Download or read book An Estimation of Turbulent Kinetic Energy and Energy Dissipation Rate Based on Atmospheric Boundary Layer Similarity Theory 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 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Algorithms are developed to extract atmospheric boundary layer profiles for turbulence kinetic energy (TKE) and energy dissipation rate (EDR), with data from a meteorological tower as input. The profiles are based on similarity theory and scalings for the atmospheric boundary layer. The calculated profiles of EDR and TKE are required to match the observed values at 5 and 40 m. The algorithms are coded for operational use and yield plausible profiles over the diurnal variation of the atmospheric boundary layer.Han, Jongil and Arya, S. Pal and Shaohua, Shen and Lin, Yuh-Lang and Proctor, Fred H. (Technical Monitor)Langley Research CenterTURBULENCE; KINETIC ENERGY; ENERGY DISSIPATION; TURBULENT BOUNDARY LAYER; ATMOSPHERIC BOUNDARY LAYER; METEOROLOGICAL INSTRUMENTS; ALGORITHMS; DIURNAL VARIATIONS
Download or read book An Estimation of Turbulent Kinetic Energy and Energy Dissipation Rate Based on Atmospheric Boundary Layer Similarity Theory written by and published by . This book was released on 2000 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Kinetic Energy Budgets and Dissipation Rates in Disturbed Stable Boundary Layers written by J. K. Lundquist and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important parameter in the numerical simulation of atmospheric boundary layers is the dissipation length scale, l{sub {var_epsilon}}. It is especially important in weakly to moderately stable conditions, in which a tenuous balance between shear production of turbulence, buoyant destruction of turbulence, and turbulent dissipation is maintained. In large-scale models, the dissipation rate is often parameterized using a diagnostic equation based on the production of turbulent kinetic energy (TKE) and an estimate of the dissipation length scale. Proper parameterization of the dissipation length scale from experimental data requires accurate estimation of the rate of dissipation of TKE from experimental data. Using data from the MICROFRONTS and CASES-99 field programs, we evaluate turbulent kinetic energy (TKE), TKE dissipation rate {var_epsilon}, and dissipation length l{sub {var_epsilon}} over a range of stability regimes represented by a stable boundary layer (SBL), a destabilizing intrusion (by first a cold front and second a density current) and recovery. These data may be utilized to test recent parameterizations of dissipation rate {var_epsilon} and l{sub {var_epsilon}} in order to determine the suitability of these models for inclusion in mesoscale models for numerical weather prediction or pollution dispersion prediction.
Download or read book Journal of the Indian Geophysical Union written by Indian Geophysical Union and published by . This book was released on 2007 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Langley Scientific and Technical Information Output 2000 written by and published by . This book was released on 2001 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2004-07 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preprocessing for Eddy Dissipation Rate and TKE Profile Generation written by and published by . This book was released on 2001 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Annual Loss Prevention Symposium written by and published by . This book was released on 2004 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wake Vortex Algorithm Scoring Results written by and published by . This book was released on 2002 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Operational Performance of Sensor Systems Used to Determine Atmospheric Boundary Layer Properties as Part of the NASA Aircraft Vortex Spacing System Project written by and published by . This book was released on 2001 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Description of Selected Algorithms and Implementation Details of a Concept Demonstration Aircraft VOrtex Spacing System AVOSS written by and published by . This book was released on 2001 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Stress Over the Ocean written by Ian S. F. Jones and published by Cambridge University Press. This book was released on 2001-09-24 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive 2001 volume for researchers and graduate students in oceanography, meteorology, fluid dynamics and coastal engineering.
Download or read book NWRA AVOSS Wake Vortex Prediction Algorithm written by and published by . This book was released on 2002 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Freestream Turbulence on Boundary Layer Loss Generation written by Kanika Gakhar and published by . This book was released on 2020 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes an analysis of the effect of freestream turbulence (FST) on turbulent boundary layer loss generation. A relation has been derived between a turbulence parameter, which characterizes the FST, and the increase in boundary layer dissipation coefficient. The relation gives guidelines for trade studies, for example between combustor turbulence properties and turbine performance in a typical gas turbine engine. Based on the FST length-scale, two regimes of FST influence have been defined, with consequent different functional dependencies between FST parameters and boundary layer dissipation coefficient. In one regime, characterized by self-similarity of mean velocity and turbulence production profiles, the dissipation coefficient is a function of local parameters, and can be determined using measurement data for effects of FST on skin-friction. In the second regime, the boundary layer deviates from equilibrium due to the lag between the rate of turbulence production and dissipation. For this latter case, a method has been developed to estimate the effect of FST on dissipation using a modified shear-lag model, based on the conservation of turbulent kinetic energy. This thesis shows that the increase in boundary layer loss due to local FST can be as high as 73%, and that non-equilibrium effects can result in an additional increase in boundary layer loss as high as 8%. Finally, the framework developed in this thesis has also been applied to an industry relevant situation, quantifying the effect of combustor turbulence on high pressure turbine (HPT) performance. Example trade studies show that increasing the size of dilution ports, increasing the length of the combustor, and rearranging or re-orienting the dilution jets in cross-flow in the combustor all can help decrease HPT profile loss generation, and potentially increase stage efficiency up to 0.5%.
Download or read book 38th Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 2000 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Atmospheric Boundary Layer written by J. R. Garratt and published by Cambridge University Press. This book was released on 1994-04-21 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive and lucid account of the science of the atmospheric boundary layer (ABL). There is an emphasis on the application of the ABL to numerical modelling of the climate. The book comprises nine chapters, several appendices (data tables, information sources, physical constants) and an extensive reference list. Chapter 1 serves as an introduction, with chapters 2 and 3 dealing with the development of mean and turbulence equations, and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modelling of the ABL is crucially dependent for its realism on the surface boundary conditions, and chapters 4 and 5 deal with aerodynamic and energy considerations, with attention to both dry and wet land surfaces and sea. The structure of the clear-sky, thermally stratified ABL is treated in chapter 6, including the convective and stable cases over homogeneous land, the marine ABL and the internal boundary layer at the coastline. Chapter 7 then extends the discussion to the cloudy ABL. This is seen as particularly relevant, since the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic are now identified as key players in the climate system. Finally, chapters 8 and 9 bring much of the book's material together in a discussion of appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate simulation.
Download or read book Journal of Atmospheric and Oceanic Technology written by and published by . This book was released on 2002 with total page 1182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
