Papers by Keyword: Wind Velocity

Abstract: This work focuses on the pollutant dispersion problem with particular reference to thermal power plants. A powerful mathematical modeling to predict gaseous pollutant concentration at atmosphere and different CFD simulations results by Ansys CFX^® software are presented. The gaseous pollutant dispersion was evaluated by analyzing of different process parameters as wind velocity, gas emission rate and temperature. The study confirms wind velocity as main variable that strongly affecting dispersion phenomena.

Abstract: A wind turbine performs the function of converting the energy (kinetic) derived from the wind into another form of energy (mechanical) which is employed for the purpose of driving the generator which in turn generates electricity from this mechanical energy. The most common types of windmills employed in practice include horizontal and vertical axis wind mill. These windmills are fabricated in different structures for producing electricity. The main objective of this paper is to design an innovative eco friendly windmill to overcome the various difficulties existing in conventional windmills. In conventional windmills, the propeller rotation depends on the velocity of wind flow in the environment. But in this paper, we have fabricated an innovative eco friendly windmill in which, the propeller rotation is increased four times for the wind velocity in the surroundings.

Abstract: For studied the rule of wind turbine output characteristic in condition of variable wind. The paper set up a wind model for a wind farm and a simulation model of 1.5MW wind turbine. Choose two control tactics which called voltage control and reactive power control to do the simulation and test. The result shows that took reactive power control at normal operation, the turbine get a well performance. If fault happened, choose voltage control was reasonable. So it provide reference for turbine operation.

Abstract: In the present paper is analyzed the stress level and the maximum displacements that occur in the elements of a mast of 500 kN maximum hook load under the action of wind with a 70 km/h velocity. The mast is a prototype which is equipping a workover rig used for interventions and overhauling works for oil and gas wells. The forces resulting from wind pressure on the exposed mast`s elements areas are calculated in accordance with the oilfield industry standards and distributed to all structure`s nodes, after it was modeled using the FEA software ANSYS. Being a new structure containing structural steel rectangular pipes and profiles as L, I, U-shaped cross section, this analysis is necessary in order to achieve the practical construction of mast and its safety during exploitation.

Abstract: Emission of coal dusts can cause serious air pollution in coal-pile storage yard, which poses a threat to human health. Therefore, the quantitative research on particulate emissions is the premise for dealing with atmospheric pollution. In this paper, a series of experiments are firstly carried out in wind tunnel to study the impact of the wind velocity and water content on coal dusts for the mixing pile. Moreover, particle entrainment is investigated by measuring the velocity required to pick up particles from rest, also known as threshold velocity. Then a number of experimental data are obtained and a fitting formula is derived with the aid of Matlab. Finally, the results are compared with those published previously, and explanations about the differences are given.

Abstract: Along the process of setting and hardening in concrete, the temperature profile shows gradually a nonlinear distribution due to the development of hydration heat of cement. More specifically, at early ages of concrete structures, this nonlinear distribution has a large influence on the crack evolution. As a result, to obtain the exact temperature history, it is necessary to examine thermal properties of the concrete. In this study, the convective heat transfer coefficient, which presents heat transfer between concrete surface and air ambient, was experimentally investigated with test variables such as velocity of wind, type of form, and water-cement ratio.

Abstract: High-rise buildings in the city center construction has been with diversify disposition. As there is high wind on top of high-rise buildings, wind turbines are often installs on top of high-rise buildings. However, we can expect efficient power generation only by installing when the turbine in the place of heavy wind. In this article, it tries to evaluate wind power generation by performing airflow analysis around the roof according to the disposition of high-rise buildings.

Abstract: The development of downtown areas causes urban heat island (UHI), which raises the temperature of cities. To remove the causes of UHI, extensive research is underway for securing green spaces and fresh air corridors in urban districts. The development of high-rise apartments in the downtown affected the fresh air corridor of the whole city, decreasing wind velocity by up to 50% compared to that before the development. In addition, with regard to apartment layout in complexes, the front-rear inter-building distance had a higher effect on the change of wind velocity in the complexes than the side-to-side inter-building distance. However, in a layout with the same repetitive form, a wide side-to-side space increased the intensity of turbulent flow in the complex, making the wind velocity almost three times higher at some parts.

Abstract: The flat plate collector is one of the most widely used device for harnessing solar energy. Measurement of various losses occurring in a flat plate collector is important for design as well as evaluation for efficiency under different conditions. The major part of overall heat loss is the top heat loss. The various losses such as bottom loss, side loss, edge loss, corner loss, sealing loss & top loss etc, are measured as well as recorded. There are forty eight thermocouples located at different points.

Abstract: A bridge, which is located in the route of typhoon, is considered how to assure normal traffic use against strong winds. As one of the measures, wind barrier is proposed to be set on both sides of the bridge section for reducing wind velocity across it. In this study, an analysis by using CFX, a computational fluid dynamics program, is carried out to investigate the effects of wind barrier. The speed of wind is assumed as 60m/s. To find out an efficient design of the boards, different porosity ratios(r) of the boards is assumed for comparison. The result shows that wind barrier could reduce the wind speed across the bridge effectively.