Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 16 of 16 for “"Atmospheric flow"”.
-
An object-based analysis of cloud motion from sequences of METEOSAT satellite data
The need for wind and atmospheric dynamics data for weather modelling and forecasting is well founded. Current texture-based techniques for tracking clouds in sequences of satellite imagery are robust at generating global cloud motion winds, but their use as wind data makes many simplifying …
-
Thermally generated convection and precipitation over volcanoes: Numerical modelling of flow over Montserrat
Atmospheric flow over orography is a classic research area, while the atmospheric response to surface heating has become a focus more recently in the context of solar heating and forest fires. Here, for the first time, these forcing mechanisms are superposed to examine atmospheric flow over a …
-
Passive enhancement of air flow at pedestrian level in built environments
… low wind speed at the pedestrian level due to flow obstruction induced by buildings. Urban street canyons, the outdoor spaces formed between buildings, often have much lower wind speed than the atmospheric wind above the roof level. In tropical regions, wind plays an important role to improve …
-
Estabilidade atmosférica em projetos eólicos: estimativa bayesiana do comprimento de Monin Obukhov e simulação do escoamento atmosférico
… wind project development. Bayesian estimates of atmospheric parameters using only average wind speed measurements of a cup anemometer and CFD simulations coupled with thermal equations are used in order to define a more consistent WRG database without acquiring more data, investment or …
-
An investigation into the effects of complex topography on particle dry deposition
… accident. The interaction of landscape features, atmospheric flow and particle dry deposition has been investigated with this in mind. Wind tunnel studies have been used with computational fluid dynamics to predict the deposition rate relative to a flat landscape. Good quantitative agreement was …
-
Acid-base catalysts for polycondensation of acetaldehyde in flow
… of these materials is evaluated in a gas phase, atmospheric flow system with a packed bed microreactor designed to mimic process conditions in one step of the overall bio-oil upgrading scheme. The HTlc is activated through calcination at 500 °C followed by rehydration in decarbonated H₂O, …
-
Wobbly winds in an ice age : the mutual interaction between the great continental ice sheets and atmospheric stationary waves
… significant obstacles to the westerly flow of the atmosphere. As the atmospheric flow is forced to deviate around such topographic features, stationary waves-large scale standing patterns in the winds and temperatures-are established within the atmosphere. The largest of the ice sheets, …
-
Aerodynamics study of the flowfield at a shelterbelt
… than total wind-speed reduction in the whole flowfield. The purpose of this study is to formulate a Navier-Stokes based scheme to simulate the turbulent aerodynamic characteristics of a shelterbelt. Qualitative results from field observation of a living-tree shelterbelt under real atmospheric …
-
Identifying dynamical boundaries and phase space transport using Lagrangian coherent structures
… specifically problems of separation in flows that can vary in scale from the micro to the geophysical. The first problem which we study is of the nontrivial motion of inertial particles in a two-dimensional fluid flow. We use the method of FTLE to identify transport barriers that produce …
-
On the role of high frequency waves in ocean altimetry
… the surface waves, radar backscatter, the atmospheric flow, and turbulent fluxes within the marine boundary layer. This uncommon ensemble provides the means to address several specific altimeter-related topics. First, we examine and document the impact that non wind-driven gravity wave …
-
Investigation of a gravity wave ducting event in the upper mesosphere
Atmospheric gravity waves (GWs) play an important role in the transport of energy and momentum throughout the Earth’s atmosphere. GW effects couple the lower regions of the atmosphere with the middle and upper regions of the atmosphere and the neutral atmosphere with the ionosphere. The effects are …
-
The transport of pollutants over South Africa and atmospheric sulphur in Cape Town
… study. The models were applied to simulate the atmospheric flow and chemistry transport over South Africa for two years (2001 and 2002), and the results were validated with observations within Cape Town. The models reproduced observed seasonal variability in atmospheric wind flow and sulphur …
-
The effect of dynamic operation and incoming flow on the wake of a utility-scale wind turbine
… is required. However, modeling wind turbine flows in the laboratory or in simulations is hindered by the wide range of relevant scales and the complexity of atmospheric flow and turbine operation. Because of these limitations, field scale studies are essential. Conventional field scale flow …
-
The role of wind and water in shaping earth's plateaus
… barriers to rainfall and to force changes in atmospheric flow. The thesis examines the complex topics of tectonic and climatic forcing of the surface-process regime on three different spatial and temporal scales: (1) bedrock wind-erosion rates are quantified in the arid Qaidam Basin of NW …
-
Climate Change and the Sea Breeze in the North Carolina Coast
… occur during offshore (53%) or parallel (22%) flow. However, as is the case throughout the literature, the maximization of SB fronts during offshore synoptic flow is sensitive to the synoptic wind speed. SB events that occurred under offshore synoptic-scale flow in the 0 to 4-6 m/s range were …
-
Caracterización numérica de la turbulencia en el estela de una aeroturbina mediante un modelo de simulación de grandes escalas
… three−dimensional and unsteady solution of fluid flow resolving turbulence physically except the smallest scales, which are modelled. The current models use a RANS closure method based in a Reynolds average over all scales of turbulence, so they provide information only about the average value of …