08-12-2012, 03:18 PM
GOVERNING OF “THREE DIMENSIONAL” EQUATION IN GROUND WATER FLOW
GOVERNING OF “THREE.ppt (Size: 350.5 KB / Downloads: 34)
INTRODUCTION
General equations are differential equations that are derived from the physical principal governing the process
In case of ground water flow, the relevant basic physical principals are Darcy law and mass balance
In ground water studies, the fluxes like Darcy flux, average linear velocity are microscopic quantities which are hydraulic gradient and hydraulic properties of the aquifer
In general ground water in thus established for macroscopic flow in porous media have isotropic, anisotropic and transient or study flow
Hydraulic properties are porosity, permeability and hydraulic conductivity depend upon porous media of soil
HYDRAULIC PROPARTIES
Porosity:
. The ratio of volume of openings in the porous media to the bulk volume of porous media
.It is represented in ‘n’.
Permeability:
. The ability of a porous media to allow another porous media to pass though it
. Permeability depend on ability porous media
Hydraulic conductivity:
.hydraulic conductivity represented as ‘k’ that describes which water can move though pore spaces
.it depend on degree of saturation etc
Hydraulic head: (h)
. Combined measures of the elevation and the water pressure at a point in an aquifer which represents the total energy of the water
DARCY’S LAW
Darcy’s experiment consisted of a sand filled in porous media with inlet and outlet for water
Two manometer measure the hydraulic head at two points with in the porous media(h1,h2)
The sand is fully saturated and a study flow of water is forced though it at a volumetric rate of (Q)
Darcy found that
The minus sign is necessary because head decreases in the direction of flow
If the is flow in the positive direction Q is positive ‘s’ direction
and dh/ds is in the negative direction
Conversely when flow is negative direction Q is negative ‘s’ direction and dh/ds is in the positive direction
Darcy’s law is written for the Darcy’s flux which is the discharge per unit cross sectional area
APPLICATIONS OF GROUN WATER FLOW
Applications of hydrological numerical models include ground water flow for mine dewatering predications ,environmental vulnerability study of aquifer/surface water related to acid mine drainage and also a flow model focused on the heap on lean drainage
Generally three dimensional and should be a three dimensional numerical model and also needs to built the hydrological cycle
Three hydrological numerical models should be used three characterization of ground water flow data