We have performed an experimental study on the evolution of sand ripples formed under the action of an oscillatory flow. An annular sand-water cell was used in order to investigate a wide range of parameters. The sand ripples follow an irreversible condensation mechanism from small to large wavelength until a final state is reached. The wavelength and the shape of these stable sand patterns are...

This paper demonstrates the deterministic errors in thermocouple measurements, or bias, through numerical simulation and illustrates the impact of these erroneous measurements on inverse heat conduction problem solutions. The case of molten metal solidifying through cooling in a sand mold is considered. Artificial data for the sand surface temperature and at two different locations below the sa...

Abstract The occurrence of fingered preferential flow depends on both flow and porous media characteristics. The boundary condition of unsaturated infiltration has been investigated to assess whether it produces unstable wetting in homogeneous coarse sands. Laboratory tracer experiments were conducted in two coarse sand materials; for each sand material two initial conditions of air dry and fie...

due to the complex structure of the pressure-adjusting device used in most sprinklersfor variable irrigation, it is not possible to observe the flow behavior of the water passingthrough the flow field. in this paper, an integral three dimensional (3d) numerical modelbased on the structural characteristics of the fluidic sprinkler was constructed to simulatethe flow field distribution using comp...

Sand production and blockage are common during the drilling and production of horizontal oil and gas wells as a result of formation breakdown. The use of high-pressure rotating jets and annular helical flow is an effective way to enhance horizontal wellbore cleanout. In this paper, we propose the idea of using supercritical CO2 (SC-CO2) as washing fluid in water-sensitive formation. SC-CO2 is m...

In the evolution processes of wind blown sand movement and aeolian geomorphology, it always contains some complex behaviors, for example, the nonlinear character of turbulence and attractors, the stochastic character of wind gust, liftoff and movement of sand, the interaction among wind field, sand movement, electric field in wind blown sand flux and thermal diffusion, multi-scale character fro...

in our present research, we focus on the modeling of airflow related to natural disasters, such assand accumulation, with urban form studies. the objective is to find which urban form can promote sand passing andreduce as much as possible stagnation of sand in the building area (streets, alleys, etc.). the urban form design will bediscussed through the simulation of airflow by using computation...

Horqin Sandy Land is located in northeast China (4241’-4515’N, 11835’-12330’E). The wind-sand topography in Horqin Sandy Land can be described as two series--sand deposition and wind erosion. Wind is the natural force for the formation of wind-sandy environment, under windsandy environment, the wind erosion processes such as sand drifting, dust-storm, etc. occurred frequently because of the fre...

abstract land surface hydrological models has importance in the determination of soil moisture and temperature, the rate of evapotranspiration, stream flow by emphasis on the land surface physical and dynamic process descriptions. in this research, vic land surface hydrological model has been used for the land surface temperature and stream flow determination. the vic runoff simulation in each ...

In this research, the variation of ultimate bearing capacity, failure mechanism and deformation pattern of soil beneath two closely square footings have been studied using numerical methods. It is assumed that the adjacent footings are constructed on the surface of sand. The presented numerical analyses are based on explicit-finite-difference code, FLAC3D. The elasto-plastic behavior of soil is...