사석구조물(捨石構造物)의 안정성(安定性)에 관한 수리모형(水理模型)의 축척효과(縮尺?果)

류청로,Ryu, Cheong Ro 대한토목학회 1987 대한토목학회논문집 Vol.7 No.3

Scale effects of stability, run-up, run-down and reflection of layered coastal structures are investigated through the experiments with 7 kinds of hydraulic scale models. The occurrence mechanism and the control method of scale effects are also discussed. As a result, it is found that the similarity of permeability of inner layers plays an important role in the occurrence of scale effects, which has been neglected in the most of conventional model tests. To assure the best scale effects for permeable coastal structures, control of Reynolds numbers of the porous media flow in each layer is recommended. It is also found that Reynolds numbers in revetment, filter, and core layer must be greater than $2{\times}10^4$, $3{\times}10^3$, and $1{\times}10^3$, respectively. 해안구조물(海岸構造物)의 안정성(安定性)과 사면상(斜面上)의 반사파(反射波), run-up, run-down 등 흐름특성(特性)에 대한 모형(模型)의 축척효과(縮尺?果) 발생(發生) 메카니즘과 그 제어(制御) 방법(方法)을 7종(種)의 축척모형(縮尺模型)에 의해 실험적(實驗的)으로 연구(硏究)하였다. 그 결과(結果), 종래(從來)의 많은 연구자(硏究者)들이 소홀히 해 왔던 구조물(構造物) 내부(內部)의 침투류(浸透流) 특성(特性)의 상사(相似) 여부(如否)가 축척효과(縮尺?果) 발생(發生)의 가장 중요(重要)한 요인(要因)임을 지적(指摘)하였다. 해안구조물(海岸構造物) 가운데서 특히 투과성(透過性) 구조물(構造物)의 축척효과(縮尺?果) 제어(制御)를 위해서는 피복층(被覆層), filter층(層), 피복층(被覆層)에 가까운 core부(部)의 침투류(浸透流) Reynolds수(數)가 각각(各各) Re > $2{\times}10^4$, $Re_f$ > $3{\times}10^3$, $Re_c$ > $1{\times}10^3$인 조건(條件)을 만족하도록 구조물(構造物) 각(各) 층(層)의 축척(縮尺)을 결정(決定)하는 것이 바람직함을 강조(强調)하였다.

부산 송도해수욕장과 해안공학의 뉴 패러다임

류청로,Ryu, Cheong-Ro 한국해안해양공학회 2013 해안과 해양 Vol.6 No.2

생태계 제어 시설물의 설계 및 배치 최적화 ( 1 ) 연승식 양식시설의 계류력 특성 및 동요저감에 관한 연구

류청로,김현주 ( Cheong Ro Ryu,Hyeon Ju Kim ) 한국수산과학회 1995 한국수산과학회지 Vol.28 No.1

To develop the optimal design method for the longline type scallop culturing facilities in the open sea, numerical calculations and hydraulic model experiments are carried out for the stability and function optimization. Using the results for the motion and tension of the facilities, stable design concepts and effects of motion control system by vertical anchor and resistance discs are discussed. The results of this study that can be applied to the design are as follows: 1) Total external forces by design wave(H_(⅓)=6.7m, T_(⅓)=12sec) at the coastal waters of Jumunjin for unit facility (one main line) are estimated to 5-20 tons, and required anchor weights are 10-40 tons in the case of 2-point mooring system. Though the present facilities are stable to steady currents, but is unstable to the extreme wave condition of return period of 10 years. 2) The dimensions and depth of array systems must be designed considering the ecological environments as well as the physical characteristics including the mooring and holding forces that are proportional to the length and relative depth of main line to wave length, and the number of buoys and nets. 3) Oscillation of the facility is influenced by water particle motion and the weight of hanging net, and is excited at both edge, especially at the lee side. To reduce the motion of the nets, the vertical anchoring system and the resistence disc method are recommended by the experimental results. 4) The damage of rope near the anchor by abrasion should be prevented using the ring-type connection parts or anchor chains.

