Evolving solitons in bubbly flows

Evolving Solitons in Bubbly Flows

At the end of the sixties, it was shown that pressure waves in a bubbly liquid obey the KdV equation, the nonlinear term coming from convective acceleration and the dispersive term from volume oscillations of the bubbles. For a variable u, proportional to -p , where p denotes pressure, the appropriate KdV equation can be casted in the form ut 6uu~ + u ~ = 0. The theory of this equation predicts...

Shock Propagation in Polydisperse Bubbly Flows

The effect of distributed bubble nuclei sizes on shock propagation in dilute bubbly liquids is computed using a continuum two-phase model. An ensemble-averaging technique is employed to derive the statistically averaged equations and a finitevolume method is used to solve the model equations. The bubble dynamics are incorporated using a Rayleigh-Plesset-type equation which includes the effects ...

Numerical Simulation of Turbulent Bubbly Flows

A mathematical model for turbulent gas-liquid flows with mass transfer and chemical reactions is presented and a robust solution strategy based on nested iterations is proposed for the numerical treatment of the intricately coupled PDEs. In particular, the incompressible Navier-Stokes equations are solved by a discrete projection scheme from the family of Pressure Schur Complement methods. Nove...

Mathematical Modeling of Bubbly Flows 1

Application of LDA to bubbly flows

The fluctuating velocity field in an air–water bubble column (i.d. 15.2 cm) at a gas fraction of 25% is investigated using backscatter LDA. Since the interpretation of LDA signals in bubbly flows is not straight forward also experiments on a single bubble train are reported. It is discussed that in the latter case when using seeding the backscatter LDA measures predominantly the liquid velocity...