• Title/Summary/Keyword: Local circulation

Search Result 311, Processing Time 0.026 seconds

The Role of Local Circulation for the Improvement on Urban Thermal Environment (도시 열환경 개선을 위한 국지순환풍의 역할에 관한 연구)

  • Park, Myong-Hee;Jung, Woo-Sik;Kim, Hae-Dong
    • Journal of Environmental Science International
    • /
    • v.19 no.10
    • /
    • pp.1257-1269
    • /
    • 2010
  • In this study the AWS was installed in three areas to analyze creation and characteristics of local wind circulation through observation. According to the result, in night time when mountain wind is well developed showed temperature in A area located in Dalbigol valley and B area adjacent with the valley was lower than C area located in the lowland of the center of city by $1.5\sim4^{\circ}C$. The wind speed was also shown two times stronger than C area. In addition, in terms of wind direction, A and B areas showed east wind consistently according to topographic shapes of Dalbigol valley with high altitude and residential sites of lowland with low altitude. Although the C area didn't show big changes in wind direction due to the effects of city structures, east wind is often seen so mountain wind from Dalbigol valley is found to have an effect at least. Through the analysis of temperature, wind speed, and wind direction, nigh time showed relatively cold mountain wind blew following Dalbigol valley, throughout residential sites and to the center of city with lowland. During the daytime, the temperature in the city with lowland and residential sites is constantly higher than A area located in Dalbigol valley, and strong wind speed following Dalbigol valley, and three areas have $200\sim300^{\circ}$ of main wind direction, so west valley wind throughout the city with lowland and following Dalbigol is clearly formed.

Numerical Simulation on the Wind Ventilation Lane and Air Pollutants Transport due to Local Circulation Winds in Daegu Districts (대구지역의 국지순환풍의 환기경로 및 대기오염수송에 관한 수치모의)

  • Koo, Hyun-Suk;Kim, Hae-Dong
    • Journal of the Korean earth science society
    • /
    • v.25 no.6
    • /
    • pp.418-427
    • /
    • 2004
  • Recently, urban planning with consideration of urban climate, represented by the concept of urban ventilation lane is widely practiced in many countries. The concept of urban ventilation lane is mainly aimed to improve the thermal comfort within urban area in summer season. It has also the aim to reduce the urban air pollution by natural cold air drainage flows which are to be intensified by a suitable alignment of buildings as well as use zonings based on scientific reasons. In this study, the prevailing wind ventilation lane of a local wind circulation and around Daegu for a typical summer days was investigated by using a numerical simulation. The transport of air pollutants by the local circulation winds was also investigated by using the numerical simulation model, the RAMS (Reasonal Atmospheric Model System).The domain of interest is the vicinity of Daegu metropolitan city (about 900 km2). The horizontal scale of the area is about 30 km. The simulations were conducted under a late spring synoptic condition with weak gradient wind and almost clear sky. From the numerical experiment, the following three conclusions were obtained: (1) The major wind passages of the local circulation wind generated by radiative cooling over the representative mountains of Daegu (Mt. Palgong and Mt. Ap) were found. The winds blow down along the valley axis over the eastern part of Daegu as a gravity flow during nighttime. (2) At the flatland, the winds blow toward the western part of Daegu through the city center. (3) As the results, the air pollutants were transported toward the western part of Daegu by the winds during nighttime.

LOCALLY ENRICHED QUADTREE GRID NUMERICAL MODEL FOR NEARSHORE CIRCULATION IN THE SURF ZONE

  • Park, Koo-Yong
    • Water Engineering Research
    • /
    • v.1 no.3
    • /
    • pp.187-197
    • /
    • 2000
  • This paper describes an adaptive quadtree-based 2DH wave-current interaction model which is able to predict wave breaking, shoaling, refraction, diffraction, wave-current interaction, set-up and set-down, mixing processes (turbulent diffusion), bottom frictional effects, and movement of the land-water interface at the shoreline. The wave period-and depth-averaged governing equations are discretised explictly by means of an Adams-Bashforth second-order finite difference technaique on adaptive hierarchical staggered quadtree grids. Grid adaptation is achieved through seeding points distributed according to flow criteria(e.g. local current gradients). Results are presented for nearshore circulation at a sinusoidal beach. Enrichment permits refined modelling of important localised flow features.

