Добірка наукової літератури з теми "Protection from ice-wind loads"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Protection from ice-wind loads".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Protection from ice-wind loads"
1
Getz, David, and Jose Palacios. "Design procedures and experimental verification of an electro-thermal deicing system for wind turbines." Wind Energy Science 6, no. 5 (October 6, 2021): 1291–309. http://dx.doi.org/10.5194/wes-6-1291-2021.
Повний текст джерелаАнотація:
Abstract. There has been a substantial growth in the wind energy power capacity worldwide, and icing difficulties have been encountered in cold climate locations. Rotor blade icing has been recognized as an issue, and solutions to mitigate accretion effects have been identified. Wind turbines are adapting helicopter rotor and propeller ice protection approaches to reduce aerodynamic performance degradation related to ice formation. Electro-thermal heating is one of the main technologies used to protect rotors from ice accretion, and it is one of the main technologies being considered to protect wind turbines. In this research, the design process required to develop an ice protection system for wind turbines is discussed. The design approach relies on modeling and experimental testing. Electro-thermal heater system testing was conducted at the Adverse Environment Rotor Test Stand at Penn State, where wind turbine representative airfoils protected with electro-thermal deicing were tested at representative centrifugal loads and flow speeds. The wind turbine sections tested were half-scale models of the 80 % span region of a generic 1.5 MW wind turbine blade. The icing cloud impact velocity was matched to that of a 1.5 MW wind turbine at full power production. Ice accretion modeling was performed to provide an initial estimate of the power density required to de-bond accreted ice at a set of icing conditions. Varying icing conditions were considered at −8 ∘C with liquid water contents of the cloud varying from 0.2 to 0.9 g/m3 and water droplets from 20 µm median volumetric diameter to 35 µm. Then, ice accretion thickness gradients along the span of the rotor blade for the icing conditions were collected experimentally. Given a pre-determined maximum power allocated for the deicing system, heating the entire blade was not possible. Heating zones were introduced along the span and the chord of the blade to provide the required power density needed to remove the accreted ice. The heating sequence for the zones started at the tip of the blade, to allow de-bonded ice to shed off along the span of the rotor blade. The continuity of the accreted ice along the blade span means that when using a portioned heating zone, ice could de-bond over that specific zone, but the ice formation could remain attached cohesively as it is connected to the ice on the adjacent inboard zone. To prevent such cohesive retention of de-bonded ice sections, the research determined the minimum ice thickness required to shed the accreted ice mass with the given amount of power availability. The experimentally determined minimum ice thickness for the varying types of ice accreted creates sufficient tensile forces due to centrifugal loads to break the cohesive ice forces between two adjacent heating zones. The experimental data were critical in the design of a time sequence controller that allows consecutive deicing of heating zones along the span of the wind turbine blade. Based on the experimental and modeling efforts, deicing a representative 1.5 MW wind turbine with a 100 kW power allocation required four sections along the blade span, with each heater section covering 17.8 % span and delivering a 2.48 W/in.2 (0.385 W/cm2) power density.
2
Vagapov, G. V. "Diagnostics of the ice on the strike protection wire." Power engineering: research, equipment, technology 21, no. 4 (December 9, 2019): 104–12. http://dx.doi.org/10.30724/1998-9903-2019-21-4-104-112.
Повний текст джерелаАнотація:
The relevance of the research problem is chose of effective technology of strike protection wire monitoring in span with use of technical system of analysis of technical condition of strike protection wire of 110 kV voltage power line for complex assessment of the impact of both external climatic factors from wind and ice loads and the magnitude of the thermal elongation of the strike protection wire with influence of current during de-icing process. Analysis of the strike protection wire mode and their limiting values of mechanical strength allow evaluation of the effectiveness of events of prevent of accidents and reduce the undersupply of electricity to the end consumers. Visualization of the operative parameters of the strike protection wire in the span of the overhead power line will allow reduce the time to make decisions on the prevention of accidents of lines. Algorithm of monitoring of operative parameters of wires of overhead power lines base on information of longitudinal and transverse angles received from sensors installed directly on the strike protection wire.
3
Cai, Pei, and Bing Tang Yang. "Design and Research of Smart Blades Based on Load Optimization and Power Control." Applied Mechanics and Materials 654 (October 2014): 229–32. http://dx.doi.org/10.4028/www.scientific.net/amm.654.229.
Повний текст джерелаАнотація:
Wind energy is the fastest growing source of energy nowadays. The significant growth of size and weight over the past few decades increase the cost of energy (COE) of wind turbines. Optimization of rapid fluctuating loads, which arise from a variety of sources including turbulence, tower shadow, wind shear and yawed flow, can lower the COE. In this article, the “Active Blade”, changing the local airfoil contour driven by a built-in structure to modify the blade’s aerodynamic performance, designed as a solution to reduce fatigue loads on wind turbines. In this approach, aerodynamic load control devices, combined with sensor, controller and actuator, dynamically control the blade loads. The structure is simple with good high frequency fast response performance. The overload stall protection effect is obvious and fast.
