WorldWideScience

Sample records for capsizing

  1. Crisis control: Preventing chaos-induced capsizing of a ship

    Science.gov (United States)

    Ding, Mingzhou; Ott, Edward; Grebogi, Celso

    1994-11-01

    Responses of many man-made systems, such as ships or oil-drilling platforms, when subject to irregularly time varying environments, can be described by irregularly driven dynamical systems. Consequently, failures of such systems (e.g., capsize of a ship or collapse of a platform), under increasingly severe environmental conditions, come about when the system state escapes from a destroyed chaotic attractor located in some favorable region of the phase space. In this paper we propose a control strategy, based on a previous method of chaos control, which can prevent such failures from taking place. The key feature of our strategy is the incorporation of prediction of the evolution of the environment. This makes possible effective operation of the control even when the temporal behavior of the environment has substantial irregularity. We illustrate the ideas using ship capsizing as an example.

  2. CALCULATION ON THE UPRIGHTING PROCESS OF A CAPSIZED SHIP

    Directory of Open Access Journals (Sweden)

    De-wei Pan

    2016-08-01

    Full Text Available The processes of marine salvage require firstly the uprighting of the capsized ship, essentially bringing the deck to point up. Analysis and computation are the keys for the success in the application of the design schemes. Up to date, there are few researches on calculation methods for uprighting process of capsized ships at China and abroad. Researches about the effect of flooding quantity and the variation of the longitudinal strength during the uprighting process of capsized and damaged ships are even rarer. In this paper, hydromechanical equations to describe the effect of flooding are established and a calculation method for the longitudinal strength is introduced with reference to the hydrostatic theory for ships. Three typical uprighting processes are summarized according to the methods of treatment of damaged compartment. The stability of the inverted ship is calculated and analyzed using the General Hydrostatics software(GHS. Reserve buoyancy, shear forces, bending moments and torques are calculated in nine positions along the ship.

  3. An attempt to define critical wave and wind scenarios leading to capsize in beam sea

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Choi, Ju-hyuck; Kristensen, Hans Otto Holmegaard;

    2016-01-01

    Reliability Method (FORM) to define possible combined criti-cal wave and wind scenarios leading to capsize and corre-sponding probability of capsize. The FORM results for a fictitious vessel are compared with Monte Carlo simulation and good agreement is found at a much lesser computational effort. Finally...

  4. An attempt to define critical wave and wind scenarios leading to capsize in beam sea

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Choi, Ju-hyuck; Kristensen, Hans Otto Holmegaard;

    2016-01-01

    Reliability Method to define possible combined critical wave and wind scenarios leading to capsize and corresponding probability of capsize. The results for a fictitious vessel are compared with Monte Carlo simulation and good agreement is found at a much lesser computational effort. Finally, the results...

  5. Global Geometric Analysis of Ship Rolling and Capsizing in Random Waves

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The nonlinear biased ship rolling motion and capsizing in random waves are studied by utilizing a global geometric method. Thompson's α-parameterized family of restoring functions is adopted in the vessel equation of motion for the representation of bias. To take into account the presence of randomness in the excitation and the response, a stochastic Melnikov method is developed and a mean-square criterion is obtained to provide an upper bound on the domain of the potential chaotic rolling motion. This criterion can be used to predict the qualitative nature of the invariant manifolds which represent the boundary between safe and unsafe initial conditions, and how these depend on system parameters of the specific ship model. Phase space transport theory and lobe dynamics are used to demonstrate how motions starting from initial conditions inside the regions bounded by the intersected manifolds will evolve and how unexpected capsizing can occur.

  6. Is ENSO related to 2015 Easter Star Capsized on the Yangtze River of China?

    Science.gov (United States)

    Xie, P.

    2015-12-01

    Natural disasters have profound effects on community security and economic damage of China's Hubei province. In June 1st, 2015, a cruise ship, Easter Star, capsized on Yangtze River in Hubei province with 442 died. What reason gives rise to such strong convection causing ship sunk? Based on the wind disasters of Hubei province happened in 1963-2015, this study analyzes their features bytime-series regression, and correlates them to global El Niño/Southern Oscillation (ENSO) events. The compared results demonstrated that the wind disasters shown an increasing tendency. There are two peaks corresponding to the strongest ENSO peaks during the past 50 years; each peak lasts two-three years. The facts demonstrated an essential linear relation between the ENSO phenomena and wind disasters in Hubei province. 2015 Easter Star capsized happened at current El Niño event in 2014-2015. We also observed that the historical wind disasters appeared in seasonal variation. Over 90% events concentrated in spring and summer; very few events happened in autumn and winter. Moreover, the disasters depend on the geographic conditions. Most disasters concentrated in four zones, named as Xingshan-Baokang, Xuanen, Wufeng-Yichang, Jingzhou-Gongan, in which Xingshan and Changyang are the two most density of zones. Yangtze River provides an air flowing conduct for strong convective winds. It can be concluded that the strong convection causing 2015 Easter Star capsized is related to current global ENSO phenomenon.Keywords: ENSO, wind disaster, time-series regression analysis, Easter Star, Yangtze River, Hubei Province,