  • PDF

The Improvement of Circulation System in Theme Park - Focused on the EXPO Ocean Park in Yeosu - (주제공원의 동선 개선 제안 - 여수 엑스포 해양공원을 대상으로 -)

  • Park, Hyo-Chul;Han, Hye-Sun
    • Korean Institute of Interior Design Journal
    • /
    • v.23 no.5
    • /
    • pp.202-210
    • /
    • 2014
  • The EXPO Ocean Park in Yeosu has taken on the apsect of a theme park and has specialized facilities. But the outdoor circulation system that has been used by Expo 2012 Yeosu Korea still remained. These conditions can occur unused circulation and a long walk between facilities. The Purpose of this study is to suggest the improvement of circulation system that uses walking and outdoor space at the Expo Ocean Park in Yeosu. The following researches are drawn based upon the purpose. First, Definition and existing academic literature of theme park is considered. Second, the type, utilization condition, and circulation of outdoor facilities of Expo Ocean Park are investigated through the field survey and analysis. The field survey is conducted on the Expo Ocean Park in Yeosu for five times from October. 2013 to March. 2014. The data is collected through the photographed outdoor park and interviewing the staff of 2012 Yeosu World Expo Foundation. Third, the case study on outdoor circulation of waterside park and park with amusement facilities that are similar to Expo Ocean Park are examined. The result of this study is expected to seek sustainable management of Expo Ocean Park for maximizing local resident and visitors' satisfaction and improving effective park image. Since the field survey was conducted before the park is reopened and The Expo Ocean Park is on the improve through the this study at present, the verification of improvement scheme based on Post-Occupancy Evaluation(POE) is needed for future study.

Effect of the Wind on the Pollutant Transport in Masan Bay (마산만의 오염물질 수송에 미치는 바람 효과)

  • Kim, Jong-Hwa;Lee, Mun-Ok;Gang, Ju-Bok
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.28 no.4
    • /
    • pp.385-397
    • /
    • 1992
  • Current measurements at 3 sections and numerical experiments were carried out in Masan Bay to understand the effect of the wind on the residual currents and pollutant transport. The vertical distribution of horizontal velocities were directly affected by the wind at the depths of 1m and 2m beneath the sea surface. Analysis of the velocity data suggested that changes in the vertical gravitational circulation contributed to the net circulation. The net transport of water through the northern part of the bay was observed to be landward, with wind-induced transport of about 100m super(3)/s. Hence, wind is concluded to be the dominant mechanism driving the net circulation in the northern area of Masan Bay. Numerical experiments are shown that when S wind with 5m/s blew, northern area of the bay was generated the horizontal circulation of clockwise and local gyre. On the contrary of those, N wind made her to the anti-clockwise. In the case of no wind, the tidal residual current(constant flow) is very small or neglected except the bay-mouth. The inflow or outflow pattern of the mouth is considered as the flows generated by tidal residual current only. The distance of wind-induced transport of pollutant was as long as 2 times of no wind during the one tidal period.

  • PDF

A Seasonal Circulation in the East China Sea and the Yellow Sea and its Possible Cause

  • Oh, Kyung-Hee;Pang, Ig-Chan
    • Journal of the korean society of oceanography
    • /
    • v.35 no.4
    • /
    • pp.161-169
    • /
    • 2000
  • A seasonal circulation in the East China Sea and the Yellow Sea and its possible cause have been studied with CSK data during 1965-1989. Water mass distributions are clear in winter, but not in summer because the upper layer waters are quite influenced by atmosphere. To solve the problem, a water mass analysis by mixing ratio is used for the lower layer waters. The results show that the distribution of Tsushima Warm Current Water expands to the Yellow Sea in winter and retreats to the East China Sea in summer. It means that there is a very slow seasonal circulation between the East China Sea and the Yellow Sea: Tsushima Warm Current Water flows into the Yellow Sea in winter and coastal water flows out of the Yellow Sea in summer. By the circulation, the front between Tsushima Warm Current Water and coastal water moves toward the shelf break in summer so that the flow is faster in the deeper region. The process eventually makes the transport in the Korea Strait increase. The Kuroshio does not seem to influence the process. A possible mechanism of the process is the seasonal change of sea surface slope due to different local effects of surface heating and diluting between the East China Sea and the Yellow Sea.