4
Koybakov, S. M., M. Maliktaiuly, S. K. Joldassov, G. A. Sarbasova,, and Zh Yeskermessov. "NEW METHODS TO PROTECT YEAR-AROUND OPERATION CANALS FROM SNOW." NEWS of National Academy of Sciences of the Republic of Kazakhstan 6, no. 444 (December 15, 2020): 102–9. http://dx.doi.org/10.32014/2020.2518-170x.136.
Повний текст джерелаАнотація:
On the canals of year-around operation, severe snowdrifts concentrated on the surface of the ice cover simultaneously affect both thermal and static loads. When ice melts intensively from the lower surface in areas of accumulation of snow masses, and also due to an increase in the static load from snow, longitudinal cracks form on the ice. The snow saturated with water rising up along the cracks, and a gradual sinking of the snow-ice mass occurs. All this leads to decrease in canal capacity, and in some cases to complete blockage of the flow section by snow-ice mass. The purpose of the paper is to find new ways to protect the canal drift and create an impervious canal profile in areas heavily covered in snow. Snow deposition in the canal bed occurs gradually, starting from the edge of canal closest to the snow collection basin side, followed by an increase in the snowdrift shaft in the direction of the wind as snow blizzard arrives to the canal. We propose the method of protecting the canals from snowdrifts by changing the transverse profile of the canal in the sections highly covered by snow. The transverse canal profile is changed by adding a berm to it with a slope coefficient equal to the coefficient the leeward slope and a height equal to the depth of the canal from the leeward slope depending on exact establishing the limit position of the surface of the snowdrifts, at which the canal is blown without snow deposition, regardless of the amount of snow transfer. The proposed methods can be applied in areas of snow transfer on watering and irrigation canals designed for year-around operation.
5
Dawson, TJ, and SK Maloney. "Fur versus feathers: the different roles of red kangaroo fur and emu feathers in thermoregulation in the Australian arid zone." Australian Mammalogy 26, no. 2 (2004): 145. http://dx.doi.org/10.1071/am04145.
Повний текст джерелаАнотація:
Fur or feathers provide protection against heat loads from solar radiation for birds and mammals. The red kangaroo (Macropus rufus) and the emu (Dromaius novaehollandiae) are conspicuous in arid environments of Australia where there is potential for high solar loads. The diurnal D. novaehollandiae feeds in the open yet it has a dark coat with a high absorptivity (83%), which contrasts with that of M. rufus (61%), but M. rufus generally shelters in shade during the day. We examined the effect of coat characteristics on the heat load from solar radiation at skin level. Coat depth and density (thermal conductance or insulation) and the level of penetration of solar radiation into the coat were important determinants of solar heat load. For M. rufus less than 25% of incident radiation reached the body at low wind speeds and this diminished to below 15% at moderate wind speeds. In the modest shade M. rufus seeks on summer days, their heat load from solar radiation appears minimal. Colour differences among M. rufus did not affect thermal load. D. novaehollandiae on the other hand is exposed to the full incident solar load in the open but its plumage provides almost complete protection from solar radiation. Solar radiation is absorbed at the feather surface and the insulation provided by the deep coat prevents heat transmission to the skin.
6
Vitalii V. Khomicky, Borys M. Ostroverkh, Viktor A. Tkachenko, Vladimir A. Voskoboinick та Lidiia M. Tereshchenko. "Іmprovement of protection dam of the мarine approach channel Danube-Black Sea". Environmental safety and natural resources 35, № 3 (17 вересня 2020): 57–77. http://dx.doi.org/10.32347/2411-4049.2020.3.57-77.
