In order to reduce material cost and improve cycle time, consumer products companies must deal with many free surface fluid problem including, sloshing, splashing, and air entrainment. In the example below, engineers from P & G successfully modeled air entrainment during bottle filling.
Predicting Entrained Air using FLOW-3D
Air entrainment (left) and
separation of air and liquid (right)
Entrained air can bulk up the volume of liquid as a container is being filled on a production line. The image on the left below shows 1.2 seconds of filling a bottle that is approximately 20 cm in height. The color shading indicates the volume fraction of air in the liquid. Because of the short time and high degree of mixing in the bottle the air has not had time to rise to the surface and escape. However, as the image on the right shows, after an additional period of about 1.7 seconds, the reduction in liquid volume resulting from air rising to the surface is clearly visible. FLOW-3D's drift flux model allows the separation of components such as air bubbles in liquid to separate out.