Lagrangian-based investigation of gaseous jets injected into water by finite-time Lyapunov exponents
Gaseous jets injected into water are found in a variety of engineering applications, and the flow is essentially unsteady and turbulent. Additionally, the high water-to-gas density ratio can result in complicated flow structures; hence, It is important to investigate their flow structures to predict the dynamical behaviors effectively.Lagrangian coherent structures (LCS) defined by the ridges of the finite-time Lyapunov exponent (FTLE) is utilized in this study to elucidate the multiphase interactions in gaseous jets injected into water under the framework of the Navier-Stokes flow computations.The highlighted phenomena of the jet transportation can be observed by the LCS method, including expansion, bulge, necking/breaking, and backattack.Besides, the observation of the LCS reveals that the back-attack stage is caused due to the injected gas has difficulties approaching the downstream region after the necking/breaking. The results indicate that the FTLE field has the potential to identify the structures of multiphase flows, and the LCS can capture the interface/barrier or the vortex/circulation region.
Finite-Time Lyapunov Exponents Lagrangian Coherent Structures Multiphase flow Gaseous jets injected into water
Jia-Ning Tang Ning-Fei Wang
School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China
国际会议
International Conference on Advances in Engineering 2011(2011年工程研究进展国际学术会议 ICAE2011)
南京
英文
828-834
2011-12-17（万方平台首次上网日期，不代表论文的发表时间）