Numerical simulation of seepage pressure field of coal seam water-injection in high and low pressure with one-way and bi-directional drilling holes

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.

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Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.2980 ◽

2013 ◽

Vol 295-298 ◽

pp. 2980-2984

Author(s):

Xiang Qian Wang ◽

Da Fa Yin ◽

Zhao Ning Gao ◽

Qi Feng Zhao

Keyword(s):

Numerical Simulation ◽

Stress Distribution ◽

Coal Seam ◽

Coal Mine ◽

Abutment Pressure ◽

Surrounding Rock ◽

Geological Conditions ◽

Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

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New method of monitoring the transmission range of coal seam water injection and correcting the monitoring results

Measurement ◽

10.1016/j.measurement.2021.109334 ◽

2021 ◽

Vol 177 ◽

pp. 109334

Author(s):

Jian Chen ◽

Weimin Cheng ◽

Gang Wang ◽

Haomiao Li ◽

Yanyan Li

Keyword(s):

Coal Seam ◽

Water Injection ◽

New Method ◽

Transmission Range

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Compressible Direct Numerical Simulation of Low-Pressure Turbines: Part I — Methodology

Volume 2D: Turbomachinery ◽

10.1115/gt2014-25685 ◽

2014 ◽

Cited By ~ 2

Author(s):

Richard D. Sandberg ◽

Richard Pichler ◽

Liwei Chen ◽

Roderick Johnstone ◽

Vittorio Michelassi

Keyword(s):

Numerical Simulation ◽

Boundary Layer ◽

Direct Numerical Simulation ◽

Environmental Parameters ◽

Boundary Layer Separation ◽

Low Pressure ◽

Boundary Layer Transition ◽

Layer Transition ◽

Laminar Separation ◽

Background Turbulence

Modern low pressure turbines (LPT) feature high pressure ratios and moderate Mach and Reynolds numbers, increasing the possibility of laminar boundary-layer separation on the blades. Upstream disturbances including background turbulence and incoming wakes have a profound effect on the behavior of separation bubbles and the type/location of laminar-turbulent transition and therefore need to be considered in LPT design. URANS are often found inadequate to resolve the complex wake dynamics and impact of these environmental parameters on the boundary layers and may not drive the design to the best aerodynamic efficiency. LES can partly improve the accuracy, but has difficulties in predicting boundary layer transition and capturing the delay of laminar separation with varying inlet turbulence levels. Direct Numerical Simulation (DNS) is able to overcome these limitations but has to date been considered too computationally expensive. Here a novel compressible DNS code is presented and validated, promising to make DNS practical for LPT studies. Also, the sensitivity of wake loss coefficient with respect to freestream turbulence levels below 1% is discussed.

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