Numerical investigation of a single bubble in a rotating Newtonian and shear thinning surrounding

We have studied the dynamics of a single bubble in a shear-thinning and Newtonian fluid undergoing solid body rotation and compared the dynamics with their non-rotating counterpart. We have performed three dimensional numerical simulations with adaptive mesh refinement for both the non-rotating and rotating surrounding. In non-rotating shear-thinning surrounding, the time series evolution of the drag forces experineced by the bubble indicates a negative drag regime, where the net hydrodynamic force assists upward motion of the bubble which is absent in case of the non-rotating Newtonian surroundings. Although the bubble trajectories in case of the non-rotating Newtonian and shear thinning surrounding is similar however the rise velocity in case of the shear thinning surrounding is higher in comparison to the non-rotating Newtonian surrounding. In case of the rotating Newtonian and shear thinning surrounding, Centrifugal and coriolis forces compete with the force of buoyancy to reverse the bubble's ascent. While in case of the rotating Newtonian surrounding the bubble exhibit earlier deflection, shear-thinning surrounding show enhanced trajectory stability due to rheology-induced damping. Finally, our work develops a novel predictive model considering centrifugal, Coriolis and buoyancy forces that accurately estimates the critical time of reversal across a range of Rossby numbers.