A Non-gaussian Turbulence Simulation

A Non-gaussian Turbulence Simulation PDF Author: Paul M. Reeves
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 80

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Book Description
A comparison of the statistical properties of low altitude atmospheric turbulence and the characteristics of presently used simulation techniques shows that these techniques do not satisfactorily account for the non-Gaussian nature of turbulence. A non-Gaussian turbulence simulation, intended to be used in conjunction with piloted flight simulators, is developed. The simulation produces three simultaneous random processes which represent the three orthogonal gust components. The probability distribution of each component is characterized by a modified Bessel function. The rms intensity and scale length of each component are independent parameters. A general method of introducing cross spectra between components is demonstrated. The multiplication of independent random processes is used to generate each of the gust components. Gaussian white noise generators, analog multipliers, and linear filters are used throughout the simulation. A complete analog circuit diagram is presented. (Author).

A Non-gaussian Turbulence Simulation

A Non-gaussian Turbulence Simulation PDF Author: Paul M. Reeves
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 80

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Book Description
A comparison of the statistical properties of low altitude atmospheric turbulence and the characteristics of presently used simulation techniques shows that these techniques do not satisfactorily account for the non-Gaussian nature of turbulence. A non-Gaussian turbulence simulation, intended to be used in conjunction with piloted flight simulators, is developed. The simulation produces three simultaneous random processes which represent the three orthogonal gust components. The probability distribution of each component is characterized by a modified Bessel function. The rms intensity and scale length of each component are independent parameters. A general method of introducing cross spectra between components is demonstrated. The multiplication of independent random processes is used to generate each of the gust components. Gaussian white noise generators, analog multipliers, and linear filters are used throughout the simulation. A complete analog circuit diagram is presented. (Author).

NASA Technical Paper

NASA Technical Paper PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 34

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Book Description


Interstellar Turbulence

Interstellar Turbulence PDF Author: José Franco
Publisher: Cambridge University Press
ISBN: 9780521651318
Category : Science
Languages : en
Pages : 304

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Book Description
This timely volume presents a series of review articles covering every aspect of interstellar turbulence--from accretion disks, molecular clouds, atomic and ionized media, through to spiral galaxies - based on a major international conference held in Mexico City.With advances in observational techniques and the development of more efficient computer codes and faster computers, research in this area has made spectacular progress in recent years. This book provides a comprehensive overview of the most important developments in observing and modelling turbulent flows in the cosmos. It provides graduate student and researchers with a state-of-the-art summary of observational, theoretical and computational research in interstellar turbulence.

Piloted Aircraft Environment Simulation Techniques

Piloted Aircraft Environment Simulation Techniques PDF Author: North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Flight Mechanics Panel
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 334

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Book Description


NASA Technical Memorandum

NASA Technical Memorandum PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 560

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Book Description


Advances and Challenges in Space-time Modelling of Natural Events

Advances and Challenges in Space-time Modelling of Natural Events PDF Author: Emilio Porcu
Publisher: Springer Science & Business Media
ISBN: 3642170862
Category : Mathematics
Languages : en
Pages : 263

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Book Description
This book arises as the natural continuation of the International Spring School "Advances and Challenges in Space-Time modelling of Natural Events," which took place in Toledo (Spain) in March 2010. This Spring School above all focused on young researchers (Master students, PhD students and post-doctoral researchers) in academics, extra-university research and the industry who are interested in learning about recent developments, new methods and applications in spatial statistics and related areas, and in exchanging ideas and findings with colleagues.

Modelling of Pollutants in Complex Environmental Systems

Modelling of Pollutants in Complex Environmental Systems PDF Author: Grady Hanrahan
Publisher: ILM Publications
ISBN: 1906799016
Category : Nature
Languages : en
Pages : 489

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Book Description
Environmental modelling has enjoyed a long tradition, but there is a defined need to continually address both the power and the limitations of such models, as well as their quantitative assessment. This book showcases modern environmental modelling methods, the basic theory behind them and their incorporation into complex environmental investigations. It highlights advanced computing technologies and how they have led to unprecedented and adaptive modelling, simulation and decision-support tools to study complex environmental systems, and how they can be applied to current environmental concerns. This volume is essential reading for researchers in academia, industry and government-related bodies who have a vested interest in all aspects of environmental modelling. Features include: A range of modern environmental modelling techniques are described by experts from around the world, including the USA, Canada, Australia, Europe and Thailand; many examples from air, water, soil/sediment and biological matrices are covered in detail throughout the book; key chapters are included on modelling uncertainty and sensitivity analysis; and, a selection of figures are provided in full colour to enable greater comprehension of the topics discussed.

Physical Processes in Clouds and Cloud Modeling

Physical Processes in Clouds and Cloud Modeling PDF Author: Alexander P. Khain
Publisher: Cambridge University Press
ISBN: 1108651550
Category : Science
Languages : en
Pages : 643

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Book Description
This book presents the most comprehensive and systematic description currently available of both classical and novel theories of cloud processes, providing a much-needed link between cloud theory, observation, experimental results, and cloud modeling. This volume shows why and how modern models serve as a major tool of investigation of cloud processes responsible for atmospheric phenomena, including climate change. It systematically describes classical as well as recent advancements in cloud physics, including cloud-aerosol interaction; collisions of particles in turbulent clouds; and the formation of multiphase cloud particles. As the first of its kind to serve as a practical guide for using state-of-the-art numerical cloud models, major emphasis is placed on explaining how microphysical processes are treated in modern numerical cloud resolving models. The book will be a valuable resource for advanced students, researchers and numerical model designers in cloud physics, atmospheric science, meteorology, and environmental science.

Wind Energy for the Next Millennium

Wind Energy for the Next Millennium PDF Author: E. L. Petersen
Publisher: Earthscan
ISBN: 9781902916002
Category : Wind power
Languages : en
Pages : 1290

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Book Description
First Published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.

Turbulent Flows

Turbulent Flows PDF Author: Jean Piquet
Publisher: Springer Science & Business Media
ISBN: 3662035596
Category : Technology & Engineering
Languages : en
Pages : 767

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Book Description
obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.