Further Analysis of Non-Gaussian Wind Pressure Peak Factor Calculation

The wind pressure time history of high-rise building cladding is mostly non-Gaussian distribution, and there is a one-to-one correspondence between a specified guarantee rate and its corresponding peak factor. A stepwise search method for calculating the peak factor of non-Gaussian wind pressure and a gradual independent segmentation method for extracting independent peak values have been proposed to determine the relationship accurately in the previous study. Based on the given experiment and calculation results in the existing research results, more analysis can be given to enrich the study on this topic. In this paper, some characteristics of wind pressure coefficient time series in time and frequency domain are analysed. Based on the basic theory of fractal, the R/S analysis of wind pressure time series is made, and the fractal characteristics of wind pressure coefficient time series are explained. Based on the statistical theory, the relationship characteristics between high-order statistics and peak factors are studied. The correlation between the guarantee rate and the corresponding peak factor is analysed, and the guarantee rates calculated by the Davenport peak factor method are evaluated. The power spectrum characteristics of fluctuating wind pressure are analysed and the relationship between turbulence characteristic frequency and optimal observation time interval is discussed.

Characteristics of Typhoon “Fung-Wong” Near Earth Pulsation

To study the wind field characteristics near the ground pulsation in typhoon conditions, wind field conditions in the area affected by Typhoon “Fung-Wong” were monitored using wind field instruments installed in the construction building of Wenzhou University, China. Real-time wind field data were collected during typhoons. Wind characteristic parameters such as mean wind speed, wind direction angle, turbulence intensity, gust factor, peak factor, coherence function, and autocorrelation were analyzed, and the wind field characteristics during the typhoon were summarized. The results indicated that the longitudinal and lateral turbulence intensities decreased with an increase in the mean wind speed, and there was an obvious linear relationship between them. The vertical and horizontal gust factor and peak factor decreased with an increase in mean wind speed, and the trend was more obvious in the horizontal direction. There was a significant correlation between the gust factor and the peak factor. The turbulence intensity and gust factor decreased with time, and the turbulence intensity attenuation speed increased with time. The empirical curve presented by Davenport (1961) can simulate the correlation characteristics of the fluctuating wind speed components of Typhoon Fung-Wong at some measuring points. With an increase in the time difference, the dependence of the instantaneous values at the two time points gradually decreased.

Spatial Aggregation Effect on Water Demand Peak Factor

A methodological framework for the estimation of the expected value of hourly peak water demand factor and its dependence on the spatial aggregation level is presented. The proposed methodology is based on the analysis of volumetric water meter measurements with a 1-h time aggregation, preferred by water companies for monitoring purposes. Using a peculiar sampling design, both a theoretical and an empirical estimation of the expected value of the peak factor and of the related standard error (confidence bands) are obtained as a function of the number of aggregated households (or equivalently of the number of users). The proposed methodology accounts for the cross-correlation among consumption time series describing local water demand behaviours. The effects of considering a finite population is also discussed. The framework is tested on a pilot District Metering Area with more than 1000 households equipped with a telemetry system with 1-h time aggregation. Results show that the peak factor can be expressed as a power function tending to an asymptotic value greater than one for the increasing number of aggregated households. The obtained peak values, compared with several literature studies, provide useful indications for the design and management of secondary branched pipes of water distribution systems.

Studi Kuantitas Air Buangan Kampus Universitas Andalas Limau Manis Padang

<p>In this study, the quantity of wastewater from the existing facilities at the Andalas University Campus was carried out. The measured wastewater consists of grey water, black water, and specific wastewater. The wastewater was classified based on its activities, namely dormitories, lecture room, student facilities, offices, religious facilities, cafeterias, sports facilities, laboratories, and campus bus pools. The sampling method used was the bucket method. Grey water sampling was carried out on regular days (Monday-Thursday), worship days (Friday), and holidays (Saturday and Sunday), while specific wastewater and black water were measured on regular days. Peak hours occur at 12.00-14.00 except in the dormitory at 06.00-08.00 and cafeteria at 10.00-11.00. The peak factor of used water ranges from 1.56 to 3.13. From the measurement results obtained the wastewater from dormitory wastewater of 212.8 m³/day; lecture building 491 m³/day; student facilities 32.4 m³/day; offices 245.4 m³/day; worship 50.4 m³/day; cafeteria 109.2 m³/day; sports facilities 8.7 m³/day; laboratory 282 m³/day; corral 27 m³/day; and pool bus 34.7 m³/day respectively. The total wastewater from Unand Limau Manis Campus is 1,439.6 m³/day. The wastewater composition consists of, grey water 812.3 m³/day (52.67%), specific wastewater 343.8 m³/day (23.45%) and 337.5 m³/day (23.88%) black water.</p>