013, held in Leipzig, Germany, in June 2013. The 35 revised full papers presented together were carefully reviewed and selected from 89 submissions. The papers cover the following topics: scalable applications with 50K+ cores; performance improvements in algorithms; accelerators; performance analysis and optimization; library development; administration and management of supercomputers; energy efficiency; parallel I/O; grid and cloud.

Flow Control Techniques and Applications

Flow Control Techniques and Applications
Author: Jinjun Wang
Publisher: Cambridge University Press
Total Pages: 293
Release: 2019
Genre: Science
ISBN: 1107161568

Master the theory, applications and control mechanisms of flow control techniques.

Unsteady Computational Fluid Dynamics in Aeronautics

Unsteady Computational Fluid Dynamics in Aeronautics
Author: P.G. Tucker
Publisher: Springer Science & Business Media
Total Pages: 432
Release: 2013-08-30
Genre: Technology & Engineering
ISBN: 9400770499

The field of Large Eddy Simulation (LES) and hybrids is a vibrant research area. This book runs through all the potential unsteady modelling fidelity ranges, from low-order to LES. The latter is probably the highest fidelity for practical aerospace systems modelling. Cutting edge new frontiers are defined. One example of a pressing environmental concern is noise. For the accurate prediction of this, unsteady modelling is needed. Hence computational aeroacoustics is explored. It is also emerging that there is a critical need for coupled simulations. Hence, this area is also considered and the tensions of utilizing such simulations with the already expensive LES. This work has relevance to the general field of CFD and LES and to a wide variety of non-aerospace aerodynamic systems (e.g. cars, submarines, ships, electronics, buildings). Topics treated include unsteady flow techniques; LES and hybrids; general numerical methods; computational aeroacoustics; computational aeroelasticity; coupled simulations and turbulence and its modelling (LES, RANS, transition, VLES, URANS). The volume concludes by pointing forward to future horizons and in particular the industrial use of LES. The writing style is accessible and useful to both academics and industrial practitioners. From the reviews: "Tucker's volume provides a very welcome, concise discussion of current capabilities for simulating and modellng unsteady aerodynamic flows. It covers the various pos sible numerical techniques in good, clear detail and presents a very wide range of practical applications; beautifully illustrated in many cases. This book thus provides a valuable text for practicing engineers, a rich source of background information for students and those new to this area of Research & Development, and an excellent state-of-the-art review for others. A great achievement." Mark Savill FHEA, FRAeS, C.Eng, Professor of Computational Aerodynamics Design & Head of Power & Propulsion Sciences, Department of Power & Propulsion, School of Engineering, Cranfield University, Bedfordshire, U.K. "This is a very useful book with a wide coverage of many aspects in unsteady aerodynamics method development and applications for internal and external flows." L. He, Rolls-Royce/RAEng Chair of Computational Aerothermal Engineering, Oxford University, U.K. "This comprehensive book ranges from classical concepts in both numerical methods and turbulence modelling approaches for the beginner to latest state-of-the-art for the advanced practitioner and constitutes an extremely valuable contribution to the specific Computational Fluid Dynamics literature in Aeronautics. Student and expert alike will benefit greatly by reading it from cover to cover." Sébastien Deck, Onera, Meudon, France

Applied Computational Aerodynamics

Applied Computational Aerodynamics
Author: Russell M. Cummings
Publisher: Cambridge University Press
Total Pages: 893
Release: 2015-04-27
Genre: Mathematics
ISBN: 1107053749

This book covers the application of computational fluid dynamics from low-speed to high-speed flows, especially for use in aerospace applications.

DNS of Wall-Bounded Turbulent Flows

DNS of Wall-Bounded Turbulent Flows
Author: Tapan K. Sengupta
Publisher: Springer
Total Pages: 393
Release: 2018-06-07
Genre: Technology & Engineering
ISBN: 9811300380

This book highlights by careful documentation of developments what led to tracking the growth of deterministic disturbances inside the shear layer from receptivity to fully developed turbulent flow stages. Associated theoretical and numerical developments are addressed from basic level so that an uninitiated reader can also follow the materials which lead to the solution of a long-standing problem. Solving Navier-Stokes equation by direct numerical simulation (DNS) from the first principle has been considered as one of the most challenging problems of understanding what causes transition to turbulence. Therefore, this book is a very useful addition to advanced CFD and advanced fluid mechanics courses.