scholarly journals A Coupled Thermal-Hydraulic-Mechanical Nonlinear Model for Fault Water Inrush

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 120 ◽  
Author(s):  
Weitao Liu ◽  
Jiyuan Zhao ◽  
Ruiai Nie ◽  
Yuben Liu ◽  
Yanhui Du
Keyword(s):  
Numerical Simulation ◽  
Fault Zone ◽  
Water Flow ◽  
Water Inrush ◽  
Great Influence ◽  
Simulation Method ◽  
Coupling Model ◽  
Flow Equation ◽  
Nonlinear Flow ◽  
Flow Process

A coupled thermal-nonlinear hydraulic-mechanical (THM) model for fault water inrush was carried out in this paper to study the water-rock-temperature interactions and predict the fault water inrush. First, the governing equations of the coupled THM model were established by coupling the particle transport equation, nonlinear flow equation, mechanical equation, and the heat transfer equation. Second, by setting different boundary conditions, the mechanical model, nonlinear hydraulic-mechanical (HM) coupling model, and the thermal-nonlinear hydraulic-mechanical (THM) coupling model were established, respectively. Finally, a numerical simulation of these models was established by using COMSOL Multiphysics. Results indicate that the nonlinear water flow equation could describe the nonlinear water flow process in the fractured zone of the fault. The mining stress and the water velocity had a great influence on the temperature of the fault zone. The temperature change of the fault zone can reflect the change of the seepage field in the fault and confined aquifer. This coupled THM model can provide a numerical simulation method to describe the coupled process of complex geological systems, which can be used to predict the fault water inrush induced by coal mining activities.

Numerical simulation of water inrush in fault zone considering seepage paths

2020 ◽  
Vol 104 (2) ◽  
pp. 1763-1779
Author(s):  
Haitao Yu ◽  
Shuyun Zhu ◽  
Huadong Xie ◽  
Junhua Hou
Keyword(s):  
Numerical Simulation ◽  
Fault Zone ◽  
Water Inrush

scholarly journals Assessment of the Nonlinear Flow Characteristic of Water Inrush Based on the Brinkman and Forchheimer Seepage Model

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 855 ◽  
Author(s):  
Yi Xue ◽  
Yang Liu ◽  
Faning Dang ◽  
Jia Liu ◽  
Zongyuan Ma ◽  
...  
Keyword(s):  
Flow Field ◽  
Water Flow ◽  
Construction Projects ◽  
Underground Mining ◽  
Fractured Rock ◽  
Flow Behavior ◽  
Water Inrush ◽  
Nonlinear Flow ◽  
Fault Permeability ◽  
Forchheimer Flow

Underground fault water inrush is a hydrogeological disaster that frequently occurs in underground mining and tunnel construction projects. Groundwater may pour from an aquifer when disasters occur, and aquifers are typically associated with fractured rock formations. Water inrush accidents are likely to occur when fractured rock masses are encountered during excavation. In this study, Comsol Multiphysics, cross-platform multiphysics field coupling software, was used to simulate the evolution characteristics of water flow in different flow fields of faults and aquifers when water inrush from underground faults occurs. First, the Darcy and Brinkman flow field nonlinear seepage models were used to model the seepage law of water flow in aquifers and faults. Second, the Forchheimer flow field was used to modify the seepage of fluid in fault-broken rocks in the Brinkman flow field. In general, this phenomenon does not meet the applicable conditions of Darcy’s formula. Therefore, the Darcy and Forchheimer flow models were coupled in this study. Simulation results show that flow behavior in an aquifer varies depending on fault permeability. An aquifer near a fault is likely to be affected by non-Darcy flow. That is, the non-Darcy effect zone will either increase or decrease as fault permeability increases or decreases. The fault rupture zone that connects the aquifer and upper roadway of the fault leads to fault water inrush due to the considerably improved permeability of the fractured rock mass.

scholarly journals Grout diffusion model in porous media considering the variation in viscosity with time

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881989 ◽  
Author(s):  
Fujin Hou ◽  
Keguo Sun ◽  
Qingdong Wu ◽  
Weiping Xu ◽  
Sijia Ren
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Diffusion Model ◽  
Design Process ◽  
Simulation Method ◽  
Flow Equation ◽  
Diffusion Mode ◽  
Research Results ◽  
Perforated Pipe ◽  
Over Time

Grouting engineering is widely used in water plugging for geotechnical engineering. However, grout is usually treated as a Newton fluid and the viscosity is considered unchangeable over time during the grouting design process. This study proposes a grout diffusion model for porous media that considers the variation in viscosity with time. The flow equation is derived for a single smooth tubule. Then, the microequation of Bingham grout flowing in porous media is obtained. Finally, an assembled diffusion model of spheres and cylinders for grouting using a perforated pipe is proposed. A numerical simulation method is used to verify the grout diffusion mode. The research results can guide grouting design and practical grouting engineering in water plugging and reinforcement.

