ID 243

Hydrodynamic Instability on Liquid Column Deformation at a High Weber Number

 

Abstract:

Liquid drop breakup is important for spray combustion and rain erosion of a high-speed aircraft. In the conventional interpretation of liquid drop breakup, the catastrophic breakup, which is assumed being attributable to Rayleigh-Taylor instability at upwind interface, develop at the high Weber number. However, the catastrophic breakup is fully absent at the high Weber number in the liquid breakup behavior of the recent study. This results are not consistent with the conventional interpretation. Additionally, liquid viscosity has some effects of inhibiting hydrodynamic instability and the drop deformation. Therefore, the liquid viscosity effects on the liquid drop deformation are investigated in this study. Both the deformation due to the Rayleigh-Taylor instability and invitation effect of drop deformation by the liquid viscosity can valid on two-dimensional simulation. Hence, we simulate a shock wave interaction with a liquid column. A ghost fluid method is adopted. A level-set methods are applied as interface capturing method. The ghost fluid is obtained from solutions of Riemann problem at interface. A grid refinement tests were conducted. Although the upwind interfaces are relatively smooth for the coarse meshes, the upwind interfaces corrugate for the fine meshes. From these results, this simulation require fine meshes to obtain the deformations of the upwind interfaces of the liquid columns. The liquid viscosity coefficients are simulated in the range from zero to water degree it, in order to investigate the viscosity effects on liquid drop deformation. The liquid column deformation is dependent on liquid viscosity.