Wszystkie pola: gust wind - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Intact stability of a bulk carrier
Autorzy:: Kałkowska, E.
Powiązania:: https://bibliotekanauki.pl/articles/135612.pdf
Data publikacji:: 2017
Wydawca:: Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:: intact stability
floodability
loadcase
lever
gust wind
steady wind
Opis:: Due to the accelerating demand for transporting raw materials around the world over the last century, bulk carriers are being constantly developed in order to maximise their capacity and efficiency whilst maintaining safety and durability of the vessels. With regards to safety, the International Maritime Organisation (IMO) and the International Association of Classification Societies (IACS) recurrently issue regulations and technical standards for the design and construction of ships, in order to safeguard the crew and other people on board. In light of these regulations, three issues concerning the properties of a bulk carrier are investigated. Firstly, the floodability of a bulk carrier is researched, to determine the largest possible volumes of compartments which can be flooded without causing the bulk carrier to capsize. Results were determined both manually and by means of marine design software, Maxsurf Enterprise; results generated by the two methods are compared. Additionally, a series of loadcases, each consisting of a different cargo and ballast configuration, are sought to reveal their effect on both the still water bending moment and the intact stability of the vessel. The results are analysed in relation to the IMO’s criteria.
Źródło:: Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2017, 49 (121); 65-68
1733-8670
2392-0378
Pojawia się w:: Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Assessment of Hazard from Damaging Wind Gusts in the Siedlce Area
Autorzy:: Radzka, Elżbieta
Olszewska, Eliza
Powiązania:: https://bibliotekanauki.pl/articles/2173241.pdf
Data publikacji:: 2022
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: wind direction
wind speed
wind gust
hazard
Opis:: The average daily values of wind speed and wind gust speed in the years 2001–2018 in Siedlce were analyzed. In the study area, the frequency of individual wind directions was determined and, according to criteria set by the Government Centre for Security, the frequency of hazards from damaging wind gusts was evaluated. The following wind gusts were considered: >20 m/s, 25 m/s and 35 m/s. It was found that, in the Siedlce area, the prevailing wind direction was west-south-westerly (WSW), and the average annual wind speed in the long-term study period was 2.99 m/s. March, April and May were the months when the highest speeds of maximum wind gusts (>35 m/s) were recorded. Extreme wind gusts the speed of which poses a hazard to the environment, national economy as well as human life and health, occurred in both the cold and warm seasons of the year.
Źródło:: Journal of Ecological Engineering; 2022, 23, 7; 192--196
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Convective and non-convective wind gusts in Poland, 2001-2015
Autorzy:: Kolendowicz, L.
Taszarek, M.
Czernecki, B.
Powiązania:: https://bibliotekanauki.pl/articles/108594.pdf
Data publikacji:: 2016
Wydawca:: Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:: wind gust
thunderstorm
convective
non-convective
severe weather
Polska
Opis:: The main aim of the article is to present the climatology of the peak wind gust frequency in Poland caused by the impact of both atmospheric circulation and the presence of thunderstorm clouds. Nine meteorological stations for the measurement period of 2001-2015 were taken into account. Only SYNOP reports with a peak wind gust higher or equal to 15 m s-1 in thunderstorm and non-thunderstorm days are considered in this study. The results indicate that the highest threat in terms of frequency and strength of peak wind gusts due to convection occurs in July. In winter, thunderstorms are rare, but if they occur, about 80% of them produce wind gusts exceeding a threshold of 15 m s-1. Peak wind gusts in a non-thunderstorm days are the highest and the most frequent in January, and are at a minimum during summer. Comparing both types, peak wind gusts during days with a thunderstorm were on average stronger than those without an involved convection. This indicated that convection was an important factor in enhancing the strength of a wind gust. The highest value in our base was 34 m s-1, recorded in Kraków on 8th July 2015 within the occurrence of a severe thunderstorm, while the highest value in a day without a thunderstorm was 33 m s-1, recorded in Łódź on 31st January 2002.
Źródło:: Meteorology Hydrology and Water Management. Research and Operational Applications; 2016, 4, 2; 15-21
2299-3835
2353-5652
Pojawia się w:: Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Adaptacyjna absorpcja obciążeń od ekstremalnych podmuchów wiatru w turbinach wiatrowych
Extreme gust load alleviation in wind turbines
Autorzy:: Mróz, A.
Powiązania:: https://bibliotekanauki.pl/articles/31343099.pdf
Data publikacji:: 2013
Wydawca:: Instytut Podstawowych Problemów Techniki PAN
Tematy:: turbina wiatrowa
obciążenia
aerodynamika
wind turbine
load
aerodynamics
Opis:: W pracy przedstawiono koncepcję łagodzenia skutków działania ekstremalnych podmuchów wiatru na łopaty turbin wiatrowych. Zaproponowane zostało uzupełnienie istniejących, aktywnych mechanizmów nastawiania kąta łopaty o dodatkowy system, który umożliwia redukcję naprężeń w nasadzie łopaty w trakcie narastania ekstremalnych podmuchów wiatru. Zaprezentowane rozwiązanie półaktywne nie wymaga wprowadzania dodatkowych źródeł ani akumulatorów energii, gdyż wykorzystuje ono energię obecną w strumieniu powietrza do tego, aby szybko obrócić łopatę w kierunku położenia "w chorągiewkę" i w ten sposób złagodzić narastające w trakcie podmuchu obciążenia aerodynamiczne. Opracowany został własny model numeryczny w oparciu o metodę modalną oraz teorię pasową strumienia śmigłowego. Wykonano szereg symulacji pięciomegawatowej turbiny wiatrowej, w tym obliczenia obejmujące pracę w stanie ustalonym, odpowiedź na ekstremalny podmuch wiatru, a także proces hamowania awaryjnego. Wykazano, iż możliwe jest szybkie zredukowanie obciążeń aerodynamicznych działających na łopaty turbiny wiatrowej przez wysprzęglenie skrętnego połączenia łopaty z piastą, i następnie kontrolę procesu obrotu łopaty wokół swojej osi w trakcie narastania podmuchu wiatru. Średnia prędkość obrotu łopaty może być znacząco wyższa niż maksymalne prędkości uzyskiwane przez istniejące mechanizmy nastawiania kąta łopaty. Celem drugiej części pracy było wykazanie, na drodze prostego doświadczenia w tunelu aerodynamicznym, że łopaty wirnika wyposażone w odpowiedni mechanizm wraz z układem sterowania, mogą obrócić się w kierunku ustawienia "w chorągiewkę” oraz, że obrotowi takiemu towarzyszy spadek obciążeń aerodynamicznych w nasadzie łopaty. W oparciu o hamulec magnetoreologiczny zaprojektowane zostało połączenie łopaty i piasty o regulowanej sztywności skrętnej. Testy przeprowadzono na modelowej turbinie wiatrowej o średnicy dwóch metrów. Ponadto wykonano szereg symulacji numerycznych w celu porównania wyników testów z odpowiedzią modelu numerycznego i uzyskano zadowalającą zgodność wyników.
