Entrainment of air into liquids by a high speed continuous solid surface

Abstract The paper reports a wide range of experimental data on air entrainment velocities and apparent dynamic contact angles, were a continuous surface enters The main dimensional correlation took the form: for variables in the range: However, due to the limited range of fluid densities used (0.785-1.26 * 10 3 kg.m 3 ), a simpler correlation for air entrainment velocity was found for the case of the entrainment of air by a plunging solid surface where 0.2 -1 was found to be the corresponding r The critical capillary number C a c was found to lie in the range 0.2 a c The investigation also showed that anomalous behaviour could occur with charged surfaces or surfaces with significant roughness. Surfactant type was al