In this paper the effects of the dynamics of vapor-gas bubbles in water on the stability of two-dimensional parallel flows of low void fraction are investigated. Using a small perturbation approach, the equations of motion for the bubbly mixture are linearized and a modified Rayleigh equation governing the inviscid stability problem is obtained. This equation is then used for the stability analysis of hyperbolic tangent shear layers. Thermodynamic equilibrium is assumed in the reference unperturbed state between the vapor in the bubble and the surrounding liquid. The effects of compressibility, inertia and energy dissipation due to the viscosity of the liquid, the transfer of heat and mass between the two phases are included in the bubble dynamic model. In general, the present analysis confirms the stabilizing effect due to the dispersed phase in the liquid. More importantly, it points out some major differences in the stability characteristics of parallel flows containing vapor-gas bubbles when compared to those containing noncondensable gas. In particular, depending on the pressure and temperature of the liquid, the dynamic response of bubbles with a dominant content of vapor can be quite different from that of gas bubbles, thus resulting in stability characteristics that deviate substantially from those of flows containing bubbles of non-condensable gas.
|Titolo:||Linear Stability of Parallel Two-Dimensional Shear Layers Containing Vapor-Gas Bubbles|
|Anno del prodotto:||1997|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|