Effects of Radial-Tangential Discharge Channels on a Rotary Atomizer Performance

The effects of tangential injection on the primary breakup dynamic and spray characteristics of a rotary atomizer are experimentally investigated under atmospheric conditions. To achieve this goal, two types of atomizers with radial and radial-tangential discharge channels are used to compare their results. The breakup process as well as the primary breakup length are compared with the aid of the high-magnification shadow imaging technique. The droplet size distributions are obtained by the use of the particle/droplet image analyses technique at the same plane of measurement to compare the atomization quality in radial and radial-tangential discharge channels. The results reveal that the breakup process of the injected liquid stream is extensively affected by the tangential orientation of discharge channels of the atomizer disk. The atomization process is improved in the radial-tangential case as a result of the enhancement of aerodynamic forces acting on the exposed surface of the liquid stream. The droplet sizing indicates that the Sauter mean diameter values are decreased by the application of radial-tangential injection in all considered operating conditions.