Повний текст джерелаАнотація:
One of the important tasks for Ukraine is to restore navigation on the mouth of the Danube Bistre, using it as a European-Asian way from the Baltic Sea to the Black Sea, and then to the East. Restoration of the deep-sea navigation of the Danube-Black Sea River has begun about ten years ago and has been progressing with great difficulty and interruptions. A protective enclosing dam of the Maritime approach channel of the Danube-Black Sea deep-water vessel was built in the water area of the Bystre estuary of the Kiliya Delta of the Danube River. This paper presents the results of mathematical and physical modeling of the improvement and reconstruction of the protection dam of the Maritime approach channel of the Danube-Black Sea deep-sea navigation. Numerical calculations of the transformation of wind waves in the water area near the dam for the most dangerous wind directions in stormy conditions are carried out. For mathematical modeling, the maximum values of wind and wave height were used, which were observed during the entire research period in the area of the dam. Within the framework of refraction theory, wave transformation calculations were performed for the most wave-dangerous directions of wind acceleration, namely, northeast, east, southeast and south wind directions. The results of calculations show that the construction of a protective dam at the exit of the Bystre estuary leads to a significant reduction in wave heights (almost twice) and their lengths by more than 1.5 times, which will ensure a smooth approach and exit of vessels to the Bystre estuary. To assess the characteristics of storm surges and wind waves in the study area was set "hypothetical" storm, when uniform in space and constant in time wind blows over the entire Black Sea. Simulations of wind waves were performed by the 3-step method of nested grids. Calculations were performed for twelve options directly. The morphodynamic calculations showed the areas of circulating near bottom currents inside the dam protected area and the peculiarities of the bottom deformation due to wave motion and storm rise of sea level. Experimental studies on a fragment of the dam model revealed the areas of greatest wave loads, features of wave transformation and pressure fields on the dam ridge. On the basis of theoretical and experimental researches the new step form of the dam which withstands storm wave loads is proposed.
7
Howlader, Abdul, Hidehito Matayoshi, Saeed Sepasi, and Tomonobu Senjyu. "Design and Line Fault Protection Scheme of a DC Microgrid Based on Battery Energy Storage System." Energies 11, no. 7 (July 12, 2018): 1823. http://dx.doi.org/10.3390/en11071823.
Повний текст джерелаАнотація:
Currently, the Direct-Current (DC) microgrid has been gaining popularity because most electronics devices require a DC power input. A DC microgrid can significantly reduce the AC to DC energy conversion loss. However, a power grid may experience a line fault situation that may damage important household devices and cause a blackout in the power system. This work proposes a new line fault protection scheme for a DC microgrid system by using a battery energy storage system (BESS). Nowadays, the BESS is one of the most cost effective energy storage technologies for power system applications. The proposed system is designed from a distributed wind farm smart grid. A total of three off-shore wind farms provide power to the grid through a high voltage DC (HVDC) transmission line. The DC microgrid was modeled by a BESS with a bi-directional DC–DC converter, various DC-loads with step down DC–DC converters, a voltage source converter, and a voltage source inverter. Details of the control strategies of the DC microgrid are described. During the line fault situation, a transient voltage was controlled by a BESS. From the simulation analyses, it is confirmed that the proposed method can supply stable power to the DC grid, which can also ensure protection of several loads of the DC microgrid. The effectiveness of the proposed system is verified by in a MATLAB/SIMULINK® environment.
8
Song, Y. D., Qian Cao, Xiaoqiang Du, and Hamid Reza Karimi. "Control Strategy Based on Wavelet Transform and Neural Network for Hybrid Power System." Journal of Applied Mathematics 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/375840.
Повний текст джерелаАнотація:
This paper deals with an energy management of a hybrid power generation system. The proposed control strategy for the energy management is based on the combination of wavelet transform and neural network arithmetic. The hybrid system in this paper consists of an emulated wind turbine generator, PV panels, DC and AC loads, lithium ion battery, and super capacitor, which are all connected on a DC bus with unified DC voltage. The control strategy is responsible for compensating the difference between the generated power from the wind and solar generators and the demanded power by the loads. Wavelet transform decomposes the power difference into smoothed component and fast fluctuated component. In consideration of battery protection, the neural network is introduced to calculate the reference power of battery. Super capacitor (SC) is controlled to regulate the DC bus voltage. The model of the hybrid system is developed in detail under Matlab/Simulink software environment.
9
McCaughey, Ward, Glenda L. Scott, and Kay L. Izlar. "Whitebark Pine Planting Guidelines." Western Journal of Applied Forestry 24, no. 3 (July 1, 2009): 163–66. http://dx.doi.org/10.1093/wjaf/24.3.163.
Повний текст джерелаАнотація:
Abstract This article incorporates new information into previous whitebark pine guidelines for planting prescriptions. Earlier 2006 guidelines were developed based on review of general literature, research studies, field observations, and standard US Forest Service survival surveys of high-elevation whitebark pine plantations. A recent study of biotic and abiotic factors affecting survival in whitebark pine plantations was conducted to determine survival rates over time and over a wide range of geographic locations. In these revised guidelines, we recommend reducing or avoiding overstory and understory competition, avoiding swales or frost pockets, providing shade and wind protection, protecting seedlings from heavy snow loads and soil movement, providing adequate growing space, avoiding sites with lodgepole or mixing with other tree species, and avoiding planting next to snags.
10
Triest, Jack, Robert Mulvaney, and Olivier Alemany. "Technical innovations and optimizations for intermediate ice-core drilling operations." Annals of Glaciology 55, no. 68 (2014): 243–52. http://dx.doi.org/10.3189/2014aog68a049.
