Empirical and numerical studies on gas entrainment by impinging jets

The development of the plume of entrained bubbles below an impinging jet has been investigated by means of experimentation and performing CFD calculations. The penetration depth of the plume decreases with increasing quantities of entrained gas in both experiments and simulations. This is due to the fact, that the momentum of the liquid jet below the water level is reduced by friction with the rising bubbles. For a better comparison of the experiments and CFD calculations, non-intrusive measurements of gas void fractions and velocity fields below the jet are needed such as high-speed computer tomography. (orig.)