Download or read book Scalar Mixing in Turbulent Flow written by Carl Hunter Gibson and published by . This book was released on 1962 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experiments on Passive Scalar Mixing in Turbulent Flows with Different Velocity and Scalar field Boundary Conditions written by Jason Lepore and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The findings suggest that both the mean flow shear and turbulence intensity of the velocity field play an important role in determining the mixedness of the scalar field." --
Download or read book Turbulence in Mixing Operations written by Robert Brodkey and published by Elsevier. This book was released on 2012-12-02 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence in Mixing Operations: Theory and Application to Mixing and Reaction presents a summary of the current status of research on turbulent motion, mixing, and kinetics. Each chapter of this book discusses turbulence in the context of mixing and reaction in scalar fields. Chapters I and III discuss the classification of turbulent reacting systems and the different possibilities in this context. Chapter II reviews the properties of passive mixing. Chapter IV looks at turbulent mixing in chemically reactive flows. Chapter V uses different techniques to make parallel numerical calculations of both mixing and reaction. Finally, Chapter VI reviews turbulence and actual industrial mixing operations. This book will be of great value for chemical and industrial engineers, especially for those interested in turbulent and industrial mixing.
Download or read book Statistics and Scaling Laws of Turbulent Scalar Mixing at High Reynolds Numbers written by and published by Cuvillier Verlag. This book was released on 2014-06-26 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The turbulent motion of fluids and scalars is a highly complex problem. It is still one of the unsolved problems of classical physics, cf. Nelkin (1992) and Shraiman and Siggia (2000), and the description remains challenging. The understanding of turbulent flows and turbulent mixing is of great interests for many applications. Prominent examples are the turbulent combustion of chemical reactants and the dynamics of the atmosphere or the oceans. In those cases the evolution of the scalar affects the turbulent flow itself. Here, we focus on the case where the scalar is both conserved and passive and does not affect the flow field.
Download or read book A Four dimensional Experimental Study of Passive Scalar Mixing in Turbulent Flows written by Kenneth B. Southerland and published by . This book was released on 1994 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Turbulent Scalar Mixing by Means of a Combination of PIV and LIF written by Lourens Aanen and published by Delft University Press. This book was released on 2002-01-01 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents of this doctoral dissertation include: Mixing (scaling). Turbulent flow field (pipe flow). Axisymmetric flows (Reynolds stress modeling). Principles of PIV and LIF. Flow facility. Laser light sheet. Measurement systems. Point source measurements, velocity field, concentration field, combined PIV/LIF measurements, scalar fluxes. The mixing process in an axisymmetric turbulent let using PIV and LIF. Conclusions. Bibliography
Download or read book FINE SCALE STRUCTURE OF CONSERVED SCALAR MIXING IN TURBULENT SHEAR FLOWS SC MUCH GREATER THAN 1 AND SC APPROXIMATELY EQUAL TO 1 SCHMIDT NUMBER MOLECULAR MIXING written by KENNETH ALVAN BUCH (JR.) and published by . This book was released on 1991 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: the local instantaneous values of a conserved scalar and its dissipation rate.
Download or read book Measurement of the Three dimensional Scalar Mixing Spectrum in Turbulent Pipe Flow written by Bernard A. Toseland and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Mixing in Nonreactive and Reactive Flows written by S. Murthy and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence, mixing and the mutual interaction of turbulence and chemistry continue to remain perplexing and impregnable in the fron tiers of fluid mechanics. The past ten years have brought enormous advances in computers and computational techniques on the one hand and in measurements and data processing on the other. The impact of such capabilities has led to a revolution both in the understanding of the structure of turbulence as well as in the predictive methods for application in technology. The early ideas on turbulence being an array of complicated phenomena and having some form of reasonably strong coherent struc ture have become well substantiated in recent experimental work. We are still at the very beginning of understanding all of the aspects of such coherence and of the possibilities of incorporating such structure into the analytical models for even those cases where the thin shear layer approximation may be valid. Nevertheless a distinguished body of "eddy chasers" has come into existence. The structure of mixing layers which has been studied for some years in terms of correlations and spectral analysis is also getting better understood. Both probability concepts such as intermittency and conditional sampling as well as the concept of large scale structure and the associated strain seem to indicate possibilities of distinguishing and synthesizing 'engulfment' and molecular mixing.