Повний текст джерелаАнотація:
AbstractThe British Antarctic Survey, in collaboration with Laboratoire de Glaciologie et Géophysique de l’Environnement, has in recent years successfully drilled to bedrock on three remote sites around the Antarctic Peninsula. Based on the experience from the multi-season project at Berkner Island (948m depth, 2002–05) we optimized the drill set-up to better suit two subsequent single-season projects at James Ross Island (363m depth, 2008) and Fletcher Promontory (654m depth, 2012). The adaptations, as well as the reasons for them, are discussed in detail and include a drill tent set-up without a trench; drilling without a borehole casing with a relatively low fluid column height; and using a shorter drill. These optimizations were aimed at reducing cargo loads and installation time while maintaining good core quality, productivity and a safe working environment. In addition, we introduce a number of innovations, ranging from a new lightweight cable tensioning device and drill-head design to core storage and protection trays. To minimize the environmental impact, all the drill fluid was successfully recovered at both sites and we describe and evaluate this operation.
Дисертації з теми "Protection from ice-wind loads"
1
Меркотан, Роман Андрійович. "Захист проводів повітряних ліній електропередавання від галопування та ожеледно-вітрових навантажень". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23285.
Повний текст джерелаАнотація:
Магістерська дисертація складається з пояснювальної записки на 106 сторінках та графічної частини на 8 листах. В роботі наведено 46 рисунків та 13 таблиць. Робота містить такі розділи: 1. Загальні відомості щодо ожеледно-вітрових навантажень та коливань проводів ПЛ. 2. Моделювання коливань проводів ПЛ з урахуванням ожеледно-вітрових навантажень. 3. Методи та засоби захисту ПЛ від вібрації та галопування. 4. Методи та засоби захисту ПЛ від ожеледно-вітрових навантажень. Актуальність роботи: Одним з найголовніших принципів сучасної енергетики є забезпечення надійної та безперебійної роботи обладнання електроенергетичних систем і електричних мереж. Для повітряних ліній електропередавання одним з актуальних є питання їх захисту від зовнішніх впливів природного походження, таких як вітрові та ожеледно-вітрові навантаження. У зарубіжних країнах немає єдиної методики нормування розрахункових кліматичних умов для проведення їх районування за інтенсивністю ожеледоутворення, тому питання організації боротьби з різними видами відкладень на проводах ліній електропередавання на сьогоднішній день поставлене першочергово і є дуже актуальним. Для швидкого та точного вирішення цього питання необхідним є уточнення всіх існуючих знань та матеріалів щодо вітрових та ожел едно-вітрових навантажень, створення комп'ютерних моделей аналізу та прогнозування даних відкладень на проводах ліній електропередавання і створення нових методів та типів захисту ліній електропередавання від впливів природного походження Мета дисертаційної роботи: Аналіз і вивчення повного циклу виникнення ожеледних відкладень на лініях електропередавання з врахуванням впливу дії вітру, аналіз впливу та створення комп'ютерної моделі ожеледно-вітрових навантажень на проводи ліній електропередавання, запропонування методик та типів захисту ліній електропередавання від ожеледно-вітрових навантажень. Об’єкт дослідження: проводи повітряних ліній електропередавання усіх класів номінальних напруг. Предмет дослідження: процес виникнення ожеледних відкладень під дією вітру та їх вплив на проводи ліній електропередавання усіх класів номінальних напруг. Ключові слова: проводи ліній електропередавання, ожеледні відкладення, ожеледоутворення, ожеледно-вітрові навантаження, захист від ожеледно-вітрових навантажень.The master's dissertation consists of an explanatory note on 106 pages and graphic part on 8 paper. There are 46 pictures and 13 tables. The work contains the following sections: 1. General information on ice-wind loads and fluctuations of wires. 2. Modeling of fluctuations of wires of the power lines, taking into account the ice-wind loads. 3. Methods and means of protection of the submarine from vibration and galloping. 4. Methods and means of protection of submarines from ice-wind loads. Actuality of work: One of the most important principles of modern energy is to ensure reliable and uninterrupted operation of equipment of electric power systems and electric networks. One of the most urgent issues is to protect them from external influences of natural origin, such as wind and ice-wind loads. In foreign countries there is no uniform method of normalization of the calculated climatic conditions for their zoning based on the intensity of ice-forming, so the issue of organizing the fight against various types of deposits on the lines of transmission lines has been put to the fore today and is very topical. In order to quickly and accurately resolve this issue, it is necessary to clarify all existing knowledge and materials concerning wind and ice-wind loads, to create computer models of analysis and forecasting of these deposits on wires of power transmission lines and to create new methods and types of protection of transmission lines from natural influences. The purpose of the dissertation work: Analysis and study of the full cycle of occurrence of iced deposits on transmission lines, taking into account the influence of the wind, impact analysis and the creation of a computer model of ice-wind loads on the transmission lines, offering methods and types of protection of transmission lines from ice-wind loads. Object of research: conducting of overhead transmission lines of all classes of nominal voltages. Subject of research: the process of occurrence of iced ice deposits under the influence of wind and their influence on conduction lines of electric power transmission of all classes of nominal voltages.