  7. Analytical method of capsizing probability in the time domain for ships in the random beam seas

    Institute of Scientific and Technical Information of China (English)

    LIU Liqin; TANG Yougang; LI Hongxia

    2007-01-01

    The methods for constructing safe basins of ships and predicting their survival probability in random waves were studied.The nonlinear differential equation of the rolling motion of ships in random beam seas was established considering nonlinear damping,nonlinear restoring moment,and random waves.The random rolling differential equation was solved in the time domain by applying the harmonic acceleration method and by synthetically considering the instantaneous state of ships and the narrowband wave energy spectrum.The numerical simulation of random capsizing course was brought forward,the safe basins were constructed for safe navigation,and the survival probabilities of ships were calculated.As an example,the safe basins on the rolling initial value plane were constructed for a 30.27-meter-long fishing vessel according to different initial conditions and random wave parameters.The survival probabilities of the fishing vessel under different significant wave heights were predicted.Thus,the survival probabilities of ships in random seas can be predicted quantitatively by the proposed method.

  8. CAPSIZE: A personal computer program and cross-section library for determining the shielding requirements, size, and capacity of shipping casks subject to various proposed objectives

    International Nuclear Information System (INIS)

    A new interactive program called CAPSIZE has been written for the IBM-PC to rapidly determine the likely impact that proposed design objectives might have on the size and capacity of spent fuel shipping casks designed to meet those objectives. Given the burnup of the spent fuel, its cooling time, the thickness of the internal basket walls, the desired external dose rate, and the nominal weight limit of the loaded cask, the CAPSIZE program will determine the maximum number of PWR fuel assemblies that may be shipped in a lead-, steel-, or uranium-shielded cask meeting those objectives. The necessary neutron and gamma shield thicknesses are determined by the program in such a way as to meet the specified external dose rate while simultaneously minimizing the overall weight of the loaded cask. The one-group cross-section library used in the CAPSIZE program has been distilled from the intermediate results of several hundred 1-D multigroaup discrete ordinates calculations for different types of casks. Neutron and gamma source terms, as well as the decay heat terms, are based on ORIGEN-S analyses of PWR fuel assemblies having exposures of 10, 20, 30, 40, 50, and 60 gigawatt days per metric tonne of initial heavy metal (GWD/MTIHM). In each case, values have been tabulated at 17 different decay times between 120 days and 25 years. Other features of the CAPSIZE program include a steady-state heat transfer calculation which will minimize the size and weight of external cooling fins, if and when such fins are required. Comparisons with previously reported results show that the CAPSIZE program can generally estimate the necessary neutron and gamma shield thicknesses to within 0.16 in. and 0.08 in., respectively. The corresponding cask weights have generally been found to be within 1000 lbs of previously reported results. 13 refs., 20 figs., 54 tabs

  9. CAPSIZE: A personal computer program and cross-section library for determining the shielding requirements, size, and capacity of shipping casks subject to various proposed objectives

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    1987-05-01

    A new interactive program called CAPSIZE has been written for the IBM-PC to rapidly determine the likely impact that proposed design objectives might have on the size and capacity of spent fuel shipping casks designed to meet those objectives. Given the burnup of the spent fuel, its cooling time, the thickness of the internal basket walls, the desired external dose rate, and the nominal weight limit of the loaded cask, the CAPSIZE program will determine the maximum number of PWR fuel assemblies that may be shipped in a lead-, steel-, or uranium-shielded cask meeting those objectives. The necessary neutron and gamma shield thicknesses are determined by the program in such a way as to meet the specified external dose rate while simultaneously minimizing the overall weight of the loaded cask. The one-group cross-section library used in the CAPSIZE program has been distilled from the intermediate results of several hundred 1-D multigroaup discrete ordinates calculations for different types of casks. Neutron and gamma source terms, as well as the decay heat terms, are based on ORIGEN-S analyses of PWR fuel assemblies having exposures of 10, 20, 30, 40, 50, and 60 gigawatt days per metric tonne of initial heavy metal (GWD/MTIHM). In each case, values have been tabulated at 17 different decay times between 120 days and 25 years. Other features of the CAPSIZE program include a steady-state heat transfer calculation which will minimize the size and weight of external cooling fins, if and when such fins are required. Comparisons with previously reported results show that the CAPSIZE program can generally estimate the necessary neutron and gamma shield thicknesses to within 0.16 in. and 0.08 in., respectively. The corresponding cask weights have generally been found to be within 1000 lbs of previously reported results. 13 refs., 20 figs., 54 tabs.

