Start
Jul 23, 2015 - 17:00
End
Jul 23, 2015 - 18:00
Venue
Room 118 Creativity Hall Chemical Engineering
Event Type
Speaker
Dr.Gourav Tomar Professor Department of Mechanical Engg. IISc Bangalore India. >
Title
Smoothed Particle Hydrodynamics
Abstract : Smoothed Particle Hydrodynamics (SPH) is a meshless particle based Lagrangian numerical method that has been in development for the past three decades. Commensurate with the exponential growth in computational power SPH has been increasingly applied to solve problems of greater complexity in fluid mechanics solid mechanics interfacial flows astrophysics and in interdisciplinary problems like fluid-structure interaction granular flows fracture mechanics solidification etc. Incompressible Smoothed Particle Hydrodynamics (ISPH) a variant of SPH solves for a pressure field to achieve incompressibility as opposed to the original SPH method which uses a stiff equation of state to achieve the same. ISPH is known to reduce spurious pressure fluctuations and also computational time. In this talk several new improvements on the existing ISPH algorithm to simulate free surface flows will be presented. We will also discuss the various challenges encountered in implementing the ISPH algorithm in a computer program. We employ the proposed ISPH free surface algorithm to simulate water entry of projectiles. The flow features and energy transfer due to entry of solid bodies of different shapes density and initial spin into water have been studied. By performing a theoretical analysis we demonstrate that although SPH is known to be inherently mass conserving due to finite timestep updates it does not conserve volume. This is equally applicable to other meshfree particle based methods as well. We propose a novel deformation-gradient based algorithm for better volume conservation. Finally we will show that combining the ISPH algorithm proposed in this study with the weakly compressible SPH simulations involving compressible-incompressible two fluid systems can also be performed.