Download or read book Multi scalar Mixing in Turbulent Coaxial Jets written by Alais Hewes and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "An experimental investigation of multi-scalar mixing in turbulent coaxial jets is presented herein. The first part of this work involves the development of a thermal-anemometry-based probe to simultaneously measure two scalars and velocity in turbulent flows. The work of Hewes (2016) on the simultaneous measurement of velocity and helium concentration is extended, and the necessary and optimal design parameters for thermal-anemometry-based probes capable of making such measurements are refined in the current work. An analysis of measurements from different interference probes reveals that, unlike what has previously been reported in the literature, hot-wires of differing diameters are not required for concurrent velocity and concentration measurements. Furthermore, both theoretical arguments and experiments in flows of varying helium concentration are used to demonstrate that the cold-wire thermometer is effectively insensitive to helium concentration. The temperature field can therefore be measured independently of the velocity or concentration fields. This has important implications for interference probes, since the cold-wire can be used to compensate for temperature effects on these probes, allowing them to be used in non-isothermal flows. Consequently, it is shown that an interference probe can be combined with a cold-wire thermometer to form a novel 3-wire probe to simultaneously measure velocity, helium concentration, and temperature in a turbulent flow. \\ \indentIn the second part of this work, the novel 3-wire probe is used to study the evolution of multiple scalars in turbulent coaxial jets consisting of (i) a center jet containing a mixture of helium and air, (ii) an annular jet containing pure (unheated) air, and (iii) a coflow of (pure) heated air. The flow can be viewed as containing three scalars: $\phi_1$, normalized helium concentration, $\phi_2$, pure, unheated air in the annular jet (which is inferred from measurements of the other two scalars), and $\phi_3$, normalized temperature. Measurements are performed along axis of the jets for three different momentum ratios ($M_2/M_1=0.77$, $M_2/M_1=2.1$, and $M_2/M_1=4.2$). Mean and rms quantities, covariances, velocity-scalar triple moments, probability density functions (PDFs), joint probability density functions (JPDFs), and conditional expectations of the fluctuating velocity are measured. Three distinct regions are identified along the axis of the coaxial jets: (i) the potential core of the center jet, consisting primarily of $\phi_1$, (ii) the inner mixing region, dominated by large fluctuations of anti-correlated $\phi_1$ and $\phi_2$, and (iii) the fully merged region, where the coaxial jets behave similarly to a single jet. In this final region, one can observe that $\phi_1$ and $\phi_3$, and $\phi_2$ and $\phi_3$, become progressively anti-correlated in the downstream direction, whereas $\phi_1$ and $\phi_2$ become progressively more correlated. Increasing the momentum ratio ($M$) initially causes $\phi_1$ and $\phi_2$ to mix more quickly, however, examination of the JPDFs suggest that far downstream, these effects may be reversed. Furthermore, distinct differences are observed between coaxial jets in which $M1$ and those in which $M1$, most likely resulting from the fact that the annular jet is entrained into center jet in the former, whereas the center jet is entrained into annular jet in the latter. Finally, it is worth pointing out that $M$ may have a significant effect on the shapes and distributions of the scalar-scalar JPDFs, even where the correlation coefficients of different cases have converged to similar values. Thus, the need for simultaneous multi-scalar measurements when studying multi-scalar mixing is emphasized"--
Download or read book Towards Understanding Turbulent Scalar Mixing written by Sharath S. Girimaji and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fine Scale Structure of Conserved Scalar Mixing in Turbulent Shear Flows written by Kenneth Alvan Buch and published by . This book was released on 1991 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Second Order Modelling of Scalar Mixing with Scalar Intermittency written by Clinton L. Dancey and published by . This book was released on 1984 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing of a Passive Scalar in Isotropic and Sheared Homogeneous Turbulence written by E. Shirani and published by . This book was released on 1981 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to calculate the velocity and passive scalar fields in homogeneous turbulent flows, the three-dimensional, time-dependent equations of motion and the diffusion equation have been solved numerically.
Download or read book Mixing written by H. Chaté and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixing may be thought of as the operation by which a system evolves from one state of simplicity (initial segregation) to another state of simplicity (complete uniformity). Between these two extremes, complex patterns emerge and die. Questions naturally arise- how can the geometry of complex patterns be characterised, what is the time scale of the process, what structures are involved in the flow? This volume, comprising the proceedings of the NATO ASI on Mixing, attempts to address these questions from the approaches of geometry, kinetics and structure. The ASI which brought together diverse communities with a common interest in the problem of mixing, now provides us with a comprehensive work on the problem of mixing.
Download or read book A Study of Passive Scalar Mixing in Turbulent Boundary Layers Using Multipoint Correlators written by Ronald J. Miller and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study analyzes a turbulent passive scalar field using two-point and three-point correlations of the fluctuating scalar field. Multipoint correlation functions are investigated because they retain scaling property information and simultaneously probe the concentration field for the spatial structure of the scalar filaments. Thus, multipoint correlation functions provide unique information about the spatial properties of the concentration filaments. The concentration field is created by the iso-kinetic release of a high Schmidt number dye into a fully developed turbulent boundary layer of an open channel flow. The concentration fields were previously measured using the planar laser-induced fluorescence technique. The two-point correlations of the fluctuating scalar field indicate that as the scalar field evolves downstream, the anisotropic influence of the tracer injection method diminishes, and the scalar field becomes dominated by the mean velocity shear. As the scalar filaments align with the mean velocity gradient, the elliptical shape associated with the contours of the correlation function tilts in the direction of the mean velocity gradient. As a result, the two-point correlation contours of the concentration fluctuations indicate that anisotropic conditions (i.e. the tilted, asymmetric, elliptical shape) develop as a consequence of the mean velocity shear. Three-point correlations of the fluctuating scalar field are calculated based on configuration geometries defined by previous researchers. The first configuration follows Mydlarski & Warhaft (1998), which employs two cold-wire measurements and Taylor's frozen turbulence hypothesis. The three-point correlation contours of the concentration fluctuations associated with the cold-wire measurements exhibit a symmetric characteristic V-shape. Similar symmetric properties are observed in the current study. The second set of configurations follows on recent theoretical predictions, which indicate that the three-point correlation of the fluctuating scalar field is dependent on the size, shape, and orientation of the triangle created by the three points. The current study analyzes two geometric configurations (isosceles and collinear). The geometric configurations are defined to ensure that the influence of the shape remains constant as the configuration is rotated, translated, and dilated. Additionally, the scaling exponent in the inertial-convective regime is calculated to determine the dependence of the correlation function on the size of the triangle pattern.
Download or read book Coarse Grained Simulation and Turbulent Mixing written by Fenando F. Grinstein and published by Cambridge University Press. This book was released on 2016-06-30 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews our current understanding of the subject. For graduate students and researchers in computational fluid dynamics and turbulence.
