Numerical Computation On Deformation And Breakup Process Of A Liquid Drop And A Liquid Column Under The Effect Of The High-speed Gas Flow Induced By A Shock Wave

The problem on RM instability is a very complex nonlinear physical problem,as well one of the main content of research on high energy density physics. It has asignificant and extensive research background on the fields of astrophysics, the ICFTech, inertial fusion energy, underwater explosion, the space rocket engine andnational defense. The major research method on the current international instabilityproblem is using the shock wave tube to perform the RM instability experimentalstudy on air to air interface, meanwhile carrying out the corresponding numericalsimulation and theoretical analysis. In this paper, based on a series of shock wave tubeexperiments, a numerical investigation and analysis is carried out for the interactionbetween shock wave and a liquid drop, or a liquid column in the horizontal shockwave tube.The contents of numerical calculation in this paper are mainly done by using theFluent. Based on the experimental parameters, the numerical simulations on theevolution process of liquid drops and columns with different initial diametersinteracted by shock waves with Mach1.1and1.25are carried out. In the experiments,shock wave is generated when the high pressure gas breaks the aluminum diaphragm.In the simulation, before it starts we set high pressure gas in the shock wave tube.When the computation starts, the high pressure gas moves to the right and influencesthe low pressure area, and the shock wave is generated. In this paper, numericalcomputations on the shock wave transmission in the shock wave tube, the interactionbetween shock wave and a liquid drop or a liquid column are done. Based on theparameter contours of the deformation process, a detailed analysis are done to theentire process.By analyzing the change of the parameters and comparing with the experimentalresults, we got conclusions here: In the shock wave tube experiments, there weredifferences between the numerical computation results and the theoretical calculation results of shock wave tube. In the shock wave tube experiments, the discontinuitysurface of density appeared in the gas flow after shock wave. The numericalcomputation on the interaction between a shock wave and a liquid column can besolved through3D simulation. To get a initial disturbance on the surface of the liquidcolumn and make the software to run smoothly are two difficulties. In the calculationof interaction between a shock wave and a liquid drop, as the shock wave passingthrough the liquid drop, parameters like velocity, temperature et.al are not influenced.But the pressure of the droplet is influenced by the time the shock wave hit the droplet.As effecting by the gas flow after the shock wave, the liquid drop deforms and splitsup continuously. The numerical simulation results have shown that during the liquiddrop`s deformation process, the pressure, velocity and viscosity have a similarchanging trend. But the change rates have slightly differences. After compared withthe experimental data and verified by numerical simulation, we think the Webernumber is an unstable factor in the fragmentation process of the liquid drop. Itaccelerates the breakup of the droplet. We think that the Oh number inhibitory effectsthe breakup of the droplet through comparing the numerical simulation result ofGlycerin and Experiment4. Meanwhile, we have observed the phenomenonanalogous to the Karman Vortex Street. We think the big viscosity coefficient ofGlycerin led to this phenomenon.