A Study of the Development of Steady and Periodic Unsteady Turbulent Wakes Through Curved Channels at Positive, Zero, and Negative Streamwise Pressure Gradients, Part 1

A Study of the Development of Steady and Periodic Unsteady Turbulent Wakes Through Curved Channels at Positive, Zero, and Negative Streamwise Pressure Gradients, Part 1 PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723501067
Category :
Languages : en
Pages : 276

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The turbomachinery wake flow development is largely influenced by streamline curvature and streamwise pressure gradient. The objective of this investigation is to study the development of the wake under the influence of streamline curvature and streamwise pressure gradient. The experimental investigation is carried out in two phases. The first phase involves the study of the wake behind a stationary circular cylinder (steady wake) in curved channels at positive, zero, and negative streamwise pressure gradients. The mean velocity and Reynolds stress components are measured using a X-hot-film probe. The measured quantities obtained in probe coordinates are transformed to a curvilinear coordinate system along the wake centerline and are presented in similarity coordinates. The results of the steady wakes suggest strong asymmetry in velocity and Reynolds stress components. However, the velocity defect profiles in similarity coordinates are almost symmetrical and follow the same distribution as the zero pressure gradient straight wake. The results of Reynolds stress distributions show higher values on the inner side of the wake than the outer side. Other quantities, including the decay of maximum velocity defect, growth of wake width, and wake integral parameters, are also presented for the three different pressure gradient cases of steady wake. The decay rate of velocity defect is fastest for the negative streamwise pressure gradient case and slowest for the positive pressure gradient case. Conversely, the growth of the wake width is fastest for the positive streamwise pressure gradient case and slowest for the negative streamwise pressure gradient. The second phase studies the development of periodic unsteady wakes generated by the circular cylinders of the rotating wake generator in a curved channel at zero streamwise pressure gradient. Instantaneous velocity components of the periodic unsteady wakes, measured with a stationary X-hot-film probe, are analyzed by the ph...

A Study of the Development of Steady and Periodic Unsteady Turbulent Wakes Through Curved Channels at Positive, Zero, and Negative Streamwise Pressure Gradients, Part 1

A Study of the Development of Steady and Periodic Unsteady Turbulent Wakes Through Curved Channels at Positive, Zero, and Negative Streamwise Pressure Gradients, Part 1 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 276

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Effects of Periodic Unsteady Wake Flow and Pressure Gradient on Boundary Layer Transition Along the Concave Surface of a Curved Plate

Effects of Periodic Unsteady Wake Flow and Pressure Gradient on Boundary Layer Transition Along the Concave Surface of a Curved Plate PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 86

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Paper

Paper PDF Author:
Publisher:
ISBN:
Category : Mechanical engineering
Languages : en
Pages : 536

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Government Reports Announcements & Index

Government Reports Announcements & Index PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 434

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Unsteady Combustor Physics

Unsteady Combustor Physics PDF Author: Tim C. Lieuwen
Publisher: Cambridge University Press
ISBN: 1139576836
Category : Technology & Engineering
Languages : en
Pages : 427

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Book Description
Developing clean, sustainable energy systems is a pre-eminent issue of our time. Most projections indicate that combustion-based energy conversion systems will continue to be the predominant approach for the majority of our energy usage. Unsteady combustor issues present the key challenge associated with the development of clean, high-efficiency combustion systems such as those used for power generation, heating or propulsion applications. This comprehensive study is unique, treating the subject in a systematic manner. Although this book focuses on unsteady combusting flows, it places particular emphasis on the system dynamics that occur at the intersection of the combustion, fluid mechanics and acoustic disciplines. Individuals with a background in fluid mechanics and combustion will find this book to be an incomparable study that synthesises these fields into a coherent understanding of the intrinsically unsteady processes in combustors.

Two-Dimensional Separated Flows

Two-Dimensional Separated Flows PDF Author: S. M. Belotserkovsky
Publisher: CRC Press
ISBN: 9780849393068
Category : Technology & Engineering
Languages : en
Pages : 322

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Book Description
Two-Dimensional Separated Flows provides a systematic presentation of the theory of separated flow around bodies. The main classes of aerodynamic problems of plane-parallel flow around bodies are described, and the steady aerodynamic, unsteady aerodynamic, and statistical characteristics of a trailing wake are determined. Numerical methods based on the synthesis of models for non-viscous incompressible flow and boundary layer, algorithms, examples, and systematic comparisons are presented. The book also includes numerical results for the problem of separated flow around fixed, oscillating, and rotating cylinders, in addition to results for separated flow around an aerofoil over a wide range of angles. Two-Dimensional Separated Flows will benefit researchers and students studying aerodynamics, aircraft dynamics, aeroelasticity, and the aerodynamics of building structures.

Fluid Mechanics for Engineers

Fluid Mechanics for Engineers PDF Author: Meinhard T. Schobeiri
Publisher: Springer Science & Business Media
ISBN: 3642115942
Category : Technology & Engineering
Languages : en
Pages : 517

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Book Description
The contents of this book covers the material required in the Fluid Mechanics Graduate Core Course (MEEN-621) and in Advanced Fluid Mechanics, a Ph. D-level elective course (MEEN-622), both of which I have been teaching at Texas A&M University for the past two decades. While there are numerous undergraduate fluid mechanics texts on the market for engineering students and instructors to choose from, there are only limited texts that comprehensively address the particular needs of graduate engineering fluid mechanics courses. To complement the lecture materials, the instructors more often recommend several texts, each of which treats special topics of fluid mechanics. This circumstance and the need to have a textbook that covers the materials needed in the above courses gave the impetus to provide the graduate engineering community with a coherent textbook that comprehensively addresses their needs for an advanced fluid mechanics text. Although this text book is primarily aimed at mechanical engineering students, it is equally suitable for aerospace engineering, civil engineering, other engineering disciplines, and especially those practicing professionals who perform CFD-simulation on a routine basis and would like to know more about the underlying physics of the commercial codes they use. Furthermore, it is suitable for self study, provided that the reader has a sufficient knowledge of calculus and differential equations. In the past, because of the lack of advanced computational capability, the subject of fluid mechanics was artificially subdivided into inviscid, viscous (laminar, turbulent), incompressible, compressible, subsonic, supersonic and hypersonic flows.

Turbulence Models and Their Application

Turbulence Models and Their Application PDF Author: Tuncer Cebeci
Publisher: Springer Science & Business Media
ISBN: 9783540402886
Category : Science
Languages : en
Pages : 140

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Book Description
After a brief review of the more popular turbulence models, the author presents and discusses accurate and efficient numerical methods for solving the boundary-layer equations with turbulence models based on algebraic formulas (mixing length, eddy viscosity) or partial-differential transport equations. A computer program employing the Cebeci-Smith model and the k-e model for obtaining the solution of two-dimensional incompressible turbulent flows without separation is discussed in detail and is presented in the accompanying CD.

A Selection of Test Cases for the Validation of Large-eddy Simulations of Turbulent Flows

A Selection of Test Cases for the Validation of Large-eddy Simulations of Turbulent Flows PDF Author:
Publisher:
ISBN: 9789283610724
Category : Computational fluid dynamics
Languages : en
Pages : 198

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