Numerical Calculation of Fracture Seepage in Rough Rock and Analysis of Local Pressure Drop

The seepage performance of a rock mass mainly depends on the rock fractures developed in it. Numerical calculation method is a common method to study the permeability properties of fractures. Seepage in rock fractures is affected by various factors such as fracture aperture, roughness, and filling, among which aperture and roughness are the two most widely influenced factors. The Navier-Stokes (NS) equation can be solved directly for the seepage flow in rock fractures with good accuracy, but there are problems of large computational volume and slow solution speed. In this paper, the fracture aperture space data is substituted into the local cubic law as an aperture function to form a numerical calculation method for seepage in rough rock fractures, namely, the aperture function method (AFM). Comparing with the physical seepage experiments of rock fractures, the calculation results of AFM will produce a small amount of error under the low Reynolds number condition, but it can greatly improve the calculation efficiency. The high efficiency of calculation makes it possible to apply AFM to the calculation of large-scale 3D rough fracture network models. The pressure drop of fluid in the fracture has viscous pressure drop (VPD) and local pressure drop (LPD). VPD can be calculated using the AFM. After analyzing the results of solving the NS equation for fracture seepage, it is concluded that the LPD includes the pressure drop caused by area crowding in the recirculation zone (RZ), kinetic energy loss in the RZ, kinetic energy loss in the vortices, and other reasons.

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Horizontal momentum and kinetic energy loss of airflow near the surface of sandy beds

Sedimentary Geology ◽

10.1016/j.sedgeo.2010.12.007 ◽

2011 ◽

Vol 234 (1-4) ◽

pp. 116-119 ◽

Cited By ~ 1

Author(s):

Ping Lü ◽

Zhibao Dong

Keyword(s):

Kinetic Energy ◽

Energy Loss ◽

Horizontal Momentum ◽

Kinetic Energy Loss

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Tortuosity and the Averaging of Microvelocity Fields in Poroelasticity

Journal of Applied Mechanics ◽

10.1115/1.4007923 ◽

2013 ◽

Vol 80 (2) ◽

Cited By ~ 5

Author(s):

M. F. Souzanchi ◽

L. Cardoso ◽

S. C. Cowin

Keyword(s):

Porous Media ◽

Kinetic Energy ◽

Energy Loss ◽

Cancellous Bone ◽

Quantitative Measure ◽

Pore Fluid ◽

Fluid Viscosity ◽

Anisotropic Porous Media ◽

Pore Architecture ◽

Kinetic Energy Loss

The relationship between the macro- and microvelocity fields in a poroelastic representative volume element (RVE) has not being fully investigated. This relationship is considered to be a function of the tortuosity: a quantitative measure of the effect of the deviation of the pore fluid streamlines from straight (not tortuous) paths in fluid-saturated porous media. There are different expressions for tortuosity based on the deviation from straight pores, harmonic wave excitation, or from a kinetic energy loss analysis. The objective of the work presented is to determine the best expression for tortuosity of a multiply interconnected open pore architecture in an anisotropic porous media. The procedures for averaging the pore microvelocity over the RVE of poroelastic media by Coussy and by Biot were reviewed as part of this study, and the significant connection between these two procedures was established. Success was achieved in identifying the Coussy kinetic energy loss in the pore fluid approach as the most attractive expression for the tortuosity of porous media based on pore fluid viscosity, porosity, and the pore architecture. The fabric tensor, a 3D measure of the architecture of pore structure, was introduced in the expression of the tortuosity tensor for anisotropic porous media. Practical considerations for the measurement of the key parameters in the models of Coussy and Biot are discussed. In this study, we used cancellous bone as an example of interconnected pores and as a motivator for this study, but the results achieved are much more general and have a far broader application than just to cancellous bone.

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Hardware-in-the-Loop estimation of kinetic energy loss in urban driving cycles using bond graph based unified modeling framework

2014 IEEE International Conference on Computational Intelligence and Computing Research ◽

10.1109/iccic.2014.7238428 ◽

2014 ◽

Author(s):

Sampath Kumar Veera Ragavan ◽

Madhavan Shanmugavel ◽

Foo Yew Jin

Keyword(s):

Kinetic Energy ◽

Energy Loss ◽

Bond Graph ◽

Hardware In The Loop ◽

Modeling Framework ◽

Unified Modeling ◽

Driving Cycles ◽

Kinetic Energy Loss

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Kinetic energy loss in sputtering

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/0168-583x(89)90722-2 ◽

1989 ◽

Vol 42 (2) ◽

pp. 290-292 ◽

Cited By ~ 10

Author(s):

M.H. Shapiro

Keyword(s):

Kinetic Energy ◽

Energy Loss ◽

Kinetic Energy Loss

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Numerical modelling of transonic centripetal flow in radial turbine blade cascade

MATEC Web of Conferences ◽

10.1051/matecconf/201816802008 ◽

2018 ◽

Vol 168 ◽

pp. 02008

Author(s):

Petr Straka

Keyword(s):

Experimental Data ◽

Kinetic Energy ◽

Numerical Modelling ◽

Energy Loss ◽

Linear Representation ◽

Buffer Zone ◽

Blade Cascade ◽

Radial Turbine ◽

Paper Method ◽

Kinetic Energy Loss

Numerical modelling of transonic centripetal turbulent flow in radial blade cascade is described in this paper. Method of the confusor buffer zone is applied to overcome some numerical obstacles related with specifical properties of the outlet confusor. Kinetic energy loss coeficient of the radial blade cascade is compared with its linear representation and with experimental data.

