Behavior of suspended natural rubber balls in water at small Reynolds numbers

Abstract

This study explores the experimentally verifiable rheological parameters of sparsely spaced suspensions of periodically forced rubber spheres in water at low Reynolds numbers. The experimentally verifiable rheological parameters are first normal stress difference, second normal stress difference, intrinsic pressure, and relative viscosity. These parameters are observed to be dependent on the amplitude of the periodic force, particle Reynolds numbers and the volume fraction. The main aim of this study is to determine how well the neutrally buoyant rubber balls (isoprene) flow with the solutions at low Reynolds numbers when forced periodically. The motivation of the problem consideration is to study the collective behavior of the balls when suspended in a dilute limit. An interesting and novel feature of these balls is their non-Newtonian behavior in the Newtonian frame of reference. The model obtained was an integro-differential-equation, which was solved using the Runge–Kutta fourth-order method. Results reveal that the relation between the intrinsic pressure and relative viscosity depicts a nonlinear relation with Reynolds number and proportional to volume fraction. When Rubber balls are forced periodically, they exhibit the non-Newtonian behavior. The relation between the intrinsic pressure and relative viscosity depicts a nonlinear relation with Reynolds number and proportional to volume fraction.