Theoretical investigation of the instability of turbulent capillary jets
MetadataShow full item record
While a stability theory has existed for a long time for the laminar capillary jet, there is a lack of theoretical approaches for the turbulent so far. Experimental results point out, however, that the decomposition mechanisms are similar for the laminar and turbulent case. Therefore, an attempt is made to transfer the approaches of the known stability theory, which in its base features goes back to Rayleigh, to the turbulent case. In order to study the effects of turbulence on the rotationally symmetric surface waves relevant in the laminar case, a model is set up that takes into account the coupling between the turbulent apparent stresses and the elongation of the liquid as a result of jet cross-section changes. This coupling is modeled using Batchelor and Proudman's "Rapid Distortion Theory"; however, the derived results are independent in their qualitative statement of this particular turbulence model. The result of this consideration is that homogeneous turbulence exerts a stabilizing influence on rotationally symmetric surface waves and may even lead to a prevention of this breakup mechanism.