Author
Roger E. A. Arndt
Bio: Roger E. A. Arndt is an academic researcher from University of Minnesota. The author has contributed to research in topics: Water tunnel & Cavitation. The author has an hindex of 35, co-authored 158 publications receiving 5153 citations.
Topics: Water tunnel, Cavitation, Vortex, Supercavitation, Wake
Papers published on a yearly basis
Papers
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Book•
01 Jan 1989
TL;DR: The state of the art in physics, modeling, and measurement of Turbulence can be found in this article, where the authors discuss the role of smoke visualization and hot-wire anemometry in the study of transition.
Abstract: Contents: The State of Turbulence Research.- Contributions of Numerical Simulation Data Bases to the Physics, Modeling, and Measurement of Turbulence.- The Self-Preservation of Turbulent Flows and Its Relation to Initial Conditions and Coherent Structures.- Engineering Turbulence Models.- Chaos and the Onset of Turbulence.- Advances in Turbulence Measurement Techniques.- The Role of Smoke Visualization and Hot-Wire Anemometry in the Study of Transition.- Index.
424 citations
395 citations
TL;DR: In this paper, the cavitating flow around a NACA66 hydrofoil is studied numerically with particular emphasis on understanding the cavitation structures and the shedding dynamics, including the cavity growth, break-off and collapse downstream.
335 citations
TL;DR: In this paper, the authors present an approach to solve the problem of the "missing link" problem in the context of artificial neural networks, and propose a method to solve it.
Abstract: Copyright Cambridge University Press. Published article may be found at http://journals.cambridge.org/action/displayAbstract?aid=13425.
316 citations
TL;DR: In this paper, it was shown that vortex core instabilities in microvortices are important factors in the erosion mechanisms associated with sheet/cloud cavitation. But, only limited attention paid to developed vortex cavitation was paid to the inception process.
Abstract: ▪ Abstract Cavitation in vortical structures is a common, albeit complex, problem in engineering applications. Cavitating vortical structures can be found on the blade surfaces, in the clearance passages, and at the hubs of various types of turbomachinery. Cavitating microvortices at the trailing edge of attached sheet cavitation can be highly erosive. Cavitating hub vortices in the draft tubes of hydroturbines can cause major surges and power swings. There is also mounting evidence that vortex cavitation is a dominant factor in the inception process in a broad range of turbulent flows. Most research has focused on the inception process, with limited attention paid to developed vortex cavitation. Wave-like disturbances on the surfaces of vapor cores are an important feature. Vortex core instabilities in microvortices are found to be important factors in the erosion mechanisms associated with sheet/cloud cavitation. Under certain circumstances, intense sound at discrete frequencies can result from a coupli...
308 citations
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Book•
01 Jan 1996TL;DR: In this article, the authors present a review of rigor properties of low-dimensional models and their applications in the field of fluid mechanics. But they do not consider the effects of random perturbation on models.
Abstract: Preface Part I. Turbulence: 1. Introduction 2. Coherent structures 3. Proper orthogonal decomposition 4. Galerkin projection Part II. Dynamical Systems: 5. Qualitative theory 6. Symmetry 7. One-dimensional 'turbulence' 8. Randomly perturbed systems Part III. 9. Low-dimensional Models: 10. Behaviour of the models Part IV. Other Applications and Related Work: 11. Some other fluid problems 12. Review: prospects for rigor Bibliography.
2,920 citations
TL;DR: In this paper, the first analytical description of anomalous scaling laws in turbulent transport has been obtained and the underlying physical mechanism reveals the role of statistical integrals of motion in nonequilibrium systems.
Abstract: The understanding of fluid turbulence has considerably progressed in recent years. The application of the methods of statistical mechanics to the description of the motion of fluid particles, i.e., to the Lagrangian dynamics, has led to a new quantitative theory of intermittency in turbulent transport. The first analytical description of anomalous scaling laws in turbulence has been obtained. The underlying physical mechanism reveals the role of statistical integrals of motion in nonequilibrium systems. For turbulent transport, the statistical conservation laws are hidden in the evolution of groups of fluid particles and arise from the competition between the expansion of a group and the change of its geometry. By breaking the scale-invariance symmetry, the statistically conserved quantities lead to the observed anomalous scaling of transported fields. Lagrangian methods also shed new light on some practical issues, such as mixing and turbulent magnetic dynamo.
1,186 citations
01 Jan 1992
TL;DR: In this article, cross-correlation methods of interrogation of successive single-exposure frames can be used to measure the separation of pairs of particle images between successive frames, which can be optimized in terms of spatial resolution, detection rate, accuracy and reliability.
Abstract: To improve the performance of particle image velocimetry in measuring instantaneous velocity fields, direct cross-correlation of image fields can be used in place of auto-correlation methods of interrogation of double- or multiple-exposure recordings. With improved speed of photographic recording and increased resolution of video array detectors, cross-correlation methods of interrogation of successive single-exposure frames can be used to measure the separation of pairs of particle images between successive frames. By knowing the extent of image shifting used in a multiple-exposure and by a priori knowledge of the mean flow-field, the cross-correlation of different sized interrogation spots with known separation can be optimized in terms of spatial resolution, detection rate, accuracy and reliability.
1,101 citations
TL;DR: In this paper, the authors proposed a monotone integrated large eddy simulation approach, which incorporates a form of turbulence modeling applicable when the large-scale flows of interest are intrinsically time dependent, thus throwing common statistical models into question.
864 citations