Large Eddy Simulation of Acoustic Propagation in Turbulent Flow Through Ducts and Mufflers

Large Eddy Simulation of Acoustic Propagation in Turbulent Flow Through Ducts and Mufflers
Author: Nishant Kumar Singh
Publisher:
Total Pages:
Release: 2012
Genre:
ISBN:

This research involves study of acoustic propagation of pulse in a simple expansion muffler, which is very often used in HVAC or automotive exhausts. A hybrid pressure-based compressible solver is developed and validated for a low Mach number flow simulation of acoustic pulse. This new solver is developed using C++ based OpenFOAM toolkit and further tested for low Mach number flow test case. The analysis of simple expansion muffler for various structures, frequency ranges and numerical schemes is performed and results are summarized. RANS simulation of duct and muffler with mean flow is conducted and results are presented with inherent limitations associated with the method. Further, a mixed synthetic inflow boundary condition is also developed and validated for LES of channel flow. The mixed synthetic boundary is then used for LES of a simple expansion muffler to analyse the flow-acoustic and acoustic-pulse interactions inside the expansion muffler. The improvement in the prediction of tonal noise and vortex shedding inside the chamber is highlighted in comparison to the RANS method. Further, the effect of forced pulsation on flow-acoustic is observed in regard to the shift in Strouhal number inside the simple expansion muffler. Finally, a set of benchmark results for experimental analysis of the simple expansion muffler both, with and without flow is obtained to compare attenuation in forced pulsation for various mean-flow velocities. These experimental results are then used for validation of the proposed pressure-based compressible solver.

Direct and Large-Eddy Simulation X

Direct and Large-Eddy Simulation X
Author: Dimokratis G.E. Grigoriadis
Publisher: Springer
Total Pages: 523
Release: 2017-10-06
Genre: Technology & Engineering
ISBN: 3319632124

This book addresses nearly all aspects of the state of the art in LES & DNS of turbulent flows, ranging from flows in biological systems and the environment to external aerodynamics, domestic and centralized energy production, combustion, propulsion as well as applications of industrial interest. Following the advances in increased computational power and efficiency, several contributions are devoted to LES & DNS of challenging applications, mainly in the area of turbomachinery, including flame modeling, combustion processes and aeroacoustics. The book includes work presented at the tenth Workshop on 'Direct and Large-Eddy Simulation' (DLES-10), which was hosted in Cyprus by the University of Cyprus, from May 27 to 29, 2015. The goal of the workshop was to establish a state of the art in DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows. The book is of interest to scientists and engineers, both in the early stages of their career and at a more senior level.

Large-Eddy Simulation for Acoustics

Large-Eddy Simulation for Acoustics
Author: Claus Wagner
Publisher: Cambridge University Press
Total Pages: 389
Release: 2007-01-15
Genre: Technology & Engineering
ISBN: 1139463160

Noise around airports, trains, and industries attracts environmental concern and regulation. Large-eddy simulation (LES) is used for noise-reduced design and acoustical research. This 2007 book, by 30 experts, presents the theoretical background of acoustics and LES, and details about numerical methods, e.g. discretization schemes, boundary conditions, and coupling aspects.

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows
Author: P. Sagaut
Publisher: Springer Science & Business Media
Total Pages: 600
Release: 2006
Genre: Computers
ISBN: 9783540263449

First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Mathematics of Large Eddy Simulation of Turbulent Flows

Mathematics of Large Eddy Simulation of Turbulent Flows
Author: Luigi Carlo Berselli
Publisher: Springer Science & Business Media
Total Pages: 378
Release: 2006
Genre: Computers
ISBN: 9783540263166

The LES-method is rapidly developing in many practical applications in engineering The mathematical background is presented here for the first time in book form by one of the leaders in the field

Direct and Large-Eddy Simulation IV

Direct and Large-Eddy Simulation IV
Author: Bernard Geurts
Publisher: Springer Science & Business Media
Total Pages: 554
Release: 2001-11-30
Genre: Technology & Engineering
ISBN: 9781402001772

This volume contains the proceedings of the 2001 DLES4 workshop. It describes and discusses state-of-the-art modeling and simulation approaches for complex flows. Fundamental turbulence and modeling issues but also elements from modern numerical analysis are at the heart of this field of interest.

Direct and Large-Eddy Simulation VI

Direct and Large-Eddy Simulation VI
Author: E. Lamballais
Publisher: Springer Science & Business Media
Total Pages: 783
Release: 2006-10-19
Genre: Technology & Engineering
ISBN: 1402051522

The sixth ERCOFTAC Workshop on ‘Direct and Large-Eddy Simulation’ (DLES-6) was held at the University of Poitiers from September 12-14, 2005. Following the tradition of previous workshops in the DLES-series, this edition has reflected the state-of-the-art of numerical simulation of transitional and turbulent flows and provided an active forum for discussion of recent developments in simulation techniques and understanding of flow physics.

Large Eddy Simulation of Wall Bounded Turbulent Flows with Heat Transfer

Large Eddy Simulation of Wall Bounded Turbulent Flows with Heat Transfer
Author: Yang Liu
Publisher:
Total Pages: 274
Release: 2002
Genre:
ISBN:

In this thesis work, large eddy simulation was used to study a variety of wall-bounded turbulent flows using a compressible finite volume formulation. Subgrid scale terms in both momentum and energy equations were modeled dynamically. Furthermore, due to the inhomogeniety of wall-bounded flows, the model was further localized to better represent the physics of the problem. The model was first applied to study the incompressible turbulent flow through a duct with square cross-section. Mean flow, law of the wall, and turbulence statistics were compared with the benchmark results of direct numerical simulation and excellent agreement was achieved. The secondary flow in the cross-section was captured. It is composed of four pairs of counter-rotating cells. The interaction between mean and secondary flow fields creates some important features and they were studied in this work. Based on incompressible duct flow, system rotation was applied to investigate the effects of rotation on the turbulent flow field. The system rotation was found to reduce turbulence level on the leading side, while increase turbulence level on the trailing side. Because of the rotation, the secondary flow field in non-rotating duct was found to be diminished at weaker rotation and even eliminated at stronger rotation. Instead, a pair of counter rotating cells called Taylor-Görtler vortices, as well as the Taylor-Proudman regime, was found to exist in the cross-section, which is consistent with the results of the literature. Large eddy simulation was also applied to investigate the effects of ribs and system rotation on heat transfer in a channel. It was found that a rib creates recirculation zones near the rib. The turbulence level is at its maximum near the ribs. The existence of ribs enhances heat transfer significantly over the plane channel, as well as creates low-heat-transfer-coefficient region in the recirculation zones. This means a balance is needed between global enhancement and local suppression. With system rotation, heat transfer is greatly enhanced on the trailing side, while significantly reduced on the leading side.

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows
Author: Pierre Sagaut
Publisher: Springer Science & Business Media
Total Pages: 326
Release: 2013-03-09
Genre: Science
ISBN: 3662044161

First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."