单裂隙中开度及粗糙度对Forchheimer公式特征参数的影响
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摘要
Forchheimer公式已广泛应用于高速非达西渗流计算中,但裂隙开度与粗糙度对公式中的特征参数k和β的影响研究尚不够明确。为此,应用Fluent计算软件,用标准J_(JRC)曲线模拟裂隙结构表面粗糙度,研究了裂隙开度b与裂隙粗糙度(J_(JRC))对渗透率k和非达西系数β的影响。结果表明,粗糙裂隙中发生高速渗流时,渗透率与J_(JRC)呈负相关关系,与裂隙开度呈正相关线性关系,裂隙开度是影响渗透率的主要因素;β随着J_(JRC)的增大而增大,随着裂隙开度的增大而减小;非达西系数与渗透率之间存在着负相关关系,这种关系可用幂函数来较好表达。
The Forchheimer formula has been widely used in the high velocity non-Darcy flow calculation,but the study of the influence of fracture opening and roughness on characteristic parameters k andβin the formula is not clear.In this paper,the surface roughness of fracture was simulated by standard J_(JRC)curve.The influence of fracture opening b and joint roughness coefficient(J_(JRC))on permeability k and non-Darcy coefficientβwas studied based on the Fluent calculation software.The results show that k is negatively correlated with J_(JRC)in the occurrence of high speed seepage in rough fractures,and k has a positive correlation with the fracture opening.Fracture opening b is the main factor for affecting k.βincreases with the increase of J_(JRC),and decreases with the increase of fracture opening.There is a negative correlation betweenβand k,which can be expressed by apower function.
The Forchheimer formula has been widely used in the high velocity non-Darcy flow calculation,but the study of the influence of fracture opening and roughness on characteristic parameters k andβin the formula is not clear.In this paper,the surface roughness of fracture was simulated by standard J_(JRC)curve.The influence of fracture opening b and joint roughness coefficient(J_(JRC))on permeability k and non-Darcy coefficientβwas studied based on the Fluent calculation software.The results show that k is negatively correlated with J_(JRC)in the occurrence of high speed seepage in rough fractures,and k has a positive correlation with the fracture opening.Fracture opening b is the main factor for affecting k.βincreases with the increase of J_(JRC),and decreases with the increase of fracture opening.There is a negative correlation betweenβand k,which can be expressed by apower function.
引文
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[5]许凯,雷学文,孟庆山,等.非达西渗流惯性系数研究[J].岩石力学与工程学报,2012,31(1):164-170.
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[7]黄先伍,唐平,缪协兴,等.破碎砂岩渗透特性与孔隙率关系的试验研究[J].岩土力学,2005,26(9):1 385-1 388.
[8]刘明明,胡少华,陈益峰,等.基于高压压水试验的裂隙岩体非线性渗流参数解析模型[J].水利学报,2016,47(6):752-762.
[9]王媛,顾智刚,倪小东,等.光滑裂隙高流速非达西渗流运动规律的试验研究[J].岩石力学与工程学报,2010,29(7):1 404-1 408.
[2]速宝玉,詹美礼,赵坚.仿天然岩体裂隙渗流的实验研究[J].岩土工程学报,1995,17(5):19-24.
[3]Barton N,Choubey V.The Shear Strength of Rock Joints in Theory and Practice[J].Rock Mechanics,1995,17(5):19-24.
[4]李博,蒋宇静.岩石单节理面剪切与渗流特性的试验研究与数值分析[J].岩石力学与工程学报,2008,27(12):2 431-2 439.
[5]许凯,雷学文,孟庆山,等.非达西渗流惯性系数研究[J].岩石力学与工程学报,2012,31(1):164-170.
[6]张文娟,王媛,倪小东.Forchheimer型非达西渗流参数特征分析[J].水电能源科学,2014,32(1):52-54.
[7]黄先伍,唐平,缪协兴,等.破碎砂岩渗透特性与孔隙率关系的试验研究[J].岩土力学,2005,26(9):1 385-1 388.
[8]刘明明,胡少华,陈益峰,等.基于高压压水试验的裂隙岩体非线性渗流参数解析模型[J].水利学报,2016,47(6):752-762.
[9]王媛,顾智刚,倪小东,等.光滑裂隙高流速非达西渗流运动规律的试验研究[J].岩石力学与工程学报,2010,29(7):1 404-1 408.