Research on temporal−spatial relationship between ground fracturing wells and underground drilling for substitution drainage of during extraction exhaustion period [PDF]
, 2022 In order to make use of the favorable extraction conditions formed by ground fracturing to carry out the underground borehole replacement extraction in the drainage exhaustion period of ground fracturing wells, and form the advanced treatment of ground ...
Jian HE +5 more
core +1 more source
, 2022 在默认监测设备经过计量检定，排除仪器本身误差的前提下对有组织废气现场监测中流量偏差的各种原因进行分析，包括测试规范性、处理系统的影响、仪器管路的影响。细数由于截面积错误、开孔位置不规范、排放规律、管道压力损失、系统阻力、旁路及漏风、踩到管路、软管脱落、采样枪放置方向错误等各种因素带来的影响。
沈 利清
core +1 more source
Simulation and analysis of forced air precooling performance of apples with different fruit diameters [PDF]
Objective: To analyze the effect of apples of different fruit diameters on differential pressure precooling under the same box. Methods: Based on the spherical analogy model and heat transfer theory, the CFD unsteady SST k-ω turbulence model was used to ...
GU Xudong +4 more
core +1 more source
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
core +1 more source
, 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
core +1 more source
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
core +1 more source
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
core +1 more source