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

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: {A figure is presented} for variables in the range: {A figure is presented} However, due to the limited range of fluid densities used (0.785-1.26 * 10³kg.m³), a simpler correlation for air entrainment velocity was found {A figure is presented} for the case of the entrainment of air by a plunging solid surface where 0.2 <(?s/?9u)>< 3.2m.sec^-1 was found to be the corresponding r. The critical capillary number Ca_c was found to lie in the range 0.2 <Ca_c< 1.26 which agrees very well with a recent study due to Gu. The investigation also showed that anomalous behaviour could occur with charged surfaces or surfaces with significant roughness. Surfactant type was al. © 1984.