  10. 水下爆炸及随机外力下破损舰船的倾覆概率分析%Study of capsizing probability of the damaged warship subjected to underwater explosions and random excitations

    Institute of Scientific and Technical Information of China (English)

    张婧; 施兴华

    2011-01-01

    The calculation of capsizing probability of damaged warship subjected to underwater explosions and random excitations was discussed.The nonlinear differential equation of ship's roll motion under the conditions of underwater explosions and random excitations was established,in which the effect of underwater explosions and average wind disturbing moment were considered as constant heeling moments. Using the method of extended dimension number, the roll equation was transformed to five dimension Ito stochastic differential equation.Probability density function of rolling angle changed with time was presented based on Ganss-Legendre path integration method,when the random disturbance was reduced to white noise. And the expression of capsizing probability of warship was obtained on the basis of the existent capsizing criterion.An example for calculating the capsizing probability of damaged warship subjected to weapon attack with different blasting charge at different time was given and the effect of blasting charge on capsizing probability was analyzed.The study shows that this method could easily predict rolling capsizing probability of damaged warship subjected to underwater explosions and random excitations quantitatively. It is helpful to further research of capsizing and stability.%探讨了水下爆炸载荷和随机风浪联合作用下破损舰船的运动及其倾覆概率的计算.将爆炸载荷作用及平均风扰动力矩处理为定常横倾力矩,建立了爆炸载荷和随机风浪中舰船运动的非线性微分方程.结合扩维技巧,将横摇方程转化为五维Ito随机微分方程,应用Gauss-Legendre路径积分法给出随机扰动为白噪声时横摇角度的概率密度函数随时间的演变,按照现有的倾覆准则给出预报一定装药量下舰船倾覆概率的表达式.通过算例,计算了破损舰船不同装药量下不同时刻的倾覆概率,分析不同装药量对倾覆概率的影响.研究表明,此方法简便可

  11. MARKET WATCH

    Institute of Scientific and Technical Information of China (English)

    HU YUE

    2010-01-01

    @@ TO THE POINT: Chinese fund management companies spilled red ink in the first half of 2010 as the stock market turned bearish. The shipbuilding industry regains its lost ground but unsteady seas could capsize hopes for continued success.

  12. A Dynamic Model for Roll Motion of Ships due to Flooding

    DEFF Research Database (Denmark)

    Xia, Jinzhu; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    1999-01-01

    Because of the large undivided deck spaces, RoRo vessels are often sensitive to rapid capsizing due to sudden ingress of water. Following a high-energy damage, a rapidly increasing heeling moment is induced by the ingress of water, which generates a roll motion of the damaged vessel. If......, additionally, the car deck is flooded and/or the cargo is shifted, the heeling moment may exceed the residual restoring moment, which results in capsizing....

  13. Wind estimation around the shipwreck of Oriental Star based on field damage surveys and radar observations

    OpenAIRE

    Meng, Zhiyong; Yao, Dan; Bai, Lanqiang; Zheng, Yongguang; Xue, Ming; Zhang, Xiaoling; Zhao, Kun; Tian, Fuyou; Wang, Mingjun

    2016-01-01

    Based on observational analyses and on-site ground and aerial damage surveys, this work aims to reveal the weather phenomena—especially the wind situation—when Oriental Star capsized in the Yangtze River on June 1, 2015. Results demonstrate that the cruise ship capsized when it encountered strong winds at speeds of at least 31 m s−1 near the apex of a bow echo embedded in a squall line. As suggested by the fallen trees within a 2-km radius around the wreck location, such strong winds were lik...

  14. 33 CFR 62.65 - Procedure for reporting defects and discrepancies.

    Science.gov (United States)

    2010-07-01

    ... missing, sunk, capsized, damaged, off station, or showing characteristics other than those advertised in... discrepancies: (1) Radio messages should be prefixed “Coast Guard” and transmitted directly to a Government shore radio station listed in Chapter three of Radio Navigation Aids Publication, 117, for relay to...

