Buckling of thin fluid jets and threads

The quasione-dimensional equations of the dynamics of thin jets are used as the basis for a theoretical study of flexural loss of stability (buckling) in thin jets and threads of high-viscosity fluids flowing slowly and normally onto a plate. The characteristic equation is obtained within linear analysis. Its solution showed that instability arises only in the presence of a longitudinal compressive force in a jet, and when the distance from the exit of the nozzle creating the jet to the plate exceeds a certain value which is critical for the jet in question. This critical value is calculated. It is shown that the instability is aperiodic in nature if gravity is neglected (horizontal jets).