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现用辐射仪器采用PC-1500计算机进行数据处理,该机是一种比较落后的机型,内存容量小,易死机.当遇到停电时,程序需执行PS=1(暂停打印数据)功能,仪器正常采集数据,把数据存储起来而不打印.此时,PC-1500机若出现死机,重新启动程序后,以前采集的数据会全部丢失,因不能补测而造成记录缺测. 相似文献
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Numerical simulation of breaking wave generated sediment suspension and transport process based on CLSVOF algorithm 总被引：1，自引：0，他引：1
The sediment suspension and transport process under complex breaking wave situation is investigated using large eddy simulation （abbreviated as LES hereafter） method. The coupled level set （LS） and volume of fluid （VOF） method is used to accurately capture the evolution of air？water interface. The wall effect at the bottom is modeled based on the wave friction term while the complicate bottom boundary condition for sediment is tackled using Chou and Fringer’s sediment erosion and deposition flux method. A simulation is carried out to study the sediment suspension and transport process under periodic plunging breaking waves. The comparison between the results by CLSVOF method and those obtained by the LS method is given. It shows that the latter performs as well as the CLSVOF method in the pre-breaking weak-surface deformation situation. However, a serious mass conservation problem in the later stages of wave breaking makes it inappropriate for this study by use of the LS method and thus the CLSVOF method is suggested. The flow field and the distribution of suspended sediment concentration are then analyzed in detail. At the early stage of breaking, the sediment is mainly concentrated near the bottom area. During the wave breaking process, when the entrapped large-scale air bubble travels downward to approach the bottom, strong shear is induced and the sediment is highly entrained. 相似文献
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复杂边界下的流场数值模拟常基于非结构化网格进行求解,建立一种在非结构混合网格上求解水深平均的二维浅水方程的模型,以便精确模拟复杂边界、提高计算效率。该模型时间项离散采用隐格式使得模型具有较好的稳定性,对流项和扩散项分别采用总变差减小(Total Variation Diminishing,TVD)格式和构造辅助点的方法来离散,同时采用水深平均的标准k-ε模型来封闭湍流模型。选用两个经典验证算例检验模型,计算结果表明,基于非结构混合网格开发的模型具有较高的精度,且收敛性能较好。 相似文献
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现用辐射仪器采用ＰＣ— 15 0 0计算机进行数据处理 ,该机是一种比较落后的机型 ,内存容量小 ,易死机。当遇到停电时 ,程序需执行ＰＳ =1(暂停打印数据 )功能 ,仪器正常采集数据 ,把数据存储起来而不打印。此时 ,ＰＣ— 15 0 0机若出现死机 ,重新启动程序后 ,以前采集的数据会全部丢失 ,因不能补测而造成记录缺测。为避免此类现象发生 ,可在执行ＰＳ =1操作后 ,把每个正点时的屏显值抄录下来。有了屏显值 ,尽管ＰＣ— 15 0 0机内所存数据丢失 ,仍可计算每小时曝辐量和挑选极值。抄录虽繁琐 ,但在仪器更新之前却不失为一种好办法。辐射观测执… 相似文献
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