  15. Nonlinear Container Ship Model for the Study of Parametric Roll Resonance

    DEFF Research Database (Denmark)

    Holden, Christian; Galeazzi, Roberto; Rodríguez, Claudio;

    2007-01-01

    Parametric roll is a critical phenomenon for ships, whose onset may cause roll oscillations up to 40, leading to very dangerous situations and possibly capsizing. Container ships have been shown to be particularly prone to parametric roll resonance when they are sailing in moderate to heavy head ...

  16. The dynamic performance of narrow actively tilting vehicles

    NARCIS (Netherlands)

    Pauwelussen, J.P.

    2000-01-01

    The major advantage of a motorcycle with respect to a passenger car is the possibility of the driver to tilt during cornering and thereby maintaining stability whereas a passenger car will suffer from the risk of capsizing at high speed. This observation has motivated recently various manufacturers

  17. Numerical modelling of iceberg calving force responsible for glacial earthquakes

    Science.gov (United States)

    Sergeant, Amandine; Yastrebov, Vladislav; Castelnau, Olivier; Mangeney, Anne; Stutzmann, Eleonore; Montagner, Jean-Paul

    2016-04-01

    Glacial earthquakes is a class of seismic events of magnitude up to 5, occurring primarily in Greenland, in the margins of large marine-terminated glaciers with near-grounded termini. They are caused by calving of cubic-kilometer scale unstable icebergs which penetrate the full-glacier thickness and, driven by the buoyancy forces, capsize against the calving front. These phenomena produce seismic energy including surface waves with dominant energy between 10-150 s of period whose seismogenic source is compatible with the contact force exerted on the terminus by the iceberg while it capsizes. A reverse motion and posterior rebound of the terminus have also been measured and associated with the fluctuation of this contact force. Using a finite element model of iceberg and glacier terminus coupled with simplified fluid-structure interaction model, we simulate calving and capsize of icebergs. Contact and frictional forces are measured on the terminus and compared with laboratory experiments. We also study the influence of geometric factors on the force history, amplitude and duration at the laboratory and field scales. We show first insights into the force and the generated seismic waves exploring different scenarios for iceberg capsizing.

  18. Elements of Risk Analysis for Collision and Grounding of a RoRo Passenger Ferry

    DEFF Research Database (Denmark)

    Otto, S.; Pedersen, Preben Terndrup; Samuelidis, M.;

    2002-01-01

    Newly developed software was applied to study the effects of damages due to collision and grounding. The annual risk of collision and grounding was computed for an example RoRo passenger ferry. Collision frequency was evaluated for a specified route taking into account traffic data. Grounding...... reputation was not considered. It was shown that the main part of the calculated annual risk is caused by capsize of the vessel after severe damage....

  19. Accidents of surface effect ships and hydrofoil craft

    Energy Technology Data Exchange (ETDEWEB)

    Korotkin, I.M.

    1981-01-01

    The work describes 200 accidents and disasters of hovercraft and hydrofoil craft of the United States, Great Britain, France, and other fleets which occurred in the 1960s and 1970s as a result of capsizing, storm damage, collisions, fires, explosions, etc. The causes of the accidents, the functioning of various craft systems, and the actions of the crews are examined. Recommendations on the prevention of such accidents are discussed.

  20. The effect of tyre and rider properties on the stability of a bicycle

    OpenAIRE

    Bulsink, V.E.; Doria, A.; Belt, van de, M.; Koopman, H.F.J.M.

    2015-01-01

    To work towards an advanced model of the bicycle-rider-environment system, an open-loop bicycle-rider model was developed in the commercial multibody dynamics software ADAMS. The main contribution of this article to bicycle dynamics is the analysis of tyre and rider properties that influence bicycle stability. A system identification method is used to extract linear stability properties from time domain analysis. The weave and capsize eigenmodes of the bicycle-rider system are analysed. The e...

  1. Fuzzy Reasoning as a Base for Collision Avoidance Decision Support System

    OpenAIRE

    brcko, tanja; Švetak, Jelenko

    2013-01-01

    Despite the generally high qualifications of seafarers, many maritime accidents are caused by human error; such accidents include capsizing, collision, and fire, and often result in pollution. Enough concern has been generated that researchers around the world have developed the study of the human factor into an independent scientific discipline. A great deal of progress has been made, particularly in the area of artificial intelligence. But since total autonomy is not yet expedient, the deci...