A new concept of extreme operating gust loads alleviation in wind turbines has been presented. A new system has been proposed, as an extension of existing, active pitch control mechanisms, which allows for reduction of stresses in a blade root, in response to a rising extreme gust. No energy sources or accumulators are required in the proposed semi-active solution as it utilizes the energy of the wind stream in order to turn the blade to feather and thus mitigate the aerodynamic loads induced during the rise of an extreme gust. The aim for the carried out numerical simulations was to demonstrate the effectiveness of the solution at the theoretical, academic level. A numerical model has been elaborated based on the Modal method and Blade Element Momentum (BEM) theory. A number of numerical simulations has been carried out for a five megawatt turbine, including steady state analysis, extreme operating gust response and emergency braking. Numerical results show that it is feasible to rapidly reduce aerodynamic loads acting on a wind turbine blades by means of unclutching the torsional connection between the blade and the hub and controlling the rotation process in response to a sudden gust. The average rotational velocity of the unclutched blade may significantly exceed maximum velocities obtained by existing pitch control mechanisms. The goal of a simple experiment in a wind tunnel described in the second part of the work was to prove that the wind turbine blades equipped with the adaptive clutch together with control system may be turned to feather under aerodynamic torsional moment and this is accompanied by the decrease in remaining reaction moments in the blade root. The core of the adaptive device was a magnetoreological clutch capable to adjust the torsional stiffness of the blade root. The tests were carried out on a two-meter diameter model wind turbine with tensometers in the blade roots allowing for monitoring of the blade root reaction forces.
Źródło:: IPPT Reports on Fundamental Technological Research; 2013, 6; 1-158
2299-3657
Pojawia się w:: IPPT Reports on Fundamental Technological Research
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Warunki meteorologiczne powstania szkód wiatrowych w dniach 11-12 sierpnia 2017 roku w lasach środkowo-zachodniej Polski
Meteorological conditions of the occurrence of wind damage on August 11-12, 2017 in the forests of central-western Poland
Autorzy:: Chojnacka-Ożga, L.
Ożga, W.
Powiązania:: https://bibliotekanauki.pl/articles/986621.pdf
Data publikacji:: 2018
Wydawca:: Polskie Towarzystwo Leśne
Tematy:: lesnictwo
lasy
szkody w lesie
szkody od wiatru
warunki meteorologiczne
wiatry
Polska Srodkowo-Zachodnia
mesoscale convective system
wind gust
forest damage
Opis:: Climate change, which was particularly marked at the turn of the 20th and 21st centuries, was accompanied by unfavourable weather phenomena. One of whose effects cannot be prevented is hurricane. Much of the most devastating storms (e.g. Kyrill in January 2007, Carmen in November 2010), which crossed over Poland, was associated with low pressure systems. The occurrence of high wind speeds in the cold season is a natural feature of Polish climate. Hurricanes in the summer are generally characterized by more complicated origin. The cause of the damage at this time of year may be squall fronts and tornados (e.g. July 4th, 2002 – Puszcza Piska; July 20th, 2007 – Częstochowa region). An important issue is to develop a category of winds for the forest district, which can have destructive effect on the stands. Current research shows that gusty winds exceeding 11 m/s may cause first damage to the trees, while blows with velocity exceeding 30 m/s result in severe damage. Knowing and monitoring the mechanisms that leads to strong winds, assessing their impact, and managing risk in the context of their effects is one of the important elements of a forest management strategy. On August 11th, 2017, after the influx of hot tropic air, much cooler polar air began to flow from the west. In the afternoon and evening storm cell and supercell began to form in the south−west of the country. Later on, they moved in the north direction forming a squall line. With a Mesoscale Convective System (MCS) moving to the north, there was a gusty wind exceeding 40 m/s in some places. A gust of wind occurred around 18.30 (EET) in Dolny Śląsk (SW Poland) and after about 2 hours in Pomerania (N Poland). The pressure tendency during the transition reached 4−5 hPa. In the northern part of the country, gusts of wind were the largest and occurred several times in 2−3 hours. The system was accompanied by heavy precipitations, which in north Poland determine more than 60% of the average monthly rainfall. The effect of moving MCS was the damage of almost 80 thousand hectares of forests in Poland, which of more than 39 thousand hectares were classified to complete restoration.
Źródło:: Sylwan; 2018, 162, 03; 200-208
0039-7660
Pojawia się w:: Sylwan
Dostawca treści:: Biblioteka Nauki

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