Download or read book Liner Impedance Modeling in the Time Domain with Flow written by Christoph Richter and published by Univerlagtuberlin. This book was released on 2009 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time Domain Impedance Modeling of Perforate Liners Including the Effects of Bias and Grazing Flows written by John William Premo and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Nacelle Acoustic Lining Concepts Development written by and published by . This book was released on 2002 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2008 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermoacoustic Combustion Instability Control written by Dan Zhao and published by Academic Press. This book was released on 2023-02-13 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoacoustic Combustion Instability Control: Engineering Applications and Computer Codes provides a unique opportunity for researchers, students and engineers to access recent developments from technical, theoretical and engineering perspectives. The book is a compendium of the most recent advances in theoretical and computational modeling and the thermoacoustic instability phenomena associated with multi-dimensional computing methods and recent developments in signal-processing techniques. These include, but are not restricted to a real-time observer, proper orthogonal decomposition (POD), dynamic mode decomposition, Galerkin expansion, empirical mode decomposition, the Lattice Boltzmann method, and associated numerical and analytical approaches. The fundamental physics of thermoacoustic instability occurs in both macro- and micro-scale combustors. Practical methods for alleviating common problems are presented in the book with an analytical approach to arm readers with the tools they need to apply in their own industrial or research setting. Readers will benefit from practicing the worked examples and the training provided on computer coding for combustion technology to achieve useful results and simulations that advance their knowledge and research. Focuses on applications of theoretical and numerical modes with computer codes relevant to combustion technology Includes the most recent modeling and analytical developments motivated by empirical experimental observations in a highly visual way Provides self-contained chapters that include a comprehensive, introductory section that ensures any readers new to this topic are equipped with required technical terms

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Aerodynamics Aeroacoustics and Aeroelasticity of Turbomachines written by Kenneth C. Hall and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is a collection of technical papers that were presented at the 10th International Symposium on Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines held September 8-11, 2003 at Duke University in Durham, North Carolina. The papers represent the latest in state of the art research in the areas of aeroacoustics, aerothermodynamics, computational methods, experimental testing related to flow instabilities, flutter, forced response, multistage, and rotor-stator effects for turbomachinery.

Download or read book European Success Stories in Industrial Mathematics written by Thibaut Lery and published by Springer Science & Business Media. This book was released on 2011-09-15 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book presents real world success stories of collaboration between mathematicians and industrial partners, showcasing first-hand case studies, and lessons learned from the experiences, technologies, and business challenges that led to the successful development of industrial solutions based on mathematics. It shows the crucial contribution of mathematics to innovation and to the industrial creation of value, and the key position of mathematics in the handling of complex systems, amplifying innovation. Each story describes the challenge that led to the industrial cooperation, how the challenge was approached and how the solutions were achieved and implemented. When brought together, they illustrate the versatile European landscape of projects in almost all areas of applied mathematics and across all business sectors. This book of success stories has its origin in the Forward Look about Mathematics and Industry that was funded by the European Science Foundation (ESF) and coordinated by the Applied Mathematics Committee of the European Mathematical Society (EMS). In each of these success stories, researchers, students, entrepreneurs, policy makers and business leaders in a range of disciplines will find valuable material and important lessons that can be applied in their own fields.​

Download or read book Healthy and energy efficient buildings written by Sunil K. Sansaniwal and published by Frontiers Media SA. This book was released on 2023-12-21 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Research Topic on 'Healthy and Energy Efficient Buildings' focuses on the emerging need for sustainable and healthy indoor environments. The built environment contributes significantly to energy consumption and environmental degradation, leading to adverse effects on human health and well-being. Therefore, this Research Topic aims to bring together cutting-edge research that addresses the complex interplay between building energy efficiency and occupant health. The scope of the Research Topic covers topics such as energy efficiency, indoor environmental quality, sustainable energy, health and well-being, building codes and standards, energy management and green building practices. The ultimate goal of the Research Topic is to promote sustainable building practices and enhance the well-being of building occupants while reducing the environmental impact of buildings. While energy efficiency has become a top priority in building design, there has been less emphasis on creating indoor environments that are conducive to good health. To achieve the goal of this Research Topic, recent advances in building design, construction, and operation must be incorporated. These include the use of advanced materials and technologies, such as smart sensors and automation systems that can monitor and control indoor air quality, temperature, and lighting levels to create optimal indoor conditions for occupants. Additionally, the integration of renewable energy sources, such as solar and wind power, can help reduce the carbon footprint of buildings. In order to promote healthy buildings, there is a need for more research on the impact of building design and materials on indoor air quality and occupant health. This includes exploring the use of natural ventilation and passive cooling strategies, as well as the use of low-emitting materials and finishes that do not off-gas harmful chemicals. This Research Topic seeks to address the need for sustainable buildings that prioritize both energy efficiency and occupant health.

Download or read book Acoustic Treatment Design Scaling Methods written by R. E. Kraft and published by . This book was released on 1999 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances In Computation Modeling And Control Of Transitional And Turbulent Flows written by Tapan K Sengupta and published by World Scientific. This book was released on 2015-12-01 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of high performance computing in current research on transitional and turbulent flows is undoubtedly very important. This review volume provides a good platform for leading experts and researchers in various fields of fluid mechanics dealing with transitional and turbulent flows to synergistically exchange ideas and present the state of the art in the fields.Contributed by eminent researchers, the book chapters feature keynote lectures, panel discussions and the best invited contributed papers.

