Exploration of hidden structure and prediction of gas anomaly area based on gas control projects [PDF]
The investigation of hidden structures and the prediction of gas abnormal area form the foundation of gas disaster prevention engineering. In accordance with the laws and regulations governing coal mining in our country, a gas pumping project must be ...
Hongqing CUI +3 more
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, 2018 采用CFD数值模拟方法开展了基于桨尖开孔的旋翼桨尖涡抑制研究,重点分析了开孔位置、数目、直径等参数对桨尖涡结构和旋翼气动性能的影响。旋翼流场数值模拟通过求解旋转坐标系下的Navier-Stokes方程,采用格点格式的有限体积法,结合非结构重叠网格技术。无黏通量计算采用二阶中心格式加人工耗散,湍流模型采用Spalart-Allmaras模型。数值研究表明:桨尖开孔的位置对桨尖涡削弱效果的影响很小;开孔数目越多,孔径越大,桨尖涡的削弱效果越好;开孔旋翼的升力系数较无开孔构型小幅增加,而功率系数则较大幅度增加。
尤延铖 +4 more
core
Effect of Vent Mode on the Differential Pressure Pre-cooling Efficiency of Layered Peaches [PDF]
The objective of this study was to explore the effect of the vent mode of corrugated boxes universally used in the market on the precooling performance of layered peaches and to determine the functional relationship between the precooling environmental ...
CHEN Yingmin, ZHAO Luxi, LINGHU Boxiang, SONG Haiyan
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Numerical simulations for optimizing the liquid water transport in the gas diffusion layer and gas channels of a PEMFC [PDF]
, 2019 The multiple-relation-time (MRT) lattice Boltzmann method with a high-density-ratio two-phase model was used to simulate liquid water transport in the gas diffusion layer (GDL) and gas channels of a high-current-density fuel cell.
Lei, T +4 more
core
Temporal and spatial evolution mechanism of large-diameter borehole pressurerelief and permeable gas seepage in high gas coal seam [PDF]
Mine gas extraction has the dilemma of low extraction rate, short effective extraction cycle, and substandard gas pre-extraction concentration. In order to realize the precise pressure relief and permeability of high gas and low gas permeability coal ...
Cun ZHANG +4 more
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Numerical investigation on the complex flow of propeller/rotor [PDF]
, 2017 螺旋桨/旋翼旋转产生的流场现象非常复杂，尤其是螺旋桨/旋翼与飞机部件之间的气动干扰对飞机的性能有着重要影响。本文基于非结构重叠网格和自适应网格技术，采用改进延迟分离涡模拟（ImprovedDelayedDetachedEddySimulation，IDDES）方法，对两类螺旋桨/旋翼复杂问题进行了数值模拟研究：一是螺旋桨与飞机部件之间的气动干扰，研究了螺旋桨与短舱、螺旋桨与无人机的气动干扰问题；二是直升机旋翼的桨-涡干扰，研究了旋翼桨尖开孔削弱桨尖涡的机理 ...
王旭
core
New prefabricated support structure for TBM tunneling in complex strata of coal mines: engineering practice [PDF]
Tunnel Boring Machines (TBMs) have been successfully applied in the excavation of deep shaft roadways in coal mines, yielding substantial socio-economic benefits.
Bin TANG +4 more
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Transient Investigation of Conceptual Twin Crucible Type Core Catcher Design with Embedded Cooling Tube Using GOTHIC 3D Model [PDF]
In case of a severe accident, the lower head of the reactor pressure vessel will be melted when the corium cannot be effectively cooled after melting. Under the EVR (ex-vessel corium retention) strategy, the molten corium will be released into the core ...
LIU Zhuo1, 2, , YUAN Yidan1, 2, JIA Ningxi1, 2, JIN Yu1, 2
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Gaoya dianqi, 2023 输电线路带电作业机器人的应用是提高输电线路检修效率、降低人工作业事故发生率、建设智能电网的有效途径。机器人工作时处于高强度电磁场环境中，且控制箱内有许多电磁敏感元件，极易被电磁环境影响。目前的电磁防护以定性的经验设计为主，在复杂电磁环境下的定量分析是现阶段的研究重点。为了实现机器人带电作业的安全，文中选择加装引流棒实现机器人等电位作业，对机器人到达作业位置附近时，导线及机器人机械臂附近电场分布随机器人位置的变化规律进行分析，对机器人平台的设计与工作姿态提出了建议。为了实现对机器人控制箱的电磁防护 ...
陈富国 +7 more
doaj
Identifying the lithologies and thicknesses of coal seam roofs and floors based on multiparameter logging of boreholes [PDF]
BackgroundIn the process of coal mining, effective exploration methods for stratigraphic characteristics are crucial to underground operations. The reason is that the accurate stratigraphic characteristics of coal seams, along with the surrounding rocks ...
Baobin GAO +4 more
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