The validity of the cubic law for laminar flow of fluids through open fractures consisting of parallel planar plates has been established by others over a wide range of conditions with apertures ranging down to a minimum of 0.2 µm. The law may be given in simplified form by Q/Δh = C(2b)3, where Q is the flow rate, Δh is the difference in hydraulic head, C is a constant that depends on the flow geometry and fluid properties, and 2b is the fracture aperture. The validity of this law for flow in a closed fracture where the surfaces are in contact and the aperture is being decreased under stress has been investigated at room temperature by using homogeneous samples of granite, basalt, and marble. Tension fractures were artificially induced, and the laboratory setup used radial as well as straight flow geometries. Apertures ranged from 250 down to 4µm, which was the minimum size that could be attained under a normal stress of 20 MPa. The cubic law was found to be valid whether the fracture surfaces were held open or were being closed under stress, and the results are not dependent on rock type. Permeability was uniquely defined by fracture aperture and was independent of the stress history used in these investigations. The effects of deviations from the ideal parallel plate concept only cause an apparent reduction in flow and may be incorporated into the cubic law by replacing C by C/ƒ. The factor ƒ varied from 1.04 to 1.65 in these investigations. The model of a fracture that is being closed under normal stress is visualized as being controlled by the strength of the asperities that are in contact. These contact areas are able to withstand significant stresses while maintaining space for fluids to continue to flow as the fracture aperture decreases. The controlling factor is the magnitude of the aperture, and since flow depends on (2b)3, a slight change in aperture evidently can easily dominate any other change in the geometry of the flow field. Thus one does not see any noticeable shift in the correlations of our experimental results in passing from a condition where the fracture surfaces were held open to one where the surfaces were being closed under stress.

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VALIDITY OF CUBIC LAW FOR FLUID FLOW IN A DEFORMABLE ROCK FRACTURE - eScholarship

Background
Engineering student team projects are frequently used to meet professional learning outcomes. Industrial and organizational psychologists study teams in the industry settings for which we prepare students, yet this research does not effectively inform engineering education.

Purpose
This research review sought to demonstrate the relevance of literature on teams literature from industrial and organizational psychology to engineering education and to identify implications for practice and future directions for research.

Scope/Method
Phase 1 systematically reviewed 104 articles published from 2007 to 2012 describing engineering and computer science student team projects and sought to answer the following questions: What professional learning outcomes have been met by team projects? What negative student team behaviors have faculty sought to minimize? What literature has been used to inform development of teamwork outcomes? Phase 2 reviewed five team effectiveness constructs selected according to the results of Phase 1: social loafing, interdependence, conflict, trust, and shared mental models. Examples from Phase 1 articles and our own work explain how this research informs facilitation and assessment of engineering student teams.

Conclusions
Engineering faculty sought to achieve a variety of outcomes through team projects, including teamwork, communication, sustainability, and consideration of global/societal design context. They sought to avoid social loafing and conflict while building trust to ensure equal team effort. That few Phase 1 articles engaged the literature about team effectiveness indicates there is great opportunity to apply industrial and organizational psychology research to engineering education.

Team Effectiveness Theory from Industrial and Organizational Psychology Applied to Engineering Student Project Teams: A Research Review

Thermo-hydro-mechanical-chemical couplings controlling CH4 production and CO2 sequestration in enhanced coalbed methane recovery

Porosity and permeability characterization of coal: A micro-computed tomography study

A critical review of low salinity water flooding: Mechanism, laboratory and field application

Injecting pure N2 and CO2 to coal for enhanced coalbed methane: Experimental observations and numerical simulation

An experimental study of improved oil recovery through fines-assisted waterflooding

Permeability variation associated with fines production from anthracite coal during water injection

bility due to large permeability contrasts. The most accurate upscaling
technique is employing Darcy’s law. A key part of the study is the establishment of porosity transforms between highresolution
and low-resolution images to arrive at a calibrated porosity map to constraint permeability estimates for the whole
core.

Furqan Hussain

Papers

Injecting pure N2 and CO2 to coal for enhanced coalbed methane: Experimental observations and numerical simulation

An experimental study of improved oil recovery through fines-assisted waterflooding

Permeability variation associated with fines production from anthracite coal during water injection

Permeability Upscaling for Carbonates from the Pore-Scale Using Multi-Scale Xray-CT Images

Fines migration during supercritical CO2 injection in sandstone