A New Design Method of Rubble Mound Structures with Stability and Wave Control Consideration

류청로,Ryu, Cheong Ro Korean Society of Civil Engeneers 1987 대한토목학회논문집 Vol.7 No.3

구조물(構造物)의 안정성(安定性)과 파랑제어기능(波浪制御機能)을 고려(考慮)한 새로운 사석구조물(捨石構造物) 설계법(設計法)을 제안(提案)하였다. 이 설계법(設計法)은 임의의 파랑조건하(波浪條件下)에서 파랑(波浪)의 반사(反射) 및 run-up을 저감(低減)시키고, 안정성(安定性)을 증대(增大)시키는 설계개념(設計槪念)을 가졌다. 설계식(設計式)은 허용파괴율(許容破壞率)과 안정성(安定性)에 대한 파군특성(波群特性)의 영향(影響) 도입(導入)하여 유도하였으며, 이에는 해안파(海岸波)의 평균(平均) run-sum이라는 새로운 외력개념(外力槪念)이 사용(使用)되었다. 마지막으로 이 새로운 설계법(設計法)에 의한 일양단면(一樣斷面)과 복합단면(複合斷面) 사석구조물(捨石構造物) 설계예(設計例)로부터 이 설계법(設計法)의 유용성(有用性)과 이점(利點)을 검증(檢證)하였다. A new design method of rubble mound structures that includes the considerations of stability and wave control is proposed. Using the method, design of structures that reduce the wave reflection and run-up and increase the rubble stability is assured under the given wave conditions. The new design formula is developed so that the allowable prcentage of damage and the wave grouping effects on rubble stability are also considered in design. For this a new definition of the mean run-sum is made. Finally, the new method is applied for the design of uniform and composite slope rubble mound structures and the significant advantages are found.

The Tidal Water-Exchange Estimation Method based on Particle Tracking Model

Cheong-Ro Ryu(류청로),Jong-Kyu Kim(김종규),Dong-Guan Seol(설동관) 한국해양공학회 1998 韓國海洋工學會誌 Vol.12 No.4

외해와 연결된 입구를 통한 내만의 해수교환율을 파악하는 것은 내만의 수질을 관리하는 데 있어서 매우 중요하다. 본 연구에서는 마산만을 대상표로 수치적 입자추적모델을 이용하여 해수교환율의 조령에 따른 변화 및 만내의 공간적 특성 즉 지역에 따른 변화를 검토하면서 내만의 해수교환율 산정상의 문제를 논의하고, 조류에 의한 내만의 해수교환율 산정방법에 대해 정리하였다. 조령 및 조시에 따라 시시각각 산정된 해수교환율로부터 선형회귀식을 구하고, 그로부터 내만에 유입된 오염물질의 체류시간을 추정하였다. 이러한 결과를 기존의 현장관측된 결과와 비교함으로써 모델의 유용성을 검증하였다. 이 모델에 의해 계산한 해수교환율은 소조기에는 3~12 % 정도의 비율을 나타내었고, 대조기에는 20~30 % 정도의 교환율을 보여 조령에 따라 상이한 결과를 나타내었다. 구역별로 실시한 입자추적의 결과로부터 유속이 빠른 만 중앙부의 체류시간은 38일, 그리고 만내부와 외해와 연결되는 업구구역에서는 60~63일로 나타났다.

생태계 제어 시설물의 설계 및 배치 최적화 ( 2 ) - 흐름장에서의 인공어초의 침하 및 매몰 특성 -

류청로(Cheong Ro Ryu),김현주(Hyeon Ju Kim),이한수(Han Su Lee),신동일(Dong Il Shin) 한국수산과학회 1997 한국수산과학회지 Vol.30 No.1

Sediment transport around artificial habitat which is induced by the change of flow due to installation of the structure plays a role not only as a defect function of subsidence and burial but also bottom-environment control function. This study examined the characteristics of local scouring and deposition with sediment sizes, current velocities and installation direction of artificial habitat in flow field. Resultant subsidence and burial processes are investigated and discussed with Reynolds number. Together with sediment number and dimensionless time elapse, prediction formulas are established by combining these relationships. Bottom control function as cultivating effects is discussed with installation direction, and applicability of countermeasures is compared and stone pavement method is recommended.

