Bird screen meshes are installed at the air inlet and outlet ducts of spent fuel storage casks to inhibit the intrusion of debris from the external environment. The presence of these screens introduces an additional resistance to air flow through the ducts. In this study, a porous media model was developed to simplify the bird screen meshes. CFD analyses were used to derive and verify the flow resistance factors for the porous media model. Thermal analyses were carried out for concrete storage cask using the porous media model. Thermal tests were performed for concrete casks with bird screen meshes. The measured temperatures were compared with the analysis results for the porous model. The analysis results agreed well with the test results. The analysis temperatures were slightly higher than the test temperatures. Therefore, the reliability and conservatism of the analysis results for the porous model have been verified.
In th process of the way music service changing from download to streaming with the improvement of internet technology, digital sound transmission was regulated as a sub-concept of public transmission that is separated with transmission and broadcasting through copyright law revision in 2006. While the scale of digital sound transmission copyrights collecting is steadliy increasing the rate of its settlement distribution is not, as it is applied to the field of bankground music in shop service way of internet streaming. The purpose of this thesis is to examine the reason why the rate of digital sound transmission settlement distribution is not increasing in the same league as the increasing rate of its copyrights collecting and to propose an improvement for the rate of increasing its settlement distribution.
본 연구에서는 저장볼트(storage vault)의 실험을 위하여 1/4 축소모델 내 튜브의 적정 발열량을 선정하고자 상사해석을 수 행하였다. 저장볼트에 대한 열 및 유동 해석을 우선적으로 수행하였고, 크기를 1/4로 축소한 저장볼트에 대하여 동일한 전 산해석을 수행하였다. 전산해석 결과를 바탕으로, 제안된 무차원수를 비교하여 원형모델과 온도분포와 유동분포가 유사하 게 되는 발열량을 선정하였다. 1/4 축소 저장볼트 내 튜브의 열유속이 1.3배일 때, 원형 저장볼트와 1/4 축소 저장볼트의 온 도장 및 유동장이 상사되었다. 이 때, 1/4 축소 저장볼트 내 발열량은 약 190 W이다.