  2. ACSNI study group on human factors

    International Nuclear Information System (INIS)

    Organisational failures are now recognised as being as important as mechanical failures or individual human errors in causing major accidents such as the capsize of the Herald of Free Enterprise or the Pipa Alpha disaster. The Human Factors Study Group of the Advisory Committee on the Safety of Nuclear Installations was set up to look at the part played by human factors in nuclear risk and its reduction. The third report of the Study Group considers the role played by organisational factors and management in promoting nuclear safety. Actions to review and promote a safety culture are suggested. Three main conclusions are drawn and several recommendations made. (UK)

  3. MARKET WATCH

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chinese fund management companies spilled red ink in the first half of 2010 as the stock market turned bearish. The shipbuilding industry regains its lost ground but unsteady seas could capsize hopes for continued success. Chinese property developers’ financing woes are inten- sifying. China Mobile reported modest growth in first-half profits as compe- tition heats up among the telecom giants. Outbound M&A deals, especially those involving natural resources, by Chinese companies in the first half of this year hit a record high. China aims to lift its installed hydropower capac- ity to 300 million kilowatts by 2015 from the current 200 million kilowatts.

  4. Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland

    Science.gov (United States)

    Walter, Fabian; Amundson, Jason M.; O'Neel, Shad; Truffer, Martin; Fahnestock, Mark; Fricker, Helen A.

    2012-01-01

    We investigated seismic signals generated during a large-scale, multiple iceberg calving event that occurred at Jakobshavn Isbræ, Greenland, on 21 August 2009. The event was recorded by a high-rate time-lapse camera and five broadband seismic stations located within a few hundred kilometers of the terminus. During the event two full-glacier-thickness icebergs calved from the grounded (or nearly grounded) terminus and immediately capsized; the second iceberg to calve was two to three times smaller than the first. The individual calving and capsize events were well-correlated with the radiation of low-frequency seismic signals (forces acting at the glacier terminus. The signals therefore appear to be local manifestations of glacial earthquakes, although the magnitudes of the signals (twice-time integrated force histories) were considerably smaller than previously reported glacial earthquakes. We thus speculate that such earthquakes may be a common, if not pervasive, feature of all full-glacier-thickness calving events from grounded termini. Finally, a key result from our study is that waveform inversions performed on low-frequency, calving-generated seismic signals may have only limited ability to quantitatively estimate mass losses from calving. In particular, the choice of source time function has little impact on the inversion but dramatically changes the earthquake magnitude. Accordingly, in our analysis, it is unclear whether the smaller or larger of the two calving icebergs generated a larger seismic signal.

  5. The Applicability of Hydrofoils as a Ship Control Device

    Institute of Scientific and Technical Information of China (English)

    Md. Shamim Mahmud

    2015-01-01

    Centrifugal forces are commonly created when ships turn, which may cause a ship to capsize in a critical situation. A mathematical model has been developed to optimize the stability coefficients for ship, with the aim to prevent capsizing and to increase ship maneuverability in high-speed water craft. This model can be used to develop algorithms for control system improvement. The mathematical model presented in this paper optimized the use of multipurpose hydrofoils to reduce heeling and the trimming moment, maintaining an upright ship’s position and lessening the resistance via transverse force. Conventionally, the trimming and heeling of a ship are controlled using ballast water;however, under variable sea conditions it is sometimes difficult to control a ship’s motion using ballast water. In this case, a hydrofoil would be more stable and maneuverable than a ballast tank controlled vessel. A movable hydrofoil could theoretically be adapted from moveable aerofoil technology. This study proves the merit of further investigation into this possibility.

  6. Reliability Analysis of Dynamic Stability in Waves

    DEFF Research Database (Denmark)

    Søborg, Anders Veldt

    2004-01-01

    the distribution of the exceedance probability may be established by an estimation of the out-crossing rate of the "safe set" defined by the utility function. This out-crossing rate will be established using the so-called Madsen's Formula. A bi-product of this analysis is a set of short wave time series...... accidents in the past. The rules therefore only leaves little room for evaluation and improvement of safety of a ship's dynamic stability. A few studies have evaluated the probability of ship stability loss in waves using Monte Carlo simulations. However, since this probability may be in the order of 10......-4 per ship year such brute force Monte-Carlo simulations are not always feasible due to the required computational resources. Previous studies of dynamic stability of ships in waves typically focused on the capsizing event. In this study the objective is to establish a procedure that can identify...

