EFFECT OF SPECIFIC GRAVITY OF SEDIMENT ON RIPPLE FORMATION

Abstract

The plane granular bed when subjected to shear under fluid flow, usually starts deforming in statis-tically regular bed formation called 'ripples'. However, there are certain flow conditions under which the plane bed remains stable. The mechanism of formation of ripples over plane granular beds subjected to shear stress caused by fluid flow has been experimentally studied in this work, with special reference to the effect of specific gravity of the bed material and viscosity of the fluid. The fluids used were Kerosene oil and a mixture of kern-- sane oil and mobil bil. The bed materials used were Sarson and Rai. An improved form of the functional relat- e' d ionship has been obtained using F and .~-".~-~-'._... as the two dimensionless parameters. This plot demarcates the plane and rippled bed quite well. Further it has been shown that in addition to the viscosity of the liquid the density of the grains also influences rippling of the, bed.