• Title/Summary/Keyword: External Wind

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The assessment of Safe Navigation Regarding Hydrodynamic forces between ships in Restricted Waterways

  • Lee, Chun-Ki;Yun, Jong-Hwui;Yoon, Jeom-Dong
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.143-149
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vesselsin restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transversedistance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the higher one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

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The Assessment of Safe Navigation Regarding Hydrodynamic forces between Ships in Restricted Waterways

  • Lee, Chun-Ki;Lee, Sam-Goo
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.2002-2009
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

The assessment of Safe Navigation Regarding Hydrodynamic forces between ships in Restricted Waterways

  • Lee, Chun-Ki;Yoon, Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.89-93
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

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A Bibliographic Study on The Research of nosebleeding by damaged lung (상폐(傷肺)에 의(依)한 비출혈(鼻出血)의 문헌적(文獻的) 고찰(考察))

  • Kim, Sung-Hyun
    • The Journal of Internal Korean Medicine
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    • v.12 no.1
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    • pp.45-55
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    • 1991
  • It has been known that the nosebleeding is a king hemorrhage occured to be damaged yang-rak (陽略) & lung. the results obtained were as follows; 1. The cause of nosebleeding were divided internal external, these were lung-heat(肺實熱), wind-heat(風熱), dry-heat(煥熱), wind-cold(風寒), summer-heat(暑熱), and those were transporting of Liver-fire(肝火犯肺), Liver-kidney-fire(肝腎陰虛熱傷肺), Stomach-fire(胃火熾盛), Heart-fire(心火千肺). 2. The treatment of external ; Chungpaesulyul(淸肺泄熱), Yanghyuljihyul(凉血止血), Sanpungchungyul(散風淸熱), Jaeumchungjo(滋陰淸煥). 3. The treatment of internal ; Chungkansahwa(淸肝瀉火), Yanghuljihyul(凉血止血), Jayumganghwa(滋陰降火), Chunguysahwa(淸胃瀉火). The cause of nosebleeding was almost heat (fire), and the treatment were Sanpyo(散表) & Chungri(淸裏).

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Literatural study of the cause and mechanism of Eye Disease (眼病의 病因 病機에 對한 文獻的 考察)

  • Gang, Seung-Won;No, Seok-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.5 no.1
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    • pp.27-44
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    • 1992
  • The cause and mechanism of eye diseases are follow in biblography. The etiological factor of eye diseases are nearly caused by heat. It is important to distinguish deficiency and substance. In external etiologic factors wind-fever is most of all in six exogenous factors. In internal etiologic factors xu(deficiency) of kidney, blood and fire of seven emotions are lots. In factors other than the internal and external, eating greasy food and hyper-caloric food are a lot of case. In relation with the yin-yang andxu-shi, ther are a lot of eye diseases symptom as dark-dizziness due to the yin-xu of hepatic-kidney. According to eight principles of differentiation of syndromes, syndromes of exterior, heat, shi, almost fall into the category of yang and syndromes of interior, cold, xu, nearly fall into the category of yin. In interior treatment, inducing wind and clearing heat, using Qi and tonifying blood, tonifying and suing of hepatic-kid ney are useful and often used treatment.

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Linearized analysis of the internal pressures for a two-compartment building with leakage

  • Yu, Xianfeng;Gu, Ming;Xie, Zhuangning
    • Wind and Structures
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    • v.28 no.2
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    • pp.89-97
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    • 2019
  • The non-linear equations governing wind-induced internal pressures for a two-compartment building with background leakage are linearized based on some reasonable assumptions. The explicit admittance functions for both building compartments are derived, and the equivalent damping coefficients of the coupling internal pressure system are iteratively obtained. The RMS values of the internal pressure coefficients calculated from the non-linear equations and linearized equations are compared. Results indicate that the linearized equations generally have good calculation precision when the porosity ratio is less than 20%. Parameters are analyzed on the explicit admittance functions. Results show that the peaks of the internal pressure in the compartment without an external opening (Compartment 2) are higher than that in the compartment with an external opening (Compartment 1) at lower Helmholtz frequency. By contrast, the resonance peak of the internal pressure in compartment 2 is lower than that in compartment 1 at higher Helmholtz frequencies.

