본 논문은 슬로싱 상태에 놓인 포화 상태 액체수소탱크에서 열 유속 및 BOG(Boil-off gas)의 경향을 다루고 있다. 특히, 액체-기체 간의 침투 및 혼합에 의한 열 교환에 관심을 두었다. 먼저, VOF(Volume of fluid)와 Eulerian 기반의 다상 유동모델로 모형 슬로싱 실험 을 모사하여 압력을 예측하고 계측된 값과 비교하였다. 자유 수면 및 충격 압력 실험 결과와 해석 결과를 비교하였으며, 유체의 속도 예측에서 정확할 수 있음을 간접적으로 증명하였다. 그리고 2차원의 Type-C 원통형 수소탱크를 대상으로 다상열유동해석을 수행하 였다. 이때 포화상태에 놓인 액체 및 기체수소를 가정하고, 해석을 통해 각 상간의 혼합에 의한 열 교환의 수준을 확인하고자 하였다. 단, 상간의 열 교환만을 관심으로 두고 있었으므로 질량전달 및 기화모델은 해석에서 제외하였다. 최종적으로 상의 혼합으로 인해 액 체수소로 유입되는 열 유속의 기여도에 대하여 정리하였다. 또한 액체수소로 유입되는 열 유속과 집중 질량 기반의 간이식을 통해 BOG 발생량 및 경향을 예측하고 분석하였다.
This study aims at classifying and interpreting on the shrine forest vegetation located in Jirisan national park affiliated to an ecotone in southern part of Korea, foreseeing a vegetation change based on composition species and dominant species on canopy, and proposing the direction of vegetation management. The shrine forests were classified into the 7 community units as Chamaecyparis obtusa-Cryptomeria japonica afforestation, Pinus densiflora community, Pinus rigida afforestation, Quercus variabilis-Quercus serrata community, Zelkova serrata-Kerria japonica for. japonica community, Phyllostachys bambusoides forest, Camellia japonica community. This research is also expatiated on the analogous results of ordination analysis with phytosociological analysis. The constituents of deciduous broad-leaved forest in the warm temperate zone were appeared in the most vegetations. It emerged less that the constituents of evergreen broad-leaved forest in the warm-temperate zone and deciduous broad-leaved forest in the cold-temperature zone. The life form analyses were made use with the two ways: appearance species in total communities and each community. The species diversity of shrine forests is declined because the high dominances of Sasa borealis and Pseudosasa japonica emerged in the shrub and herb layers. These shrine forests will be succession to Q. variabilis-Q. serrata community as the representative vegetation of deciduous broad-leaved forest in the warm-temperate zone, owing to the temperature rise by global warming, and an evergreen broad-leaved forest will be able to be also formed if a temperate rise will be continued. The one of the artificial management of shrine forests is to consider the introduction of the constituents of evergreen broad-leaved forest in the warm-temperate zone.
This study aims at classifying and interpreting on the vegetation structure and the vegetation transition over 25 years (between 1986 and 2010), and the correlation with the change of some conditions (the vegetation height and coverage on each layer and the climate factors as WI, CI, mean annual temperature, mean annual total precipitation etc.) in the Evergreen Broad-Leaved Forest,, Hong-Do island. The EBLF is classified into five units of vegetation (Hedera rhombea-Machilus thunbergii community (M-M comm.), Castanopsis sieboldii forest (Machilus japonica-Castanopsis sieboldii community; Raphiolepis indica var. umbellata-C. sieboldii community), community (Qa comm.), Carpinus turczaninovii community (Ct comm.), Camellia japonica stand (Cj stand)). The vegetation transition by CCA had high correlation with the height and coverage on each layer and the climate factors, and it did the succession (transition) that the M-M comm. (2010) from Mallotus japonicus community・Machilus thunbergii community・Carpinus coreana community (Cc comm.)・Aucuba japonica community (Aj comm.)・Trachelos permum asiaticum var. intermedium-Quercus acuta community (TQ comm.) (1986), the communities of C. sieboldii forest (2010) from Aj comm.・TQ comm.・Raphiolepis umbellata-Camellia japonica community (RC comm.) (1986), the Qa comm. (2010) from Ardisia japonica-Castanopsis sieboldii community (AC comm.) and TQ comm. (1986), the Ct comm. (2010) from Cc comm.・RC comm.・Aj comm.・Quercus serrata community and the Cj stand (2010) from AC comm. (1986). the height and coverage on each layer are also changed.
This study aims at classifying and interpreting on the vegetation structure, the correlation between a vegetation and an environment, a species diversity and a life-form of Evergreen Broad-Leaved Forest(EBLF) located in Gageo-do Island. It is also the objective that the estimation of vegetation change founded on the species composition and characteristics. The vegetation of EBLF was classified into three forests or four community units as Machilus thunbergii forest (Polystichum polyblepharon-M. thunbergii community and Phaenosperma globosum-M. thunbergii community), Ilex integra-Castanopsis sieboldii community, Quercus acuta community and Neolitsea sericea stand. The ordination analysis by DCA is analogous with the vegetation structure analysis. As a result of the correlation (Pearson's correlation coefficient) with environmental conditions, the Altitude has the significance with the distribution of communities. The total vegetation change by progress of succession will not be wandered away from the present vegetation structure practically, and the vegetation on the underlayers will be a little changed.
This study aims at classifying and analyzing the vegetation structure of Castanopsis sieboldii forest, one of the evergreen broad-leaved forests found under the warm-temperate climate of Korea. It is also compared with the ones of the Castanopsis sieboldii forest in Japan where most similar such forest of Korea, to find unique vegetation structures of the only Korean forest. Vegetation structure of Korean Castanopsis sieboldii forest was divided into two units at the level of community units both of Ardisia japonica-Castanopsis sieboldii community and Ardisio-Castanopsietum sieboldii association. The association carries similar type with the vegetation system of Japan, but any subunits differentiated with the Japan were found vary much. Hierarchical cluster analysis brings in similar result with the analysis on the vegetation structure as well.
This study aims at classifying and interpreting on the vegetation structure and analyzing the correlationship between communities and environmental conditions in Mt. Wolchulsan. We also predicted the succession possibility and the vertical distribution change of vegetations according to the global warming, through the pioneer species of a forest change and dominant species of canopy vegetations. We also analyzed the Raunkiaer's life-form. The communities in this ecotone are distributed vertically in the order of a Quercus acuta community, a Q. serrata-Q. variabilis community and a Q. serrata community. A Pinus densiflora community appears on the most of altitudes. The distribution of communities correlates highly with an altitude. The Q. serrata-Q. variabilis community will be succession to the Q. acuta community, and the Q. variabilis will be under natural selection gradually or remain locally. The Q. serrata community will possibly maintain as it is, and the P. densiflora community will be also under natural selection gradually. The valuable quantitative and numerical life-forms are confirmed and the layer structure of present vegetation will not be changed.