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Dispersivity Calculator

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The dispersivity equations are based on a characteristic length, L.  This length is calculated based on the nominal plume radius.  To evaluate the radius, enter the injection rate, duration of injection, formation porosity and formation thickness.  From these data, a piston displacement cylinder is calculated.  Using the radius of that cylinder and a dispersivity of 150 ft, the characteristic length is calculated assuming the edge of the plume is defined by the 1 x 10-9 normalized isoconcentration line. 

Input Variables
Injection rate (in gpm):
Duration (in yrs):
Formation thickness (in ft):
Formation porosity (-):
     
Calculations
Cumulative injection (in million of gallons):
Displacement radius (in ft):
Plume radius [c=1.0e-12] (in ft):
Dispersivity (in ft)
   Xu and Eckstein, 1995 [Enq 12b]:
   Xu and Eckstein, 1995 [Enq 14b]:
   Neuman, 1990 [Eqn 32]:
   Ayra, 1986:

Click to see Equations being evaluated.