Spouting of vertical submerged axisymmetric jets in relatively narrow channels

The spouting of vertical submerged axisymmetric jets from under the free surface in relatively narrow channels is experimentally and numerically studied. The existence of self-oscillation regimes with transverse displacements of the free-surface elevation is found for wide ranges of constitutive parameters. Dependencies of the self-oscillation period on the velocities of jets and the initial value of the jet submergence are analyzed for various jet diameters. Some spouting regimes are numerically analyzed. A new class of self-oscillation spouting regimes known also as quasiregular is discovered for high-speed small-diameter jets when the depth of their submergence is relatively small. A comparison is made with the results obtained for plane submerged jets.