  7. Sottotitolazione intralinguistica e inglese ‘lingua franca’: strategie di mediazione audiovisiva

    Directory of Open Access Journals (Sweden)

    Pietro Luigi Iaia

    2016-01-01

    Full Text Available Abstract – This chapter illustrates the results of a workshop held at the University of Salento, during an English-Italian Translation Course. A group of undergraduate students was asked to produce an intralingual translation for the subtitles of the video Capsized in Lampedusa – Fortress Italia, which deals with the situation in Lampedusa after a boat capsized in October 2013. The original video – available on YouTube – is subtitled into English for Vice News and, in a ‘role play’ exercise (Rosnow 1990, students were commissioned to adopt a type of English that could be directed at a wider international audience also including non-native English speakers. The contrastive analysis of the original and reformulated versions is designed to enquire into the influence and actualisation of the commissioner’s requests in the lexical, structural and functional features of target texts. The extent will also be explored, to which the type of English adopted in the alternative subtitles can be defined as a lingua-franca variation (Seidlhofer 2011, due to the inclusion of specific verb tenses and the selection of simplified syntactic structures (Seidlhofer 2004, aimed at facilitating the audience’s reception and accessibility to the semantic dimensions of the text. Finally, the analysis will also highlight the translators’ attempts to respect the temporal and spatial constraints of subtitles (Neves 2009, as well as the multimodal construction (Kress and van Leeuwen 2006 of audiovisual texts, which result in the use of condensation strategies (Gottlieb 2005; Pedersen 2011, thus proposing the new definition of audiovisual mediation.

  8. Nonlinear Container Ship Model for the Study of Parametric Roll Resonance

    Directory of Open Access Journals (Sweden)

    Christian Holden

    2007-10-01

    Full Text Available Parametric roll is a critical phenomenon for ships, whose onset may cause roll oscillations up to +-40 degrees, leading to very dangerous situations and possibly capsizing. Container ships have been shown to be particularly prone to parametric roll resonance when they are sailing in moderate to heavy head seas. A Matlab/Simulink parametric roll benchmark model for a large container ship has been implemented and validated against a wide set of experimental data. The model is a part of a Matlab/Simulink Toolbox (MSS, 2007. The benchmark implements a 3rd-order nonlinear model where the dynamics of roll is strongly coupled with the heave and pitch dynamics. The implemented model has shown good accuracy in predicting the container ship motions, both in the vertical plane and in the transversal one. Parametric roll has been reproduced for all the data sets in which it happened, and the model provides realistic results which are in good agreement with the model tank experiments.

  9. YACHTING CLUB

    CERN Multimedia

    YACHTING CLUB

    2010-01-01

    INTERNAL RAGATTE - BEST EVER ! If you missed Internal Regatta III on Sunday 11 July, you missed one of the best we can recall! The winds were about perfect, fairly stable Bf 2 with periodic gusts higher and the resulting capsizes to keep crews concentrating. It was extremely hot but we ran the usual three heats for keelboats and a record four for dinghies, catamarans - where there was another record, surely: a total of 11 boats in that class, of which three privately owned by members. And a final record: we calculate five boats were competing in their first-ever regatta. Results on the webpage. Surprisingly for those who remember regattas of a couple of years back, only three keelboats competed, so there would have been plenty of scope for less experienced members to come along regardless and probably find themselves a place. It is also noteworthy that the keelboat winner was Andrea Messina with an - ummm, may I say - less experienced crew himself! We hope this win bodes well for his forthcoming Transl&am...

  10. YACHTING CLUB

    CERN Multimedia

    YACHTING CLUB

    2010-01-01

    The Dinghy weekend A recent full weekend was run for dinghies: thanks to dedicated help from regular dinghy sailors and teachers, a lot of people overcame their uncertainty or lack of knowledge about dinghies, getting wet, what the gennaker actually does (and why it’s different from a spinnaker), and had good fun. Our trusty Surveillance boat put in a lot of hours (and petrol!) ensuring no-one came to any harm, thanks Christian (pictured) and Rob. It has to be admitted, winds were not, errr, challenging, for most of that weekend: we old salts know that as soon as the weather gets hot, winds abandon us until the autumn. That is a slight exaggeration but remains fact-based - like the old chestnut that if Mont Blanc is wearing a hat of clouds, it’ll rain soon! It was still wet-suit weather, for safety and because voluntary capsizes were on the programme - until you have done a few, you do not overcome a natural fear of them and they are an integral part of sailing a small dinghy compe...

