Modeling of dynamic bubble deformation and breakup in T-junction channel flow

Bubble deformation and breakup due to strain-rate-induced stress is investigated for a laminar flow configuration. The bubble shape is assumed to be a prolate ellipsoid. A new model for bubble deformation under dynamic load is introduced in the form of an ordinary differential equation for the deformation energy. Breakup is identified with a critical value of the deformation. As an application case, the flow in a joining T-junction is considered with the ratio of the volume flow rate being unity and the outflow Reynolds number being 1800. Dilute, dispersed bubbles with a diameter of 0.5 mm are injected. High-speed shadowgraphy is used and bubble parameters are evaluated via image processing. The capillary number is obtained from a single-phase flow simulation providing the instantaneous shear rate at the position of the bubble. The deformation resulting from the proposed model is then compared with the measured deformation for an exemplary bubble trajectory. •Bubble shape is parametrized by the deformation energy.•A new model approach for deformation under dynamic load scenarios is introduced.•Bubble size and shape are measured via image processing routines.•Stress applied by the continuous phase is obtained using single-phase CFD data.•Predicted and measured deformations are compared for an exemplary trajectory.