Stripping breakup process of a single liquid droplet under the impact of a planar shock wave is investigated both experimentally and numerically. The droplet breakup experiment is conducted in a horizontal shock tube and the evolution of the droplet is recorded by direct high-speed photography. The experimental images clearly illustrate the droplet interface evolution features from its early to relatively late stage. Compressible Euler equations are solved using an in-house inviscid upwind characteristic space-time conservation element and solution element (CE/SE) method coupled with the HLLC approximate Riemann solver. A reduced five-equation model is employed to demonstrate the air/liquid interface. Numerical results accurately reproduce the water column and axi-symmetric water droplet breakup processes in experiments. The present study confirms the validity of the present numerical method in solving the shock wave induced droplet breakup problem and elaborates the stripping breakup process numerically in a long period. Droplet inner flow pattern is depicted, based on which the drives of protrusions emerged on the droplet surface are clearly seen. The droplet deformation is proved to be determined by not only the outer air flow, but also the inner liquid flow.
|Original language||English (US)|
|Title of host publication||21st AIAA International Space Planes and Hypersonics Technologies Conference|
|Publisher||American Institute of Aeronautics and Astronautics (AIAA)|
|State||Published - Mar 2 2017|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research was supported by the opening project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology), numbered KFJJ15-09M, Natural Science Foundation of China project, numbered 11372265, and the projects of Research Grants Council, Hong Kong, under contract number CRF C5010-14E and GRF 152151/16E.