한국 동남해역에서의 유출유 확산예측모델

류청로(Cheong Ro Ryu),김종규(Jong Kyu Kim),설동관(Dong Guan Seol),강동욱(Dong Uk Kang) 한국해양환경·에너지학회 1998 한국해양환경·에너지학회지 Vol.1 No.2

연안해역의 기상 파랑관측망 설계 및 해석기술의 구축 - 해양파랑관측자료의 해석방법 -

류청로(Cheong Ro Ryu),김희준(Hee Joon Kim),손병규(Byung Kyu Shon) 한국수산과학회 1997 한국수산과학회지 Vol.30 No.1

Application of digital filter to the wave analysis is studied using the observed data by wave gauge. Sea wave data obtained from wave gauge always include long wave frequency components. In order to estimate the sea wave parameters, we must re-analyzed wave data by using a digital filter and the concept of mean sea level correction method. By the wave by wave analysis and spectral methods, sea wave parameters on the basis of wave data obtained by the conventional method and digital filter are compared. The best-fitted design filter determined by the necessary conditions of frequency responses, can be obtained by calculating various transfer functions. Thus, to get the best the digital filter design, both Butterworth filter and Savitzky-Golay filter of digital filter are used in the frequency and time domain, respectively. Three cases of observation wave data are calculated by applying digital filter. The components of different frequency bands in the surf zone are coexisted in three cases. The wave data for wind wave components is computed using the digital filter in the surf cone and off-surf zone, and based on the filtered data, wave parameters are calculated by the spectral analysis and wave by wave analysis methods, respectively. As a results, when sea wave data observed by wave gauge are analyzed, the Savitzky-Golay method is recommended which can well appear cut-off frequency by experimental choosing filter length in the time domain. The better mean sea level correction method is the Butterworth filter in the frequency domain.

유류확산모델 개발 및 동해의 유류오염 사고대책

류청로(CHEONG-RO RYU),김홍진(HONG-JIN KIM) 한국해양공학회 2005 韓國海洋工學會誌 Vol.19 No.4

There has been increasing offshore oil exploration, drilling, and production activities, as well as a huge amount of petroleum being transported by tankers and pipelines through the ocean and costal environment. Assessment must be made of the potential risk of damage resulting from the exploration, development and transportation activities. This is achieved through predictive impact evaluations of the fate of hypothetical or real oil spills. When an oil spill occurs, planning and execution of cleanup measures also require the capability to forecast the short-term and long-term behavior of the spilled oil. A great amount of effort has been spent by government agencies, oil industries, and researchers over the past decade to develop more realistic models for oil spills. Numerous oil spill models have been developed and applied, most of which attempt to predict the oil spill fate and behavior. For an actual contingency planning, the oil fate and behavior model should be combined with an oil spill incident model, an environmental impact and risk model and a contingency planning model. The purpose of this review study is to give an overview of existing oil spill models that deal with the physical, chemical, biological, and socio-economical aspects of the incident, fate, and environmental impact of oil spills. After reviewing the existing models, future research needs are suggested. In the study, available oil spill models are separated into oil spill incident, oil spill fate and behavior, environmental impact and risk, and contingency planning models. The processes of the oil spill fate and behavior are reviewed in detail and the characteristics of existing oil spill fate and behavior models are examined and classified so that an ideal model may be identified. Finally, future research needs are discussed.

해수순환모델에 대한 최적화 방법

김종규,류청로,장선덕 ( Jong Kyu Kim,Cheong Ro Ryu,Sun Duck Chang ) 한국수산과학회 1994 한국수산과학회지 Vol.27 No.6

It has been demonstrated for the finite-difference ocean circulation model that the problem of uncertain forcing and input data can be tackled with an optimization techniques. The uncertainty problem in interesting flow properties is exploring a finite difference ocean circulation model due to the uncertainty in the driving boundary conditions. The mathematical procedure is based upon optimization method by the conjugate gradient method using the simulated data and a simple barotropic model. An example for the ocean circulation model is discussed in which wind forcing and the steady-state circulation are determined from a simulated stream function.