引汉济渭秦岭隧洞高磨蚀性硬岩TBM滚刀磨损试验研究

引汉济渭工程秦岭输水隧洞TBM掘进施工在试掘进段因遭遇高磨蚀性硬岩地层,滚刀发生严重磨损,致使施工进度严重滞后。为降低刀具磨损,节约施工成本,加快施工进度,必须对刀具磨损进行准确预测。针对高磨蚀性地层,开展滚刀磨损预测研究; 通过课题组前期研究结果,建立滚刀磨损理论预测模型; 通过室内实验,建立滚刀磨损实验预测模型; 通过现场试验,对室内实验模型及课题组前期研究建立的理论预测模型进行验证。结果表明,实验预测结果具有较高的准确性,相对误差在10%以内。     

应用CFD方法改善发动机舱散热性能

针对某车型发动机舱怠速工况下温度过高的问题,运用软件Fluent对发动机舱内的气体流动进行三维仿真.从仿真结果的速度和温度分布,发现冷却气体回流是导致发动机舱过热的根本原因.据此提出添加阻风板的改进方案,以有效地改善该车型发动机舱内冷却气体的流动,解决了舱内温度过高的问题.     

基于设计空间探索的型线自动优化

船舶型线优化是改善船舶阻力性能、提高运行经济性的关键环节.文中将型线修改、阻力CFD模拟、设计空间探索优化等流程整合在一起,创建了一个型线"自动优化"的平台.在该平台上实现了对美国海军水面作战中心(Naval Surface Warfare Center)潜艇模型DTRC Model 5470艏部型线的自动优化,得出了一个阻力性能最优的艏部型线方案.经过模型拖曳试验验证,证明了该种"自动优化"方案的可行性与有效性.     

Reliability Evaluation Method Based on Double Beta Prior Distribution for the Pyrotechnic Device

On the basis of the Bayesian principle, a method of selecting the double beta distribution as a priori distribution is proposed for the system reliability evaluation when the available field test samples are small for pyrotechnic device. Under the condition of different field and historical data, the mean square error(MSE) and coverage ratio(CR) of the reliability evaluation are compared by numerical simulation when the conjugate distribution and uniform distribution are selected as the priori distribution. Finally, the rationality and engineering applicability of the proposed method are verified through an example of the reliability evaluation of a typical pyrotechnic device.