Частини книг з теми "Protection from ice-wind loads"
1
"Mitigating Impacts of Natural Hazards on Fishery Ecosystems." In Mitigating Impacts of Natural Hazards on Fishery Ecosystems, edited by Hans W. Paerl and Benjamin L. Peierls. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874011.ch9.
Повний текст джерелаАнотація:
<em>Abstract</em>.—Since the mid-1990s, the U.S. mid-Atlantic region has witnessed a sudden rise in hurricane and tropical storm landfalls. In particular, eastern North Carolina has been impacted by eight hurricanes and six tropical storms in the past decade, and this relatively high frequency is forecast to continue for the next several decades. Each of the past storms exhibited unique hydrologic and nutrient loading scenarios for the Pamlico Sound, the United States’ second largest estuarine system and its largest subestuary, the Neuse River estuary. This variability represents a challenge to nutrient management aimed at protecting water quality and ensuring optimal fisheries habitat conditions. Different rainfall amounts among hurricanes led to variable freshwater and nutrient discharge and hence variable nutrient, organic matter, and sediment enrichment. These enrichments differentially affected physical and chemical properties (salinity, water residence time, transparency, stratification, dissolved oxygen), phytoplankton primary production, and phytoplankton community composition. The contrasting effects were accompanied by biogeochemical perturbations (hypoxia, enhanced nutrient cycling), benthic and planktonic habitat alterations, and possibly food web disturbances. Floodwaters from the two largest hurricanes, Fran (1996) and Floyd (1999), exerted multimonth to multiannual effects on hydrology, nutrient loads, productivity, biotic composition, and habitat condition. In contrast, relatively low rainfall coastal hurricanes like Isabel (2003) and Ophelia (2005) caused strong vertical mixing and storm surges but exhibited relatively minor hydrologic, nutrient, and biotic impacts. Both hydrologic and wind forcing are important drivers and must be integrated with nutrient loading in assessing short- and long-term ecological impacts of these storms. These climatic forcings cannot be managed but must be considered when developing water quality management strategies for these and other large estuarine ecosystems faced with increasing frequencies and intensities of hurricane activity.
2
Revki, Andrew C. "The Environment." In A Field Guide for Science Writers. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780195174991.003.0040.
Повний текст джерелаАнотація:
Hindsight is usually expressed in bravado-tinged phrases. “You have it so easy now” is one. But when scanning the recent history of environmental news, the impression is just the opposite. A few decades ago, anyone with a notepad or camera could have looked almost anywhere and chronicled a vivid trail of despoliation and disregard. Only a few journalists and authors, to their credit, were able to recognize a looming disaster hiding in plain sight. But at least it was in plain sight. The challenges in covering environmental problems today are far greater, for a host of reasons. Some relate to the subtlety or complexity of most remaining pollution and ecological issues now that glaring problems have been attacked. Think of non-point-source pollution, such as runoff from countless farm fields or urban lawns, and then think of the ultimate point of the Exxon Valdez, spilling its heavy load of crude oil into the seas off the Alaskan coast. A little reflection is useful. Most journalists of my generation were raised in an age of imminent calamity. Cold War “duck and cover” exercises regularly sent us to the school basement. The prospect of silent springs hung in the wind. We grew up in a landscape where environmental problems were easy to identify and describe. Depending on where you stood along the Hudson River's banks, the shores were variously coated with adhesive, dyes, paint, or other materials indicating which riverfront factory was nearest. And, of course, the entire river was a repository for human waste, making most sections unswimmable. Smokestacks were unfiltered. Gasoline was leaded. Then things began to change. New words crept into the popular lexicon—smog, acid rain, toxic waste. At the same time, citizens gained a sense of empowerment as popular protest shortened a war. A new target was pollution. Earth Day was something newspapers wrote about with vigor, not an anachronistic, even quaint, notion. Republican administrations and bipartisan Congresses created a suite of laws aimed at restoring air and water quality and protecting wildlife. And, remarkably, those laws began to work. Right through the 19805 the prime environmental issues of the day—and thus the news—continued to revolve around iconic incidents, mainly catastrophic in nature.
Тези доповідей конференцій з теми "Protection from ice-wind loads"
1
Gu¨rtner, Arne, and Joachim Berger. "Results From Model Testing of Ice Protection Piles in Shallow Water." In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92100.
