Author : Akshay Subramaniam
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (17 download)
Book Synopsis Simulations of Shock Induced Interfacial Instabilities Including Materials with Strength by : Akshay Subramaniam
Download or read book Simulations of Shock Induced Interfacial Instabilities Including Materials with Strength written by Akshay Subramaniam and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Richtmyer-Meshkov instability arising from the interaction of shock waves with material interfaces occurs in many natural and engineering contexts. It plays an important role in supersonic combustion, supernova explosions and presents a major roadblock in achieving sustained fusion in Inertial Confinement Fusion (ICF). The first part of the thesis focuses on high resolution simulations of the Richmyer-Meshkov instability that seek to deduce the effect of spatial inhomogeneity. Simulations performed with high order compact finite difference schemes are compared to experiments and show good qualitative and quantitative comparison. Analysis of the simulation results is focused on understanding the turbulence energy dynamics and mixing processes. A scale dependent coarse-graining approach is developed and used to decipher the energy dynamics in scale space. The coarse-graining analysis shows the effect of compressibility in inhomogeneous Richtmyer-Meshkov flows. A new mixing measure based on entropy generation by diffusive mass flux is introduced and evidence for a mixing cascade in scale space is presented. Results of energy and mixing scaling obtained from the simulations here are compared with experimental results of other inhomogeneous Richtmyer-Meshkov flows and similarities are drawn. In the second portion of the thesis, a new high order Eulerian method for simulating large deformation phenomena in solids as well as flow in liquids and gases in a unified manner is presented. The method uses an inverse deformation gradient tensor to track deformations and the hyperelastic formalism is used in order to maintain thermodynamic consistency. The accuracy and resolution properties of the method are demonstrated through one and two dimensional test problems. The method is extended to be able to simulate interactions between multiple materials using a diffuse interface approximation. The Richtmyer-Meshkov instability between copper and aluminum is simulated and a grid resolution study shows the superior resolution properties compared to previous methods. Finally, a new algorithm to treat sliding at material interfaces is presented in the context of a diffuse interface Eulerian method.
