INVESTIGATION ON THE MASS ENTRAINMENT OF AN ACOUSTICALLY CONTROLLED ELLIPTIC JET

The mass entrainment of the elliptic jet under acoustic excitations wi th fundamental and subharmonic frequency were investigated experimenta lly in this paper. Results show that the azimuthal deformation increas es the interfacial area and engulfs more fluid from surrounding into t he free shear layer, it implies the azimuthal deformation plays an imp ortant role in the mass transfer of an elliptic jet. Results also reve al that most of the entrainment occurs around the minor-axis plane, bu t the mass can be entrained significantly around the major-axis plane when the elliptic jet under the subharmonic frequency excitation, i.e. , f(e)(f(0)/2,f(0)/2). It proposes that the subharmonic frequency exci tation is effective to increase the mass entrainment of the elliptic j et. (C) 1998 Elsevier Science Ltd.