Повний текст джерелаАнотація:
The development of oil and gas fields in shallow icy waters, for instance in the Northern Caspian Sea, have increased the awareness of protecting offshore structures by means of ice barriers from the impacts of drifting ice. Protection could be provided by Ice Protection Piles (IPPs), installed in close vicinity to the offshore structure to be protected. Piles then take the main loads from the drifting ice by pre-fracturing the advancing ice sheet. Hence, the partly shielded offshore structure could be designed according to significant lower global design ice loads. In this regard, various configurations of pile arrangements have been model tested during the MATRA-OSE research project in the Ice Model Test Basin of the Hamburg Sip Model Basin (HSVA). The main objective was to analyse the behaviour of ice interactions with the protection piles together with the establishment of design ice loads on an individual pile within the pile arrangement. The pile to pile distances within each arrangement were varied from 2 to 8 times the pile diameter for both, vertical and inclined (30° to the horizontal) pile arrangements. Two test runs with 0.1 m and 0.5 m thick ice (full scale values) were conducted respectively. The full scale water depth was 4 m. Based on the model test observations, it was found that the rubble generation increases with decreasing pile to pile distances. Inclined piles were capable to produce more rubble than vertical piles and considerable lower ice loads were measured on inclined arrangements compared to vertical arrangements. As initial rubble has formed in front of the arrangements, the rubble effect accelerated considerable. Subsequent to the build-up of rubble accumulations, no effect of the pile inclination on the exerted ice loads could be observed. If piles are used as ice barriers, the distance between the piles should be less than 4D for inclined piles and 6D for vertical piles to allow sufficient rubble generation. Larger distances only generated significant ice rubble after initial grounding of the ice had occurred.
2
Hansen, John W. "Protecting Mainline Valves From Ice Flows." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90257.
Повний текст джерелаАнотація:
In the spring of 2009, the Red River of North Dakota flooded six feet deep and ten miles wide in Pembina County. The flood was followed by arctic temperatures that froze the floodwaters 8-inches thick and also froze around the stems of seven isolation valves. These isolation valves were for pipelines carrying crude oil and natural gas liquid (NGL). The pipeline sizes varied from 36-inch to 18-inch diameters. The ice around the valves was subjected to wind forces of 50 mph putting the valves at risk. Also, when the second spring runoff came, the river current pulled ice down through the valley. This ice flow took out trees, power poles, and damaged a couple of isolation valves. The damage was minimal, but could have been worse. No leaks occurred. This paper will explore the unique problems associated with protecting the valves and delve into keys and principles that led to an innovative solution. Technical issues will be discussed that will help future projects solve problems on how to protect equipment from ice flows. The underlying soils were known for their excessive settlements and low shear strength. The soil was predicted to settle 6-inches after adding eleven feet of fill for protective berms. The preliminary pipe stress calculations based on the predicted settlement of 6-inches put the allowable pipe stress near the limits of acceptability. The valve site was also located miles from the nearest road. The forces from the ice loads in a river can be enormous and engineering judgment had to be used to obtain a practical solution.
3
Tikhonov, Vadim S., Dmitry V. Surkov, Alexander I. Safronov, and Michael Ya Gelfgat. "Interaction Between Drillstring and Ice-Protection Pipe While Drilling Deepwater Wells in Water Basins With Ice Sheets." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28628.
Повний текст джерелаАнотація:
While drilling deepwater stratigraphic wells in the water basins with ice sheets, drillers usually encounter the problem of a drillstring protecting from ice loads. One of the methods of the drillstring protection from ice impact provides for clearance installation of an ice pipe in the drilling vessel unit moonpool with the pipe bottom several meters below the keel. The paper suggests the numerical-analytical method of the stress-deformated state calculation for the drillstring and the ice-protection pipe with allowance for contact interaction between the drillstring, the ice protection pipe and the moonpool wall. The ice load value is determined based on the condition of equality between the kinetic energy of a moved ice floe and the elastic energy of the “drillstring – ice-protection pipe” system. The principle of the minimum potential elastic energy is used for calculating the system equilibrium configuration, with account to constraints of the system element displacement. The method of coordinate-by-coordinate descent is used to find a solution for the conditional minimization problem. The developed method is employed to evaluate the efficiency of the ice pipe design to be used while drilling deepwater stratigraphic wells from the Botnica multi-function icebreaker in the Arctic region under the International Ocean Drilling Program (IODP). The study showed that the suggested ice pipe design was capable of withstanding impacts of ice floes moving at 1.5 m/sec with thickness of 1 m and with diameter up to 3.5 m.
4
Phillips, Ryan, Tony King, and Jim Bruce. "PIRAM: Pipeline Ice Risk Assessment and Mitigation Program Overview." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90423.