Fluid-Solid Coupling Numerical Simulation Analysis of Impermeable Rock Mining Seam Floor Failure

2014 ◽  
Vol 1010-1012 ◽  
pp. 1527-1530
Author(s):  
Chun Jie Song ◽  
Cheng Fan
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Water Inrush ◽  
Three Dimensional ◽  
Deep Understanding ◽  
Simulation Method ◽  
Relevant Information ◽  
Simulation Software ◽  
Pressurized Water ◽  
Floor Failure

Based on a deep understanding of FLAC 3D numerical simulation software and the solid-liquid coupling theory and calculation method, this paper established a mining three-dimensional mechanical model under the pressurized water .Using the numerical simulation method, this paper systematically analysis deformation Laws of stress distribution of mining floor, bottom stress, its plastic zone and floor failure depth. By analyzing water inrush flow-solid coupling seepage problem under the conditions of coal mining, and compares with relevant information, verify the rationality of the existing theories and engineering measures, provide a theoretical basis for seeking security and economic exploitation of technical measures.

scholarly journals Evaluation of the Non-Darcy Effect of Water Inrush from Karst Collapse Columns by Means of a Nonlinear Flow Model

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1234 ◽  
Author(s):  
Yi Xue ◽  
Teng Teng ◽  
Lin Zhu ◽  
Mingming He ◽  
Jie Ren ◽  
...  
Keyword(s):  
Construction Projects ◽  
Numerical Solutions ◽  
Water Inrush ◽  
Nonlinear Flow ◽  
Karst Collapse ◽  
Viscous Resistance ◽  
Mining Operations ◽  
Flow Process ◽  
Mining Work ◽  
Forchheimer Flow

Karst collapse columns (KCCs) are naturally formed geological structures that are widely observed in North China. Given their influence on normal mining operations and the progress of mining work, collapse columns pose a hidden danger in coal mining under the influence of manual mining. By communicating often with the aquifer, the water inrush from KCCs poses a serious threat to construction projects. This paper adopts three flow field models, namely, Darcy aquifer laminar flow, Forchheimer flow, and Navier–Stokes turbulent flow, based on the changes in the water inrush flow pattern in the aquifer and laneway, and uses COMSOL Multiphysics software to produce the numerical solutions of these models. As the water inrush flow velocity increases, the Forchheimer flow shows the effect of additional force (inertial resistance) on flow in KCCs, in addition to the effect of viscous resistance. After the joint action of viscous resistance and inertial resistance, the inertial resistance ultimately dominates and gradually changes the water inrush from the KCCs to fluid seepage. Forchheimer flow can comprehensively reflect the nonlinear flow process in the broken rock mass of KCCs, demonstrate the dynamic process from the Darcy aquifer to the final tunnel turbulence layer, and quantitatively show the changes in the flow patterns of the water inrush from KCCs.

scholarly journals The Unsaturated Hydromechanical Coupling Model of Rock Slope Considering Rainfall Infiltration Using DDA

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Xianshan Liu ◽  
Ming Xu
Keyword(s):  
Water Flow ◽  
Rock Slope ◽  
Rainfall Intensity ◽  
Water Pressure ◽  
Great Influence ◽  
Coupling Model ◽  
Rainfall Infiltration ◽  
Discontinuous Deformation Analysis ◽  
Reservoir Rock ◽  
Hydromechanical Coupling

Water flow and hydromechanical coupling process in fractured rocks is more different from that in general porous media because of heterogeneous spatial fractures and possible fracture-dominated flow; a saturated-unsaturated hydromechanical coupling model using a discontinuous deformation analysis (DDA) similar to FEM and DEM was employed to analyze water movement in saturated-unsaturated deformed rocks, in which the Van-Genuchten model differently treated the rock and fractures permeable properties to describe the constitutive relationships. The calibrating results for the dam foundation indicated the validation and feasibility of the proposed model and are also in good agreement with the calculations based on DEM still demonstrating its superiority. And then, the rainfall infiltration in a reservoir rock slope was detailedly investigated to describe the water pressure on the fault surface and inside the rocks, displacement, and stress distribution under hydromechanical coupling conditions and uncoupling conditions. It was observed that greater rainfall intensity and longer rainfall time resulted in lower stability of the rock slope, and larger difference was very obvious between the hydromechanical coupling condition and uncoupling condition, demonstrating that rainfall intensity, rainfall time, and hydromechanical coupling effect had great influence on the saturated-unsaturated water flow behavior and mechanical response of the fractured rock slopes.

Vibration Analysis of High-Speed Vehicles under the Condition of Track Random Irregularity

2011 ◽  
Vol 211-212 ◽  
pp. 525-529 ◽  
Author(s):  
Hong Mei Shi ◽  
Jia Liang Zhou
Keyword(s):  
Differential Equation ◽  
Numerical Simulation ◽  
Vibration Analysis ◽  
High Speed ◽  
Simulation Method ◽  
Coupling Model ◽  
Vertical Coupling ◽  
Vehicle Components ◽  
Track Irregularity ◽  
Random Irregularity

Track irregularity is the most important excitation source of wheel-rail system. The vibration characteristics of vehicle components and track components are analyzed in this paper under the condition of track irregularity by establishing the vehicle - track vertical coupling model. And the establishment of vibration differential equation and numerical simulation method for solving vibration response are described in detail. Finally, the results are given by MATLAB. The method is of great significance for evaluating the dynamic track irregularity and vehicle’s vibration at different running speeds.

scholarly journals Numerical Simulation Analysis of Flow and Heat Transfer in Medium Temperature Boiler

2021 ◽  
Vol 2101 (1) ◽  
pp. 012003
Author(s):  
Na Sun ◽  
Hexu Yang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Waste Heat ◽  
Structural Parameters ◽  
Great Influence ◽  
Industrial Process ◽  
Metallurgical Industry ◽  
Simulation Method ◽  
Waste Heat Boiler ◽  
Medium Temperature

Abstract Waste heat recovery by waste heat boiler is one of the important means to utilize secondary energy, which is widely used in metallurgical industry. However, due to the great influence of production technology and other factors in industrial process, it brings many difficulties to waste heat utilization. Based on the structural parameters and operating parameters of the waste heat boiler, combined with the basic principles of fluid mechanics, the numerical calculation model of the waste heat boiler is established. The flow field and temperature field inside the waste heat boiler are studied and analyzed by numerical simulation method, which provides the necessary basis for its structural optimization.

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