Download or read book Acoustic Treatment Design Scaling Methods written by and published by . This book was released on 1999 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Journal of the Acoustical Society of America written by Acoustical Society of America and published by . This book was released on 2006 with total page 1052 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerospace America written by and published by . This book was released on 2006 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Aeroacoustics with Applications to Aeropropulsion Systems written by Xiaofeng Sun and published by Elsevier. This book was released on 2020-10-14 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Aeroacoustics with Applications to Aeropropulsion Systems from the Shanghai Jiao Tong University Press Aerospace series, is the go-to reference on the topic, providing a modern take on the fundamental theory and applications relating to prediction and control of all major noise sources in aeropropulsion systems. This important reference compiles the latest knowledge and research advances, considering both the physics of aerodynamic noise generation in aero-engines and related numerical prediction techniques. Additionally, it introduces new vortex sound interaction models, a transfer element method, and a combustion instability model developed by the authors. Focusing on propulsion systems from inlet to exit, including combustion noise, this new resource will aid graduate students, researchers, and R&D engineers in solving the aircraft noise problems that currently challenge the industry. Updates the knowledge-base on the sound source generated by aeropropulsion systems, from inlet to exit, including combustion noise Covers new aerodynamic noise control technology aimed at the low-noise design of next generation aero-engines, including topics such as aerodynamic noise and aero-engine noise control Includes new, cutting-edge models and methods developed by an author team led by the editor-in-chief of the Chinese Journal of Aeronautics and Astronautics Considers both the physics of aerodynamic noise generation in aero-engines and related numerical prediction techniques

Download or read book Acoustic Treatment Design Scaling Methods Volume 4 Numerical Simulation of the Nonlinear Acoustic Impedance of a Perforated Plate Single Degree Of Freedom Resonator Using a Time Domain Finite Difference Method written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-29 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-degree-of-freedom resonators consisting of honeycomb cells covered by perforated facesheets are widely used as acoustic noise suppression liners in aircraft engine ducts. The acoustic resistance and mass reactance of such liners are known to vary with the intensity of the sound incident upon the panel. Since the pressure drop across a perforated liner facesheet increases quadratically with the flow velocity through the facesheet, this is known as the nonlinear resistance effect. In the past, two different empirical frequency domain models have been used to predict the Sound Pressure Level effect of the incident wave on the perforated liner impedance, one that uses the incident particle velocity in isolated narrowbands, and one that models the particle velocity as the overall velocity. In the absence of grazing flow, neither frequency domain model is entirely accurate in predicting the nonlinear effect that is measured for typical perforated sheets. The time domain model is developed in an attempt to understand and improve the model for the effect of spectral shape and amplitude of multi-frequency incident sound pressure on the liner impedance. A computer code for the time-domain finite difference model is developed and predictions using the models are compared to current frequency-domain models.Kraft, R. E.Glenn Research Center; Langley Research CenterDEGREES OF FREEDOM; NOISE REDUCTION; PRESSURE EFFECTS; SOUND INTENSITY; HONEYCOMB STRUCTURES; AIRCRAFT ENGINES; GRAZING FLOW; NOISE (SOUND); FLOW VELOCITY; MATHEMATICAL MODELS; RESONATORS; SOUND PRESSURE; NONLINEARITY

Download or read book Analysis and Discretization of Time Domain Impedance Boundary Conditions in Aeroacoustics written by Florian Monteghetti and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In computational aeroacoustics, time-domain impedance boundary conditions (TDIBCs) canbe employed to model a locally reacting sound absorbing material. They enable to computethe effect of a material on the sound field after a homogenization distance and have proveneffective in noise level predictions. The broad objective of this work is to study the physical,mathematical, and computational aspects of TDIBCs, starting from the physical literature.The first part of this dissertation defines admissibility conditions for nonlinear TDIBCs underthe impedance, admittance, and scattering formulations. It then shows that linear physicalmodels, whose Laplace transforms are irrational, admit in the time domain a time-delayedoscillatory-diffusive representation and gives its physical interpretation. This analysis enablesto derive the discrete TDIBC best suited to a particular physical model, by contrast with a onesize-fits-all approach, and suggests elementary ways of computing the poles and weights. Theproposed time-local formulation consists in composing a set of ordinary differential equationswith a transport equation.The main contribution of the second part is the proof of the asymptotic stability of the multidimensionalwave equation coupled with various classes of admissible TDIBCs, whose Laplacetransforms are positive-real functions. The method of proof consists in formulating an abstractCauchy problem on an extended state space using a realization of the impedance, be it finiteor infinite-dimensional. The asymptotic stability of the corresponding strongly continuoussemigroup of contractions is then obtained by verifying the sufficient spectral conditions of theArendt-Batty-Lyubich-V ̃u theorem.The third and last part of the dissertation tackles the discretization of the linearized Eulerequations with TDIBCs. It demonstrates the computational advantage of using the scatteringoperator over the impedance and admittance operators, even for nonlinear TDIBCs. This isachieved by a systematic semi-discrete energy analysis of the weak enforcement of a genericnonlinear TDIBC in a discontinuous Galerkin finite element method. In particular, the analysishighlights that the sole definition of a discrete model is not enough to fully define a TDIBC.To support the analysis, an elementary physical nonlinear scattering operator is derived andits computational properties are investigated in an impedance tube. Then, the derivation oftime-delayed broadband TDIBCs from physical reflection coefficient models is carried out forsingle degree of freedom acoustical liners. A high-order discretization of the derived time-localformulation, which consists in composing a set of ordinary differential equations with a transportequation, is applied to two flow ducts.