Boundary Layer Around a Liquid Jet

The phenomenon of air wake caused by a train of liquid drops is studied in this paper by approximating the train to a cylindrical jet emerging from a nozzle. The boundary layer equations are derived by applying continuity of jet mass and matching the loss of jet momentum with the air drag on the jet. These equations are solved numerically and compared with experiments in which the velocity change of the jet along the stream is carefully measured through measurements of drop distances. Good agreement is obtained between experimental results and the analysis.