Download or read book Computational Modeling of MEMS Microjets for Turbulent Boundary Layer Control written by and published by . This book was released on 2004 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a three year continuation of our earlier AFOSR work, we examine novel MEMS actuators for turbulent boundary layer control. The devices of interest are small and closely spaced and hence require detailed direct numerical simulation of the near surface flow to capture the physics. The devices we examine in most detail are arrays of discrete wall-normal jets to test a practical implementation of the opposition control schemes already shown to produce large drag reductions. We also performed some simple experiments examining pairs of small suction holes used to generate hairpin vortices. While the actuators are examined for their potential application for drag reduction, the emphasis of the work is more on studying the fundamental nature of the flows generated by such devices and how such small scale flows interact with the turbulent vortex structures in a wall-bounded flow. In this final report we emphasize results from simulations of arrays of 3-D slot-jet actuators triggered by practical wall-mounted sensors. Time averaged data show how the jet arrays affect the mean shear stress distribution over the controlled surface while instantaneous data show the interactions of the three-dimensional structures in detail.
Download or read book A Computational Investigation of MEMS written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We applied a recently developed direct numerical simulation approach to examine MEMS for turbulent boundary layer control. We have carried out simulations of synthetic jets and textured surfaces in this first phase of the study and, in the present one-year follow-on work, are modeling concepts involving hybrid active/passive elements. We have completed a flow and geometric parameter study of synthetic jets and have produced valuable insight into the detailed physics of the actuators. In this final report we present results from simulations of periodic arrays of 2-D and 3-D pulsed synthetic jets into an initially quiescent flow, simulations of slot jets actuating beneath a turbulent boundary layer, studies on the behavior of hairpin vortices and, separately, preliminary simulations of turbulent flow over arrays of chevrons.
Download or read book Direct Numerical Simulation of Microjets for Turbulent Boundary Layer Control written by Conrad Yuan Yuen Lee and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Continued Computational Investigation of MEMS written by David B. Goldstein and published by . This book was released on 2003 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of MEMS Suction and Blowing for Turbulent Boundary Layer Control written by Conrad Y. Lee and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DNS of Microjets for Turbulent Boundary Layer Control written by Conrad Y. Lee and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book IUTAM Symposium on Flow Control and MEMS written by Jonathan F. Morrison and published by Springer Science & Business Media. This book was released on 2008 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Symposium brought together many of the world’s experts in fluid mechanics, microfabrication and control theory to discover the synergy that can lead to real advances and perhaps find ways in which collaborative projects may proceed. The high profile meeting was attended by keynote speakers who are leaders in their fields. A key driver was the improvement in flow efficiency to reduce drag, and thereby emissions arising from transport. About 65 papers were presented.
Download or read book Lindstr miana written by and published by . This book was released on 1959 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Lattice Boltzmann Simulations of Micro Blowing Strategies for Subsonic and Supersonic Drag Control written by and published by . This book was released on 2003 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frontiers in Computational Fluid Structure Interaction and Flow Simulation written by Tayfun E. Tezduyar and published by Springer. This book was released on 2018-10-26 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational fluid-structure interaction and flow simulation are challenging research areas that bring solution and analysis to many classes of problems in science, engineering, and technology. Young investigators under the age of 40 are conducting much of the frontier research in these areas, some of which is highlighted in this book. The first author of each chapter took the lead role in carrying out the research presented. The topics covered include Computational aerodynamic and FSI analysis of wind turbines, Simulating free-surface FSI and fatigue-damage in wind-turbine structural systems, Aorta flow analysis and heart valve flow and structure analysis, Interaction of multiphase fluids and solid structures, Computational analysis of tire aerodynamics with actual geometry and road contact, and A general-purpose NURBS mesh generation method for complex geometries. This book will be a valuable resource for early-career researchers and students — not only those interested in computational fluid-structure interaction and flow simulation, but also other fields of engineering and science, including fluid mechanics, solid mechanics and computational mathematics – as it will provide them with inspiration and guidance for conducting their own successful research. It will also be of interest to senior researchers looking to learn more about successful research led by those under 40 and possibly offer collaboration to these researchers.
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2005 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distributed Turbulent Flow Control by MEMS Integrated With Neural Networks written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed new fabrication techniques that can allow the formerly incompatible CMOS and MEMS devices to be integrated onto a single chip. This achievement leads to the M3 system, which consists of monolithically integrated sensor-logics-actuator. The M3 system can be used to control the wall streaks in a turbulent boundary. Experimentation work revealed and solved many of the problems associated with having electronic devices work in close proximity with each other and is progressing on the efforts to develop a control system using a neural network logic. Implementation of the network as well as a more general, fully adaptive neural network onto electronic circuitry has been accomplished. Finally, CFD studies have been performed which reveals and explains the mechanisms at work in the interaction between an oscillating flap and the turbulent boundary layer.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Multiphysics Simulation and Experimental Testing of Mems written by Attilio Frangi and published by Imperial College Press. This book was released on 2008 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume takes a much needed multiphysical approach to the numerical and experimental evaluation of the mechanical properties of MEMS and NEMS. The contributed chapters present many of the most recent developments in fields ranging from microfluids and damping to structural analysis, topology optimization and nanoscale simulations. The book responds to a growing need emerging in academia and industry to merge different areas of expertise towards a unified design and analysis of MEMS and NEMS.
Download or read book Machine Learning Control Taming Nonlinear Dynamics and Turbulence written by Thomas Duriez and published by Springer. This book was released on 2016-11-02 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first textbook on a generally applicable control strategy for turbulence and other complex nonlinear systems. The approach of the book employs powerful methods of machine learning for optimal nonlinear control laws. This machine learning control (MLC) is motivated and detailed in Chapters 1 and 2. In Chapter 3, methods of linear control theory are reviewed. In Chapter 4, MLC is shown to reproduce known optimal control laws for linear dynamics (LQR, LQG). In Chapter 5, MLC detects and exploits a strongly nonlinear actuation mechanism of a low-dimensional dynamical system when linear control methods are shown to fail. Experimental control demonstrations from a laminar shear-layer to turbulent boundary-layers are reviewed in Chapter 6, followed by general good practices for experiments in Chapter 7. The book concludes with an outlook on the vast future applications of MLC in Chapter 8. Matlab codes are provided for easy reproducibility of the presented results. The book includes interviews with leading researchers in turbulence control (S. Bagheri, B. Batten, M. Glauser, D. Williams) and machine learning (M. Schoenauer) for a broader perspective. All chapters have exercises and supplemental videos will be available through YouTube.
Download or read book Compressibility Turbulence and High Speed Flow written by Thomas B. Gatski and published by Academic Press. This book was released on 2013-03-05 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and an extensive discussion of the various approaches used in predicting both free shear and wall bounded flows is presented. Experimental measurement techniques common to the compressible flow regime are introduced with particular emphasis on the unique challenges presented by high speed flows. Both experimental and numerical simulation work is supplied throughout to provide the reader with an overall perspective of current trends. An introduction to current techniques in compressible turbulent flow analysis An approach that enables engineers to identify and solve complex compressible flow challenges Prediction methodologies, including the Reynolds-averaged Navier Stokes (RANS) method, scale filtered methods and direct numerical simulation (DNS) Current strategies focusing on compressible flow control
Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.
