scholarly journals The Relationship Between Opening Size and Critical Wind Speed of Smoke Overflow under Ambient Wind

2018 ◽  
Vol 211 ◽  
pp. 581-589
Author(s):  
Zhong-lin Quan ◽  
Ru Zhou ◽  
Jing-jing Lei ◽  
Cheng-yu Gong ◽  
Jun-cheng Jiang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Ambient Wind ◽  
Critical Wind Speed ◽  
The Relationship

Prediction of Fire Spread in Grasslands

1998 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
NP Cheney ◽  
JS Gould ◽  
WR Catchpole
Keyword(s):  
Wind Speed ◽  
Linear Relationship ◽  
Power Function ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Critical Wind Speed ◽  
Rate Of Spread ◽  
The Relationship ◽  
Potential Rate

This pager describes a model to predict fire spread in grasslands from wind speed at 10 m, dead fuel moisture, and degree of grass curing in three defined pasture types, The model was developed from spread measurements of experimental fins that were adjusted to their potential rate of spread at wide fronts. Extrapolations of the model were compared with spread data from 20 major wildfires in Australia. This model uses different functions to describe the relationship between rate of spread and wind speed above and below a critical wind speed of 5 km h-1. A linear relationship is used below 5 km h-1; above 5 km h-1 rate of spread is described by a power function of wind speed with an exponent of less than 1.

scholarly journals Mass Balance Sensitivity and Future Projections of Rabots Glaciär, Sweden

Climate ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 126
Author(s):  
Moon Taveirne ◽  
Laura Ekemar ◽  
Berta González Sánchez ◽  
Josefine Axelsson ◽  
Qiong Zhang
Keyword(s):  
Wind Speed ◽  
Mass Balance ◽  
Climate Scenario ◽  
Summer Temperature ◽  
Glacier Mass Balance ◽  
Northern Sweden ◽  
Dramatic Decrease ◽  
Future Projections ◽  
Modelling Studies ◽  
The Relationship

Glacier mass balance is heavily influenced by climate, with responses of individual glaciers to various climate parameters varying greatly. In northern Sweden, Rabots Glaciär’s mass balance has decreased since it started being monitored in 1982. To relate Rabots Glaciär’s mass balance to changes in climate, the sensitivity to a range of parameters is computed. Through linear regression of mass balance with temperature, precipitation, humidity, wind speed and incoming radiation the climate sensitivity is established and projections for future summer mass balance are made. Summer mass balance is primarily sensitive to temperature at −0.31 m w.e. per °C change, while winter mass balance is mainly sensitive to precipitation at 0.94 m w.e. per % change. An estimate using summer temperature sensitivity projects a dramatic decrease in summer mass balance to −3.89 m w.e. for the 2091–2100 period under climate scenario RCP8.5. With large increases in temperature anticipated for the next century, more complex modelling studies of the relationship between climate and glacier mass balance is key to understanding the future development of Rabots Glaciär.

scholarly journals Hubungan Kecepatan Pendinginan Air dengan Kecepatan Tiupan Udara

2017 ◽  
Vol 2 ◽  
pp. 241
Author(s):  
Taat Guswantoro ◽  
Manogari Sianturi ◽  
Nurafni Prapitasari ◽  
Areli Elona
Keyword(s):  
Regression Analysis ◽  
Wind Speed ◽  
Linear Regression ◽  
Water Temperature ◽  
Rate Of Change ◽  
Hot Water ◽  
Water Cooling ◽  
Exponential Regression ◽  
The Relationship