Повний текст джерелаАнотація:
The Pipeline Ice Risk Assessment & Mitigation JIP (PIRAM) developed a set of engineering models and design procedures for implementation into industry best practices for risk mitigation and protection of pipeline infrastructure from ice keel loading. The models established the pipeline mechanical behaviour in response to ice keel load events, and assessed engineering concepts for protection and risk mitigation strategies. Improved methodologies for contact frequency and ice keel loads determination formed part of the integrated model. This paper presents an overview of this multiyear program and examples of the application of the models in pipeline burial depth assessment in pressure ridge ice gouged seabeds.
5
Hindley, Rob, Jillian Adams, Ville Valtonen, and Chi-Hyun Sung. "Dimensioning of Rudder Systems for Ice Class Ships." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18728.
Повний текст джерелаАнотація:
Abstract Rudder systems (rudder control surfaces and steering gear) are a safety critical element of ships operating in ice-covered waters. Icebreaking ships equipped with single rudders are particularly vulnerable considering the remote and often isolated locations in which they operate. The IACS Polar Class Rules were developed as a set of harmonized requirements for ships operating in polar waters. First published in 2006 the rules contain requirements for dimensioning the hull structure and propulsion machinery to resist ice loads. There are however no specific requirements for rudders — the rules simply require appendages to be dimensioned using the hull ice load. This paper presents a series of studies aimed at providing guidance on dimensioning rudders and steering gear systems for operation in ice. Using existing ship reference cases and rudder ice loading scenarios found in previous rules and guidelines a simplified set of design approaches are presented. These approaches are evaluated with Finite Element Analysis and compared with selected measured full-scale data and damage incidents. Guidance is provided on system protection mechanisms for the steering gear under these design and over-load cases. In addition, a comparison is made between the results and those derived from using the hull area design pressures in the current IACS rules.
6
Konuk, Ibrahim, Shenkai Yu, and Robert Gracie. "A 3-Dimensional Continuum ALE Model for Ice Scour: Study of Trench Effects." In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2005. http://dx.doi.org/10.1115/omae2005-67547.
Повний текст джерелаАнотація:
A new Arbitrary Lagrangian Eulerian (ALE) Finite Element (FE) model of ice scour was recently developed by the authors. It is based on continuum representation of the soil. It was shown in recent papers that such a model can characterize the mechanics of the ice-soil-pipeline interaction without requiring any of the assumptions that the Winkler models depend on. The model utilizes soil properties obtained by conventional laboratory testing. In a recent paper, this model was used to show that the subscour deformations and ice-soil interaction forces are very sensitive to ice ridge geometries for shallow slope ice features. In this paper, the ALE FE ice scour model is utilized to study the effects of the pipeline trench on the scour process and the forces transmitted to the pipeline. Two different infill soil properties and two different ice ridge geometries are analyzed with a 36 inch diameter pipe buried to in a trench of 1.5 m cover. It is shown that the scour process near and in the trench is significantly different than in the ambient seabed soils and the recognition of this may present some potential advantages for the protection of the pipelines not recognized by the Winkler models. It is also shown that the pipeline loads generated during the scour process are cyclic. They build slowly as the ice moves over the trench and then reverse as the ice ridge moves away from the trench. This is in contrast to monotonic and rapidly growing loads predicted by the Winkler models. The paper shows that the loads transferred to the pipeline depend on the infill soil properties placed in the trench. It is shown that loads experienced by the pipeline are less for the softer infill than stiffer soils.
7
LaMalva, Kevin J. "ASCE/SEI Advancements in Structural Fire Engineering." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.0719.
Повний текст джерелаАнотація:
<p>Advancements put forth by the Structural Engineering Institute (SEI) of ASCE are paving the way for a regulated engineered alternative to the long‐standing archaic requirements for structural fire design. For the past century, project stakeholders have tolerated a strikingly inefficient and amorphous system for protecting structures from uncontrolled fire. Traditionally, fire protection is prescribed for structures after they have been optimized for ambient design loads (i.e., gravity, wind, seismic, and others), with no explicit consideration of structural fire performance. Accordingly, the vulnerability of buildings to structural failure from uncontrolled fire is presumably variable across different jurisdictions, which have varying structural design requirements for ambient loads. Also, structural engineers are often absent from the structural fire protection design process entirely.</p><p>In conjunction with new provisions in Appendix E of Minimum Design Loads and Associated Criterial for Buildings and Other Structures (ASCE/SEI 7‐16), a first‐of‐its‐kind ASCE/SEI Manual of Practice 138: Structural Fire Engineering, has been developed to provide structural engineers a baseline level of guidance to practice structural fire engineering. Also, ASCE/SEI has partnered with the Charles Pankow Foundation to conduct an ambitious project meant to showcase this new technology to the industry. Advancing the adoption of performance‐based structural fire engineering within the AEC industry will benefit public safety while delivering more efficient and economic building designs.</p>
8
Paulin, Mike, Duane DeGeer, Joseph Cocker, and Mark Flynn. "Arctic Offshore Pipeline Design and Installation Challenges." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23117.
