Добірка наукової літератури з теми "Sediment structure. Groundwater-stream water interaction"

Fluids are involved in virtually all geological processes. Obvious examples are phenomena occurring at Earth’s surface in which fluid flow is a highlight: the flow of a lava stream, the play of a geyser, river flow and wind currents, the swash and backswash on a beach. Also obvious are phenomena that occur in the presence of fluid flows, such as sediment motion. Less obvious, but readily imaginable in terms of their behaviors, are fluid motions occurring within Earth’s crust: flows of magma and ground water, and expulsion of brines from sediments during compaction. In addition, a bit of reflection will recall a host of phenomena in which fluid behavior, although not the highlight, may nonetheless take on a significant role: initiation of landslides, seismic activity, glacier movement, taphonomic organization, and fracture mechanics. With these should be considered instances in which the geological material containing a fluid can influence its fundamental behavior at a molecular scale. An example is flow through very small rock pores, where molecular forces interacting among fluid molecules and pore surfaces can lead to a structural arrangement of the fluid molecules such that their mechanical behavior is unlike that which occurs in large pores, where the bulk of the fluid is “far” from pore surfaces. It is thus understandable that to describe many geologic phenomena requires knowing how fluids work. It is also natural to begin by considering how fluids behave in a general way, then in turn, how they are involved in specific geological processes. There are several approaches for describing fluids and their motions, and the choice of one, or some combination, depends on the sort of insight desired as well as the specific problem being considered. Fluid statics, as the name implies, involves considering the properties of fluids that are at rest in some inertial frame of reference. Note that this frame of reference may actually be moving relative to the Earth frame of reference, so long as the fluid motion is like that of a rigid body. An important example of our use of fluid statics will be in developing the hydrostatic equation, which formalizes how fluid pressure varies with depth.

Marine Hydrokinetic Turbines (MHkT) are a new class of renewable energy devices that harvest the kinetic energy of the flowing water in rivers or tides. In these environments, the approach flow contains elevated levels of free-stream turbulence (FST) and large coherent structures, which affect the performance and structural loading of the turbine as well as the signature of the downstream wake. Very little is understood about these interactions and how they cross-couple to impact river morphology, flood conveyance, and sediment transport. The current work uses controlled laboratory experiments