<p class="AbstractEnglish"><strong>Abstract</strong>: In this study hot water was placed in two erlenmeyer scale 100 ml clogged and without plug, each filled with 150 ml hot water and allowed to cool in air. Measurement of water temperature using sensor connected to the interface and recorded using the pasco capstone 14.1. The wind is raised with the fan, to adjust the wind speed by adjusting the fan distance, the speed is measured using an anemometer. The water cooling constant is obtained by a decay exponential regression analysis of temperature vs time. The relationship between water colling coefficient with wind speed is used linear regression. From the research, the water cooling coefficient naturally for clogging erlenmeyer is 3,1 x 10<sup>-4</sup> s<sup>-1</sup> and for erlenmeyer without plug 3.8 x 10<sup>-4</sup> s<sup>-1</sup>, the rate of change of water cooling constant to wind speed is 1 , 4 x 10<sup>-4</sup> m<sup>-1</sup>.</p><p class="KeywordsEngish"> </p><p class="AbstrakIndonesia"><strong>Abstrak: </strong>Pada penelitian ini air panas ditempatkan dalam dua buah erlenmeyer berskala 100 ml bersumbat dan tanpa sumbat, masing-masing diisi air panas dengan volume 150 ml dan dibiarkan mendingin di udara. Pengukuran suhu air dengan menggunakan sensor panas yang dihubungkan ke interface dan dicatat menggunakan program pasco capstone 14.1. Angin dibangkitkan dengan kipas, untuk mengatur kecepatan angin dengan cara mengatur jarak kipas, kecepatan angin diukur menggunakan anemometer. Konstanta pendinginan air diperoleh dengan analisis regresi eksponensial meluruh dari data suhu dan waktu. Hubungan antara koefisien pendinginan air dengan kecepatan angin digunakan regresi linier. Dari penelitian diperoleh koefisien pendinginan air secara alami untuk erlenmeyer tersumbat sebesar 3,1 x 10<sup>-4</sup> s<sup>-1</sup> dan untuk erlenmeyer tanpa sumbat sebesar  3,8 x 10<sup>-4</sup> s<sup>-1</sup>, laju perubahan konstanta pendinginan air terhadap kecepatan angin adalah sebesar 1,4 x 10<sup>-4</sup> m<sup>-1</sup><sub>.</sub></p>

scholarly journals Improvement of Snowgauge Collection Efficiency through a knowledge of solid precipitation fallspeed

2021 ◽  
Author(s):  
Nicolas R. Leroux ◽  
Julie M. Thériault ◽  
Roy Rasmussen
Keyword(s):  
Wind Speed ◽  
Transfer Function ◽  
Transfer Functions ◽  
Collection Efficiency ◽  
Particle Diameter ◽  
Field Site ◽  
Solid Precipitation ◽  
Gauge Data ◽  
The Relationship ◽  
Measured Particle

AbstractThe collection efficiency (CE) of a typical gauge-shield configuration decreases with increasing wind speed, with a high scatter for a given wind speed. The scatter in the CE for a given wind speed arises in part from the variability in the characteristics of falling snow and atmospheric turbulence. This study uses weighing gauge data collected at the Marshall Field Site near Boulder, Colorado during the WMO Solid Precipitation InterComparison Experiment (SPICE) to show that the scatter in the collection efficiency can be reduced by considering the fallspeed of solid precipitation particle types. Particle diameter and fallspeed data from a laser disdrometer were used to arrive at this conclusion. In particular, the scatter in the CE of an unshielded snow gauge and a single Alter shield snow gauge is shown to be largely produced by the variation in measured particle fallspeed. The CE was divided into two classes depending on the measured mean-event particle fallspeed. Slower-falling particles were associated with a lower CE. A new transfer function (i.e. the relationship between CE and other meteorological variables, such as wind speed or air temperature) that includes the fallspeed of the hydrometeors was developed. The RMSE of the adjusted precipitation with respect to a weighing gauge placed in a Double Fence Intercomparison Reference was lower than using previously developed transfer functions. This shows that the measured fallspeed of solid precipitation with a laser disdrometer accounts for a large amount of the observed scatter in weighing gauge collection efficiency.

scholarly journals Wavelet Analysis of Daily Energy Demand and Weather Variables

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Abdou Latif Bonkaney ◽  
Ibrah Seidou Sanda ◽  
Ahmed A. Balogun
Keyword(s):  
Wind Speed ◽  
Phase Analysis ◽  
Energy Demand ◽  
Electricity Demand ◽  
Weather Variables ◽  
Daily Energy ◽  
Wavelet Transform Coherence ◽  
Average Coherence ◽  
The Relationship ◽  
Insight Into

In this paper, we applied the Wavelet Transform Coherence (WTC) and phase analysis to analyze the relationship between the daily electricity demand (DED) and weather variables such as temperature, relative humidity, wind speed, and radiation. The DED data presents both seasonal fluctuations and increasing trend while the weather variables depict only seasonal variation. The results obtained from the WTC and phase analysis permit us to detect the period of time when the DED significantly correlates with the weather variables. We found a strong seasonal interdependence between the air temperature and DED for a periodicity of 256-512 days and 128-256 days. The relationship between the humidity and DED also shows a significant interdependence for a periodicity of 256-512 days with average coherence equal to 0.8. Regarding the radiation and wind speed, the correlation is low with average coherence less than 0.5. These results provide an insight into the properties of the impacts of weather variables on electricity demand on the basis of which power planners can rely to improve their forecasting and planning of electricity demand.

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