A study on the average wind load characteristics and wind-induced responses of a super-large straight-cone steel cooling tower

  • Ke, S.T.;Du, L.Y.;Ge, Y.J.;Zhao, L.;Tamura, Y.
    • Wind and Structures
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    • v.25 no.5
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    • pp.433-457
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    • 2017
  • As a novel typical wind-sensitive structure, the wind load and wind-induced structural behaviors of super-large straight-cone cooling towers are in an urgent need to be addressed and studied. A super large straight-cone steel cooling tower (189 m high, the highest in Asia) that is under construction in Shanxi Power Plant in China was taken as an example, for which four finite element models corresponding to four structural types: the main drum; main drum + stiffening rings; main drum + stiffening rings + auxiliary rings (auxiliary rings are hinged with the main drum and the ground respectively); and main drum + stiffening rings + auxiliary rings (auxiliary rings are fixed onto the main drum and the ground respectively), were established to compare and analyze the dynamic properties and force transferring paths of different models. After that, CFD method was used to conduct numerical simulation of flow field and mean wind load around the cooling tower. Through field measurements and wind tunnel tests at home and abroad, the reliability of using CFD method for numerical simulation was confirmed. On the basis of this, the surface flow and trail characteristics of the tower at different heights were derived and the wind pressure distribution curves for the internal and external surfaces at different heights of the tower were studied. Finally, based on the calculation results of wind-induced responses of the four models, the effects of stiffening rings, auxiliary rings, and different connecting modes on the dynamic properties and wind-induced responses of the tower structure were derived and analyzed; meanwhile, the effect mechanism of internal suction on such kind of cooling tower was discussed. The study results could provide references to the structure selection and wind resistance design of such type of steel cooling towers.

A Study on Thermal Stability of the Non-insulated HTS Racetrack-type Coil Under Various External Pressures Applied to Straight Sections (무절연 고온 초전도 레이스트랙형 코일의 직선구간 압력변화에 따른 열적 안정성 연구)

  • Kwon, O.J.;Kim, K.L.;Choi, Y.H.;Yang, D.G.;Kim, Y.G.;Lee, T.S.;Ko, T.K.;Lee, H.G.
    • Progress in Superconductivity and Cryogenics
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    • v.14 no.3
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    • pp.33-37
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    • 2012
  • An HTS racetrack-type coil without turn-to-turn insulation was characterized by critical current, sudden discharge, and over-current tests with respect to external pressures applied to the straight sections of the coil. The thermal stability of the non-insulated HTS racetrack-type coil was remarkably enhanced with increasing external pressure applied to the straight sections of racetrack-type coil. Furthermore, over-current test results confirmed that the non-insulated HTS racetrack-type coil with increased turn-to-turn thermal contact has the potential to be manufactured into field coils of HTS wind turbine generators with highly enhanced thermal and electrical stabilities.

Load and Structural Analysis of an Offshore Wind-Turbine Foundation with Weight Control Functionality (자중조절 기능이 있는 해상풍력 지지구조의 하중 및 구조해석)

  • Oh, Minwoo;Kim, Donghyun;Kim, Kiha;Kim, Seoktae
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.3
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    • pp.453-460
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    • 2016
  • Offshore wind turbines are divided into an upper wind turbine and a lower support structure. Offshore wind turbine system is required to secure high reliability for a variety of external environmental conditions compared to ground wind turbines because of additional periodic loads due to ocean wave and current effects. In this study, extreme load analyses have been conducted for the designed offshore wind turbine foundation with weight control functionality using computational fluid dynamics (CFD) then structural analyses have been also conducted to investigate the structural design requirement.

The study of moving and dissipation of floating mines due to wind forced river plume (바람영향하의 River plume에 따른 부유물체 확산 및 이동 연구)

  • Baek, Seong-Ho;Park, Kyeong-Ju
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.295-298
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    • 2010
  • To find out moving and dissipation patterns of laid floating object estuary this paper has focused on forming, changing and variation of the wind forced river plume. In steady state(without external force), river can be form a bulge and downcoast alongshore current on gently sloped continental shelf. Under the downwelling wind and downcoast meanflow those river plume's patterns are similar with the steady state case except enhancement of downcoast transportation. Under the upwelling wind condition bulge linearly move to the northwest with 45 angle due to Ekman transport. It's moving speed are linear with the strength of the wind stress but moving paths are independent of that. So, in this case, floating object will be dissipate to outside as move to the upcoast.

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