What does extensional flow mean?
defor- mation
The simplest definition of an extensional flow is that it is a defor- mation that involves stretching along streamlines.
How is extensional viscosity measured?
Extensional viscosity can be measured using rheometers that apply extensional stress. Acoustic rheometer is one example of such devices.
What is shear flow in fluids?
In fluid mechanics, the term shear flow (or shearing flow) refers to a type of fluid flow which is caused by forces, rather than to the forces themselves. In a shearing flow, adjacent layers of fluid move parallel to each other with different speeds.
What is a simple shear flow?
In simple shear flow, the vast majority of polymer solutions are pseudoplastic in nature, which means that the viscosity is decreased as the shear rate is increased. The viscosity related to this type of flow is shear-thickening viscosity. In other words, the fluid has dilatant behavior.
Is a normal fault extensional?
An extensional fault is a fault caused by stretching of the Earth’s crust. In most cases such a fault is also a normal fault, but may create a shallower dip usually associated with a thrust fault. Extensional faults are generally planar.
What is compressional flow?
Compressional flow: where the gradient becomes less steep or the ice encounters a major obstacle the ice mass slows, backs up, crevasses close and there are thrust fractures as the ice mass compresses. The increased thickness of ice exerts greater pressure on bedrock and can result in more extensive pressure erosion.
What is shear viscosity?
1. A coefficient that characterizes the viscous properties of a fluid and is related to the absorption (loss) of energy (or else, damping) due to the presence of velocity gradients in the fluid.
Are normal faults extensional?
Where does the maximum shear flow occur?
neutral axis
The maximum shear stress occurs at the neutral axis and is zero at both the top and bottom surface of the beam. Shear flow has the units of force per unit distance.
What is steady shear flow?
Steady Slit Flow. Sometimes called plane Poiseuille flow, this flow can also be used to measure viscosity. The shear stress and shear rate vary from zero on the plane of symmetry to maximum values at the walls. 3. Annular Pressure Flow.
Is pure shear coaxial?
Pure shear is the deformation in the x axis resulting in no change of area. During pure shear the axes of the strain ellipsoid do not rotate and the incremental and finite strain ellipsoids are coaxial.
Is a reverse fault caused by compression?
Reverse faults occur in areas undergoing compression (squishing). If you imagine undoing the motion of a reverse fault, you will undo the compression and thus lengthen the horizontal distance between two points on either side of the fault.