  • PDF

A Study on the Application of Natural Circulation -based Green Village Landscape Design-: The Case of Joongchon Village in Gimje-si (자원순환형 녹색마을 경관디자인 적용에 관한 연구 -김제시 중촌마을을 대상으로-)

  • Kim, Sang-Bum;Son, Ho-Gi;Lee, Chang-Hun;Rhee, Sang-Young
    • Journal of Agricultural Extension & Community Development
    • /
    • v.18 no.4
    • /
    • pp.961-981
    • /
    • 2011
  • This study selected Joongchon Village in Gimje-si as a target, in order to apply green village design regarding regional circumstances and features within the local government, in making green village as an efficient scheme in aspect of locality for 'Low Carbon, Green Growth'. Subsequently, we conducted survey and analysis. Natural circulation-based green village of Joongchon Village in Gimje-si is a low carbon green village, based upon eco-friendly cattle shed. Even though it is the fact that the initial costs of an eco-friendly cattle shed are rather high, it is the long-term low carbon green technology that can transform livestock night soils into resources, provide them to agricultural farms, independently supply energies from by-product, and produce energies additionally. Therefore, Joongchon Village in Gimje-si is the good example of green village, applying the design which actively utilizes discharged by-product from cattle shed, so natural circulation and energy production are able as an eco-friendly green technology.

On Tidal Energy Horizontal Circulation

  • Nekrasov, A.V.
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1992.08a
    • /
    • pp.69-71
    • /
    • 1992
  • The local horizintal flux of tidal energy is characterized by the surface density $\omega$ = $\rho$ g h ζ u ($\rho$ - sea water density, g - gravitation, h - depth, ζ - tidal surface elevation, u - vertically averaged tidal current velocity vector). In general the flux vector $\omega$ comprises active and reactive components whose relation determines the local structure of a tidal wave.(omitted)

  • PDF

Numerical Simulation of Ozone Concentration using the Local Wind Model in Pusan Coastal Area, Korea (부산연안역에서 국지풍모델을 이용한 오존농도의 수치모의)

  • Jeon, Byung-Il;kim, Yoo-Keun;Lee, Hwa-Woon
    • Journal of Environmental Science International
    • /
    • v.6 no.4
    • /
    • pp.335-350
    • /
    • 1997
  • Numerical simulations of photochemical air pollution (CBM: Carbon-Bond Mechanisms under a theoretical three-dimensional local wind system are carried to clarify the fundamental characteristics of the effects of local wind on photochemical air pollution. According to the AWS data of Pusan coastal area and KMA, the surface wind of Pusan during summertime showed a very remarkable land and sea breeze circulation. The ozone concentration distribution using local wind model showed that high ozone concentration zone near coastal area moved toward inland In the afternoon. This change implies a sea breeze Increases the ozone concentration, but a land breeze decreases it in Pusan coastal area.

  • PDF

A Study on the Book Circulation Rules of Public Library in Korea (전국 공공도서관 대출규정 조사 연구)

  • Yoon, Hee-Yoon
    • Journal of Korean Library and Information Science Society
    • /
    • v.51 no.1
    • /
    • pp.349-372
    • /
    • 2020
  • Regardless of East and West, public libraries provide various services to their communities based on collections. The decisive reason for local residents to visit public libraries is to access and borro w collections. An important condition maintenance to support these activities and services is the library circulation(usage) rules. Therefore, this study compared and analyzed the library membership, maximum loan items, loan period, loan reserve and renewal, overdue fines, disposal of lost and damaged items, loan of non-book materials, loan regulations for the disabled. And after checking the relative deviations in connection with the library cases of major developed countries, this study proposed the improvement of circulation rules. In order to minimize public complaints about circulation services and to relieve the burden of practitioners such as personnel disadvantage due to administrative audit for non-recoverable ite ms, public libraries must faithfully rearrange the circulation rules and regulations.