Повний текст джерелаАнотація:
With the oil industry’s continued quest for oil and gas in frontier offshore locations, several developments have taken place in regions characterized by seasonal ice cover including the US Beaufort, North Caspian, and Sakhalin Island. In these projects, pipeline systems have been used, which are a cost-effective, safe, and reliable mode of hydrocarbon transport. For pipeline development in Arctic, several years of data need to be collected to support the pipeline design and construction planning, and may be required by regulations. Therefore, Arctic offshore pipeline projects generally require repetitive mapping surveys and geotechnical programs to verify design loads, soil properties, and thaw settlement potential. The major design loads that are considered for Arctic projects include ice gouging, strudel scour, upheaval buckling as well as thaw settlement. These issues can have a significant influence on the pipeline engineering considerations such as strain based design, target burial depth requirements, cost, and safety. While important to the design of the pipeline, these issues account for just a few of the many criteria that must be considered when routing a pipeline; criteria which can be categorized as either engineering, environmental, social, administrative, or infrastructural. The pipelines which are currently operational in the Arctic are located in shallow water depths and close to shore but were influenced by the unique Arctic environmental loading conditions. The experience from these past projects provides a significant base for the design, and operating of future offshore arctic pipelines. Pushing the limits to developments further offshore in deeper water will require that additional consideration be given to aspects related to pipeline design, in particular with respect to burial for protection against ice gouging.
9
Bian, Zheyong, Nathalie Carchi, and Xiang Liu. "A Literature Review on Railroad Tank Car Thermal Protection Systems." In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8099.
Повний текст джерелаАнотація:
Abstract Railroad tank car transportation is the most efficient way to transport large amounts of hazardous material. More than 2 million tank-car loads of hazardous materials (hazmat) are transported annually by rail in the United States. Recently, the boom in the production of petroleum crude oil and natural gases from shale has dramatically increased the rail transport volume of flammable energy resources. However, accidents do occur, and the transportation of flammable hazardous material can result in disastrous consequences. The fire can heat up a tank car, rapidly increasing the inside pressure and causing the tank car to either rupture or explode. Railroad companies are developing or seeking advanced thermal protection systems to prevent tank car explosion or prolong the burst time to win a sufficient rescue time. It is of great importance to understand the existing thermal protection systems used in hazmat tank cars and to identify key priorities that the government and industry consider for improving tank car thermal protection performance, providing guidance for future thermal protection material development. Thus, this paper reviews the literature on the effects and analysis of different tank car thermal protection systems, identifying the effectiveness of different thermal protection components, properties of thermal protection materials, and testing methodologies. Different combinations of insulators and jackets are tested in order to observe the effects of the fire on the tank car. The tank car is tested while carrying hazardous material like liquefied petroleum gas, propane, and ethylene oxide, etc. This investigation analyzes the differences of thermal protection systems in prolonging the life span of a tank car engulfed in flames. A tank car can use either material like fiberglass, ceramic fiber blankets, perlite powder, or urethane foam to better insulate and thermally protect the tank car. An insulator is shown to prolong the life span of a tank car since bare tank cars tend to heat up rapidly when exposed to flames. The thermal protection system of a tank car is built of insulators, jackets, and supporting material for the insulator. The supporting material and jacket combination with the insulator also prevent the tank car from heating up rapidly. There are two primary testing methods, pool fire, and torch fire. Each type of fire has different outcomes and limits in which the tank car can withstand. When testing the heating of a tank car, thermocouples were placed throughout a tank car and recorded to check what areas were heated the most during the experiment. Some factors that had been accounted for in the previous studies were the wind speed and the direction of the wind, which affected the overall experiment, mostly torch fire experiments.
10
Christensen, Erik Damgaard, Stefan Carstensen, Mikael Thyge Madsen, Peter Allerød Hesselbjerg, and Christel Jeanty Nielsen. "Pore Pressure Under a Gravity Based Structure Under the Influence of Waves." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62585.
Повний текст джерелаАнотація:
The total wave load on a gravity based foundation for offshore wind turbines is influenced by the pore pressure from beneath the structure. The pore pressure is induced by the wave-structure-seabed interaction. Often the uplift force is included in a simplified way in the design of the gravity based foundation. This leads typically to very conservative designs in order to accommodate the uncertainties in the procedure. The experiments shall lead to better prediction models based on for instance CFD model’s with the direct calculation of pressure variations in the seabed and any erosion protection layer. Herewith, it will be possible to get a direct assessment of wave loads on the foundation, also under the seabed level. The study includes experiments as well as numerical analyses. A good agreement between the experimental results and the numerical analyses was found. In the numerical analyses, it was possible to investigate the effect of air content in the pores, which turned out to have an effect on the distribution of the pore pressure.