Download or read book Turbulent Microfronts written by and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research work under this contract studied turbulence structures in the atmospheric boundary layer by focussing on microfronts. Microfronts are zones of sharp gradients which occur at the leading edge of wind gusts and upstream edges of thermals. The present work indicates that microfronts also result from convergence zones induced by horseshoe vortices and longitudinal roll vortices. The microfronts and their parent eddy structures account for the majority of the flux in the boundary layer, and in cases of strong winds, contribute to wind damage and structural fatique. However, existing methods, such as Fourier spectra, cannot be used to study microfronts which are local and aperiodic. In fact, microfronts and boundary layer eddies have been traditionally studied in terms of subjective conditional sampling. To avoid this subjectivity, we have developed objective techniques to study atmospheric turbulence from the microfront point of view. These include new methods for computing spectra and filtering data. The techniques developed in this work have then been used to study coherent structures and their transport in the atmospheric boundary layer.
Download or read book Research in Progress written by and published by . This book was released on 1992 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identifying Coherent Motions in Near Surface Turbulence written by Alex Anderson and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Near-surface turbulence is responsible for around 70% of the fluxes of heat, momentum, and mass between Earth's surface and its atmosphere and provides important boundary conditions for atmospheric dynamics. To improve the modeling of this turbulence and the fluxes it carries, it is important to understand the microscale coherent structures and associated microfronts of the turbulent motions. In the presence of mean shear, the turbulent mixing of air with different momentum causes horizontal convergence and combines with existing temperature stratification to create temperature microfronts in time series. In this work, temperature microfronts are identified using sonic anemometer data ranging from 10 to 29 meters above the surface during turbulent periods from the Canopy Horizontal Array Turbulence Study (CHATS) from March to June 2007. Each temperature microfront is characterized by a sharp temperature drop following a gradual temperature increase. Temperature and time scales derived from the temperature standard deviation and integral time scale are used to develop new identification criteria of temperature microfronts that are more data dependent and objective. The temperature time series is combined with an analysis of quiescent periods and the velocity components to identify the passage of individual temperature burst events. Using these criteria, 44 initial events were identified and categorized further into three categories. The new criteria are successful in refining microfront characteristics and automating the identification process to objectively extract individual burst events.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Cascades II written by Mikhael Gorokhovski and published by Springer. This book was released on 2019-05-21 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gathering contributions by the most prominent researchers in a highly specialised field, this proceedings volume clarifies selected aspects of the physics of turbulent cascades and their statistical universalities under complex stationary and non-homogeneous conditions. Here, these conditions are induced by the presence of a gas/liquid interface, inertial particles, strong shear, rotation, MHD and stratification. By proposing different ways to model turbulence effects under these complex conditions, the book will be of considerable interest not only to academic researchers, but also to specialists and junior researchers in the domain of propulsion and power, as well as those whose work involves various applications related to atmospheric, oceanic and planetary physics.
Download or read book The Turbulent Ocean written by S. A. Thorpe and published by Cambridge University Press. This book was released on 2005-10-27 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of ocean turbulence is in a state of discovery and development with many intellectual challenges. This book describes the principal dynamic processes that control the distribution of turbulence, its dissipation of kinetic energy and its effects on the dispersion of properties such as heat, salinity, and dissolved or suspended matter in the deep ocean, the shallow coastal and the continental shelf seas. It focuses on the measurement of turbulence, and the consequences of turbulent motion in the oceanic boundary layers at the sea surface and near the seabed. Processes are illustrated by examples of laboratory experiments and field observations. The Turbulent Ocean provides an excellent resource for senior undergraduate and graduate courses, as well as an introduction and general overview for researchers. It will be of interest to all those involved in the study of fluid motion, in particular geophysical fluid mechanics, meteorology and the dynamics of lakes.
