The relationships of ranges to their respective standard deviations for wind direction and speed fluctuations are found for two urban locations at a height of 33 f t . above ground level. The standard deviations are computed from 1-, 5-, lo-, and 15-sec. average and 5-, lo-, and 15-sec. iiistantaiieous chart readings. The sampling intervals for which the standard deviations and ranges are compu...

A novel shrouded wind-solar hybrid renewable energy and rain water harvester with an omni-directional-guide-vane (ODGV) for urban high-rise application is introduced. The ODGV surrounds the vertical axis wind turbine (VAWT) and enhances the VAWT performance by increasing the on-coming wind speed and guiding it to an optimum flow angle before it interacts with the rotor blades. An ODGV scaled mo...

Gravity ventilators rely simply on air buoyancy to extract air and are widely used to exhaust air contaminants and heat from workplaces using minimal energy. They are designed to maximize the exhaust flow rate, but the rain penetration sometimes causes malfunctioning. In this study, the characteristics of rain penetration through a ventilator were examined as a preliminary study to develop a ve...

Roughness length is a critical parameter for estimation of wind conditions, and it is therefore also relevant for the estimation of human thermal conditions in urban areas. The high density of buildings in urban areas causes large changes in land coverage, thereby increasing surface roughness. This influence atmospheric flow and also leads to a reduction in urban air ventilation, thus increasin...

the main objective of a research program, whose output is presented here, has been to estimate “ventilation coefficients”, a critical parameter in determining air pollution concentration near the surface ground which signifies the ability for natural ventilation of an air shed in an urban or rural area. relevant measured data from the city of tehran has been used to calibrate and further de...

In comparison with atmospheric boundary-layer winds, which are customarily treated as stationary, gust-front winds such as a thunderstorm/downburst exhibit strong nonstationarity. In storms characterized by a gust-front, wind speed changes rapidly during a short time period. In order to realistically describe attendant loads effects, a new analysis framework is presented which is named the gust...

A model of surface waves generated on deep water by strong winds is proposed. A two-layer approximation is adopted, in which a shallow turbulent layer overlies the lower, infinitely deep layer. The dynamics of the upper layer, which is directly exposed to the wind, are nonlinear and coupled to the linear dynamics in the deep fluid. The authors demonstrate that in such a system there exist stead...