  11. 风雨联合作用下高速列车受力数值模拟%Simulation of the action effect of wind-driven rain on high-speed train

    Institute of Scientific and Technical Information of China (English)

    敬俊娥; 高广军

    2013-01-01

    k-ε double equation turbulent model and discrete phase model were used in the research of the effect of different rainfall intensities,different wind speeds and different train velocityies on the flow field around the vehicle.The results show that the rain drops under the effect of cross wind crash on to the surface of the carriage and then splash,which change the roughness and smoothness of the surface of the carriage,So it leads to that the side force,lift force and capsizing moment increase gradually with the increase of wind speed,train speed and rainfall intensity.The dynamic load on train when bearing strong wind and rainfall is a little bigger than that when bearing only strong wind load.%采用双方程湍流模型和离散相模型相结合的方法,对不同降雨强度、横风风速和车速下高速运动车辆周围的流场进行研究.研究结果表明:在横风作用下,下落的雨滴与高速运行的列车发生碰撞,雨滴飞溅、改变了车身表面的粗糙度和不平整性,导致车辆运行横向力、升力和倾覆力矩均随着车速、风速和降雨强度的增大逐渐变大;伴随着降雨过程的强横风作用,车辆所受的气动载荷与强横风的单独作用情况下相比稍微增加.

  12. ON THE EVALUATION OF DEFLECTIONS OF THE VERTICAL USING FFT TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There exist three types of convolution formulae for the efficientevaluation of gravity field convolution integrals,i.e.,the planar 2D convolution,the spherical 2D convolution and the spherical 1D convolution.The largest drawback of both the planar and the spherical 2D FFT methods is that,due to the approximations in the kernel function,only inexact results can be achieved.Apparently,the reason is the meridian convergence at higher latitudes.As the meridians converge,the Δφ,Δλ blocks do not form a rectangular grid,as is assumed in 2D FFT methods.It should be pointed out that the meridian convergence not only leads to an approximation error in the kernel function,but also causes an approximation error during the implementation of 2D FFT in computer.In order to meet the increasing need for precise determination of the vertical deflections,this paper derives a more precise planar 2D FFT formula for the computation of the vertical deflections.After having made a detailed comparison between the planar and the spherical 2D FFT formulae,we find out the main source of errors causing the loss in accuracy by applying the conventional spherical 2D FFT method.And then,a modified spherical 2D FFT formula for the computation of the vertical deflections is developed in this paper.A series of numerical tests have been carried out to illustrate the improvement made upon the old spherical 2D FFT.The second part of this paper is to discuss the influences of the spherical harmonic reference field,the limited capsize,and the singular integral on the computation of the vertical deflections.The results of the vertical deflections over China by applying the spherical 1D FFT formula with different integration radii have been compared to the astro-observed vertical deflections in the South China Sea to obtain a set of optimum deflection computation parameters.

  13. 固定平台桩腿强度分析

    Institute of Scientific and Technical Information of China (English)

    王榕

    2015-01-01

    浅海采油主要借助于海洋固定平台,平台强度直接关系着操作人员的生命安全.平台的倾覆或倒塌均可能导致生命丧失和海洋环境的污染,给国家经济和海洋环境带来不利的影响.桩腿是承受海洋平台重量和外部载荷的重要支撑部分,桩腿强度是否满足规范要求对平台的安全有着重要的现实意义.以埕岛油田某中心平台为例,对风、浪、流、冰载等载荷进行组合分析,计算分析和比较灌浆桩腿和非灌浆桩腿强度对平台安全的影响.%Shallow sea oil recovery mainly relies on offshore fixed platform and the platform strength is directly related to the life safety of the operators.The collapse or capsizing of the platform may cause the loss of life and the pollution of the marine environment, which will have a negative impact on the national economy and the marine environment. Spud legs are the major supporting components of the platform to bear the weight of the offshore platform itself as well as external loads. Whether the spud leg strength meets the requirements as specified in the relevant rules and regulations has an important practical significance to the platform safety. Taking the central platform in Cheng Dao oil field as the example, a combined analysis of the wind, wave, current and ice loads is carried out; calculation analysis and comparison of the strength and influences to the platform safety are made between of the grouted spud pile and the non grouted pile leg.

  14. The City Image of Dostoevsky's Petersburg%陀思妥耶夫斯基笔下的彼得堡城市意象

    Institute of Scientific and Technical Information of China (English)

