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Abstract
CALCULATED RADIUS OF NONLINEAR ZONE AROUND FISSURED-KARSTIFIED ROCKS TAPPING WELL
Summary
The paper presents an equation in which the value of critical hydraulic gradient (i.e. gradient corresponding to a transition from laminar movement to the turbulent) occurs in complex form. The equation is proposed using the Kerkis equation, for drawdown in well and assuming that there exists turbulent movement zone with a definite radius, the equation for continuity of fluid flow and the Darcy Law as starting points. Using the new equation, critical gradients and radii of zone of turbulent movement are evaluated on the basis of results of test pumpings.
The obtained values of critical hydraulic gradients give further support to the point of view that the zone of turbulence around pumped well is fairly narrow also in fissured-karstified aquifer rocks when drawdowns are moderately large. The analysis of correlation of critical hydraulic gradient and permeability showed that the former decreases in irregular (nonlinear) way along with increase of the latter.
Summary
The paper presents an equation in which the value of critical hydraulic gradient (i.e. gradient corresponding to a transition from laminar movement to the turbulent) occurs in complex form. The equation is proposed using the Kerkis equation, for drawdown in well and assuming that there exists turbulent movement zone with a definite radius, the equation for continuity of fluid flow and the Darcy Law as starting points. Using the new equation, critical gradients and radii of zone of turbulent movement are evaluated on the basis of results of test pumpings.
The obtained values of critical hydraulic gradients give further support to the point of view that the zone of turbulence around pumped well is fairly narrow also in fissured-karstified aquifer rocks when drawdowns are moderately large. The analysis of correlation of critical hydraulic gradient and permeability showed that the former decreases in irregular (nonlinear) way along with increase of the latter.