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Структура потока в межлопаточном канале соплового аппарата с поворотной диафрагмой

Aerospace technic and technology ◽

10.32620/aktt.2021.4sup2.05 ◽

2021 ◽

pp. 35-43

Author(s):

Александр Григорьевич Жирков ◽

Александр Павлович Усатый ◽

Елена Петровна Авдеева ◽

Юрий Иванович Торба

Keyword(s):

Pressure Drop ◽

Kinetic Energy ◽

Energy Loss ◽

Numerical Study ◽

Working Fluid ◽

Relative Pressure ◽

Pressure Drops ◽

Vortex Zone ◽

Flat Flow ◽

Tube Channel

In the process of developing a numerical study method of a flat flow around a snap line with a rotary diaphragm, calculations were made at various degrees of opening the rotary diaphragm δ and pressure drops on the grille. As a result of calculations, for small degrees, the opening of the rotary diaphragm, complex patterns of the flow were obtained, in the inter-tube channel of the nozzle apparatus. The article presents some results of a numerical study of the supersonic flow in the channel of the nozzle apparatus with the degree of opening the rotary diaphragm δ = (0.15 ÷ 0.3). Modeling and calculating the flow of the working fluid is made using the Fluent software package. The construction of the calculated areas bounded by one inter-tube channel, for varying degrees of opening the diaphragm of the nozzle apparatus. Grids are built for calculated areas. Calculations were carried out for δ = (0.15 ÷ 0.3) and with different degrees of pressure drop on the grille. As a result of the calculations performed, the flow patterns in the inter-tube canal were obtained and behind it, and the distribution of the coefficients of the kinetic energy loss on the lattice front at various degrees of the discovery of the diaphragm at the inlet in the nozzle apparatus. According to the results of the work carried out, the following conclusions can be drawn: the structure of the stream in the inter-tube channel, the nozzle apparatus at small detection of the discovery, is divided into two parts: a supersonic core of the spawth of the blade and a dialing, the vortex zone at the back of the blade; The supersonic thread kernel at certain values of the relative pressure drop on the lattice (or the air flow values through the grid) is separated by shock fronts into several areas; The coefficients of energy loss, for small degrees of discovery, decrease with a decrease in the relative pressure drops (with an increase in the rate of expiration of the flow from the nozzle lattice); The greatest contribution to the magnitude of the loss of kinetic energy is introduced by a vortex zone in the inter-tube channel, and not wave phenomena in the core of the flow; Optimization of the flow part of the nozzle apparatus must be carried out in order to reduce areas with vortex flow. The results obtained in this work will be used to develop a methodology for a numerical study of the spatial flow around the nozzle lattices with rotary diaphragms.

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Motions of the running horse and cheetah revisited: fundamental mechanics of the transverse and rotary gallop

Journal of The Royal Society Interface ◽

10.1098/rsif.2008.0328 ◽

2008 ◽

Vol 6 (35) ◽

pp. 549-559 ◽

Cited By ~ 80

Author(s):

John E.A. Bertram ◽

Anne Gutmann

Keyword(s):

Kinetic Energy ◽

Energy Loss ◽

Water Surface ◽

Fundamental Difference ◽

Centre Of Mass ◽

Transition Strategies ◽

Kinetic Energy Loss

Mammals use two distinct gallops referred to as the transverse (where landing and take-off are contralateral) and rotary (where landing and take-off are ipsilateral). These two gallops are used by a variety of mammals, but the transverse gallop is epitomized by the horse and the rotary gallop by the cheetah. In this paper, we argue that the fundamental difference between these gaits is determined by which set of limbs, fore or hind, initiates the transition of the centre of mass from a downward–forward to upward–forward trajectory that occurs between the main ballistic (non-contact) portions of the stride when the animal makes contact with the ground. The impulse-mediated directional transition is a key feature of locomotion on limbs and is one of the major sources of momentum and kinetic energy loss, and a main reason why active work must be added to maintain speed in locomotion. Our analysis shows that the equine gallop transition is initiated by a hindlimb contact and occurs in a manner in some ways analogous to the skipping of a stone on a water surface. By contrast, the cheetah gallop transition is initiated by a forelimb contact, and the mechanics appear to have much in common with the human bipedal run. Many mammals use both types of gallop, and the transition strategies that we describe form points on a continuum linked even to functionally symmetrical running gaits such as the tölt and amble.

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Cosmic Gas Thermodynamics at z = 1089

10.21203/rs.3.rs-966087/v1 ◽

2021 ◽

Author(s):

Martin Reid Johnson

Keyword(s):

Kinetic Energy ◽

Energy Loss ◽

Ideal Gas ◽

Λcdm Model ◽

Universal Expansion ◽

The Universe ◽

Kinetic Energy Loss

Abstract The Universe at z = 1089 is treated as an expanding ideal gas. Its internal kinetic energy loss exceeds the amount absorbed by gravity and drives further expansion. A Hubble relation (Hg) is derived and compared to the value found by the ΛCDM model (HΛ) over the range z = 1089 to 0. The results suggest that the adiabatic release of energy from cosmic gas accounts for about half of present-day Universal expansion.

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