Wind energy development on lower Silesia province

The aim of this paper is to present issues related to the development of wind energy in the province of Lower Silesia. The first part of the paper based on the source materials presents conditions for the development of wind energy. Only 25% of the province area is an area of the lowest conflicting potential. In Lower Silesia, there is only one wind turbine, but the economic factors increase the inter-est in these investments. In order to designate areas for the location of wind farms many municipalities in the Lower Silesia began in recent years to create the spa-tial development plans or to change them. The study shows the involvement of the investment process based on selected municipalities of this province. The basis for the sustainable development of wind energy should be well considered spatial management. Location decisions must be preceded by a deep analysis of natural, social and landscape conditions. Such process may limits the formation of invest-ment conflicts. ...

Weather risk in the performance of maintenance works in watercourses

Occurence of minus air temperature, precipitation and wind worsen tech-nical conditions of the performance of maintenance works and it also has an impact on the occupational safety. Some of the results of considered weather events are the delays in the performance of particular works and an increase of their costs in a result of additional works. Potential financial loss that may influence enterprise in a result of unfavourable weather conditions is determined as the weather risk. In the following research the level of the risk in maintenance works in watercourses was assessed. The analysis of the weather forms was conducted in Wrocław between 2000 and 2011 for that purpose. Three weather conditions such as the air temperature below 0, rainfall, snowfall and the velocity of the wind were considered. Analysis was conducted basing on the data obtained from the Wroclaw Airport station. It was performed for the period recommended for the performance of maintenance works in watercourses from the 1st to the 31st of December. Frequency of the days occurence while weather conditions constituted an obstacle was determined basing on the obtained data. The analysis revealed that unfavourable weather conditions occurred often in realization of the works in the considered ...

This paper presents influence of direction and energy of wind on forming of ventilation air velocity in chosen area of the free stall barn during summer. Based on analysis of obtained measurement results characteristics of the wind speed in summer was made. Variability of the ventilation air velocity with take into account of perpendicular and parallel wind direction was determined. Noticed differentiation of air velocity depending on measurement place - central barn area was less ventilated than area close to wall. Proposals setting out the reasons for the abnormal air flow were formulated. In order to increased ventilation air velocity in central part of the barn recommended use to air mixers. Attention was drawn to need of continue studies of different barn types relative to building construction solution and its localization.     ...

wind, airflow resistance, kinetic friction

The article describes the effect of substrate roughness on the generation of air flow resistance and the occurrence of kinetic friction. These are the two main factors influencing reduction in wind speed, lack of ventilation in built-up areas, and stagnation of pollution over areas with high substrate roughness. The work presents the results of the authors' own measurements in the field, carried out using WindLog and CHY 361 anemometers, in two different types of atmospheric conditions - sunny and rainy weather. The measurements were taken on a stretch of the Rudawa River, located on the Cracow city limits. Wind speed was measured at all established measurement points. The immediate surroundings of the points varied in terms of how densely the areas were built up. The effect of changes in the shape and equivalent diameter of the measurement profile on the magnitude of flow resistance and friction was also tested. The results of the study indicate that the best type of arrangement for buildings around the valley of the Rudawa River is a latitudinal configuration. The lack of buildings on the path along which the airstream flows creates suitable conditions for ventilation of the city, and thus for clearing the air ...