    傅星寰; 张一莹

    2015-01-01

    陀思妥耶夫斯基笔下的彼得堡城市意象——阴郁之花、神幻之城、罪恶之都、呼求悔改的"尼尼微",传达和推进了他的"彼得堡文本"的主题——"人之谜"的情感哲思、对俄罗斯现代性地批判、给予俄罗斯以及俄罗斯人未来道路选择的箴言,统摄着他的"彼得堡文本"的氛围和基调,形成了他富有特殊魅力的艺术表现.这些融入作家感怀的城市意象,源于现实又超越于现实之上,饱含了作家的文化批判及预言性质的深刻洞见.这些意象最终指向彼得堡的救赎之路,陀氏看到了传统观念终将经受洪水而倾覆的彼得堡有在信仰中被赎救的可能,从而藉着他的"彼得堡文本",给予彼得堡传统末日神话一个新的出路,盼望彼得堡成为响应呼召悔改后"新生"的城市.%The city image of Dostoevsky's Petersburg —Dark flowers,Magic City,Sin City,Call for repen-tance's 'Nineveh',communicated and promoted his "Petersburg text" theme—the emotion philosophy a-bout "mystery of the people",the modernity criticism of Russia,the proverbs given to choose the future path of Russia and the Russian,controlled his "Petersburg text" atmosphere and tone,and formed the special charm of artistic expression.These city images,which reflect the writer's lament and sentiment, come from life and beyond the reality,and fully reflect the writer's profound insight of cultural criticism and prophetic nature.These images finally point to the redemption road of Petersburg.Dostoevsky per-ceived that the traditional Petersburg would be capsized by flood finally,and there was possible to be saved in faith.Thereby,Dostoevsky created a new way for traditional doomsday myth of Petersburg via his"Pe-tersburg text",and hoped that Petersburg would become a"new city",which responses to calling for the repentance.

  15. Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars.

    Science.gov (United States)

    Gallagher, C.; Balme, M. R.

    2012-04-01

    role in at least one mode of catena formation [2]. As well as presenting the morphological evidence for a genetic association between TPT and pit catenas, we present corroborative evidence that fluvial channel networks on Mars have in places increased in complexity through the linking of pits arranged in linear to arcuate arrays, culminating in a pseudo-branching channel network. Such systems do not occur at topographic margins and did not disintegrate into stepped crustal blocks. However, the scale of these channels and the volumes of liquid intermittently impounded in craters along these channel systems indicate that pit chains are associated with significant excess groundwater production leading to channelized flow, including catastrophic discharges when crater-impounded lakes along-flow were breached. Are the MDB and Isidis cone chains exhumed pit catenas and are the pits the surface expression of more deep-seated conduits? Do pit catenas indicate excess pore-water production, sufficient to link individual pits and dissect crustal blocks? Together, do these assemblages reflect the degradation of the MDB and Isidis margins and the subsequent stripping of adjacent low-lying plains? The crucial observations presented in this research (cone chains lying between crustal blocks, together with the morphometric similarities) are consistent with the interpretation of the cones and catenas having a common origin. Consequently, we hypothesise that the translated, back-rotated, tilted and capsized disposition of en echelon blocks is very reminiscent of the morphology produced during lateral spreading [3] associated with stratabound liquefaction below a low-gradient, rigid, insensitive surface. Significantly, such liquefaction events cause extensive, arcuate ground fractures along with the discharge of sediment-laden groundwater from the liquefiable substratum to the surface through pipes and conical boils confined within inter-block fractures. These conduits and their

  16. 包裹式加筋土挡土墙抗震试验分析%Seismic Tests and Analysis of Warped Reinforced Earth-retaining Wall

    Institute of Scientific and Technical Information of China (English)

    李庆海; 王炳锟; 蒋楚生; 段忠臣

    2012-01-01

    Research purposes: According to the engineering features of the Xiangyun Station of Guangtong-Dali Railway, the research was done on the reinforcing mechanism, load bearing, deformation, design methods, computing theory and the failure mode of the wraped reinforced earth-retaining wall under earthquake effect to improve the computing theory and numerical simulation method for the seismic design of the reinforced earth-retaining wall and promote the application of reinforced earth-retaining wall in engineering. Research conclusions; The warped reinforced earth-retaining wall is better than the ordinary earth-retaining wall in seismic property because the wrapped effect can make seismic wave weak during the propagation and amplification of the seismic wave along the wall up. When in 0. 4 g and 0. 616 g , the model produced the evident seismic fall, and cracks happened in the junctions between the wall panel and the reinforced soil and between the reinforced soil and the unreinforced soil. In the peak acceleration, the potential fracture surface of these two kinds of experimental models were distributed in the same position, approximate to 0.45 H vertical line. But in the "Code for Design of Retaining Structure of Railway Subgrade" (TB 10025-2006) , the potential fracture surface is approximate to 0.3 H vertical line and it slants to unsafety. So the reinforcing length should be increased in design. From the theoretical calculation and the analysis results of the internal and external stability of the reinforced earth-retaining wall obtained by the test data calculation, it was seen the coefficient of sliding resistance, the coefficient of capsizing resistance, the coefficient of uplifting resistance of the whole wall and the coefficient of uplifting resistance of the geogrid in various layers obtained by theoretical calculation were larger than the test data calculation. This showed the current code was unsafe and could be properly modified.%研究目的:针对广