Download or read book Turbulent Dissipation in Frontal Zones from Hot Wire Measurements in the MICROFRONTS Experiment written by and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of turbulent dissipation of kinetic energy have been taken of synoptic and small scale density frontal passages during the MICROFRONTS (MARCH 1999, Kansas) field program. It is revealed that there is a significant increase of turbulent kinetic energy during each-passage of the frontal transition zone. Data analyses suggest a linear relationship between the frontal width and the enhanced kinetic energy dissipation rate. A theoretical development supports this observational result. The conclusion is, however, tentative, because the data are limited and some physical processes have not been taken into account. The source of turbulence associated with a shallow density front and trailing current is also analyzed. The characteristics of dissipation in this small scale event, and the heat budget associated with the front and current are determined. Other analyses carried out as part of the front-boundary layer focus of this investigation, include the investigation of the turbulence and heat budget characteristics of the lowest 10 meters of the atmosphere as a function of static stability, and the characteristics of frontogenesis in the presence of inertial oscillations. The various results obtained are all related to the development of parameterization schemes that are required by weather prediction models.
Download or read book Near wall Turbulent Flows written by Ronald M. C. So and published by Elsevier Publishing Company. This book was released on 1993 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of near-wall turbulence from experimental, theoretical and numerical sources is accumulating at an ever increasing rate. An overview of the latest important developments is reported and discussed in depth in this volume with the goal of stimulating closer dialogue between researchers in all areas of near-wall turbulence. The full text of 95 contributed papers cover a broad range of topics in near-wall turbulent flows that includes boundary layers, coherent structures, drag reduction, experimental methods, high speed flows, numerical simulations, transition and turbulent modeling. The innovativeness of the contributions demonstrates that near-wall turbulence remains a vital and dynamically evolving field with important technological consequences for the future.
Download or read book Effects of Canopy Micrometeorology on the Turbulent Transport Processes Above and Within an Urban Forest written by Frank Joseph Marsik and published by . This book was released on 1995 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Characteristics of Coherent Turbulent Structures and Exchange Processes in the Atmospheric Surface Layer Within and Above an Orchard Canopy written by Changan Zhang and published by . This book was released on 1991 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Simulation of Turbulent Flow Across a Forest Edge written by Bai Yang and published by . This book was released on 2003 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precipitation Scavenging And Atmosphere Surface Exchange written by Stephen Schwartz and published by CRC Press. This book was released on 1992-06-01 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This three-volume set contains selected papers arising from a conference held in 1991 on precipitation and air pollution. The first volume addresses the precipitation scavenging process; the second deals with atmosphere-surface exchange processes; and the third covers air pollution and deposition.
Download or read book Curricula in the Atmospheric Oceanic Hydrologic and Related Sciences written by and published by . This book was released on 1992 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ris National Laboratory Meteorology and Wind Energy Department written by E. L. Petersen and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large eddy Simulation of Turbulent Flow Above and Within a Plant Canopy written by Edward Garrett Patton and published by . This book was released on 1997 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing of Turbulence written by Victor Raizer and published by CRC Press. This book was released on 2021-10-04 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a unique multidisciplinary integration of the physics of turbulence and remote sensing technology. Remote Sensing of Turbulence provides a new vision on the research of turbulence and summarizes the current and future challenges of monitoring turbulence remotely. The book emphasizes sophisticated geophysical applications, detection, and recognition of complex turbulent flows in oceans and the atmosphere. Through several techniques based on microwave and optical/IR observations, the text explores the technological capabilities and tools for the detection of turbulence, their signatures, and variability. FEATURES Covers the fundamental aspects of turbulence problems with a broad geophysical scope for a wide audience of readers Provides a complete description of remote-sensing capabilities for observing turbulence in the earth’s environment Establishes the state-of-the-art remote-sensing techniques and methods of data analysis for turbulence detection Investigates and evaluates turbulence detection signatures, their properties, and variability Provides cutting-edge remote-sensing applications for space-based monitoring and forecasts of turbulence in oceans and the atmosphere This book is a great resource for applied physicists, the professional remote sensing community, ecologists, geophysicists, and earth scientists.
Download or read book An Experimental Investigation of the Evolution of Turbulent Potential and Kinetic Energies and the Vertical Temperature Structure of Homogeneous Stably Stratified Sheared Turbulence written by Kurt Harting Keller and published by . This book was released on 1999 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
