Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
Viscoplastic flow simulation using a local ghost-cell immersed boundary method
Submission Author:
Daniel Dall Onder dos Santos , MG , Brazil
Co-Authors:
João Rodrigo Andrade, Aristeu Silveira Neto
Presenter: Daniel Dall Onder dos Santos
doi://10.26678/ABCM.ENCIT2016.CIT2016-0665
Abstract
This paper presents the extension of a well-established immersed boundary/ghost-cell approach, the local directional ghost cell, applied to simulate non-Newtonian viscoplastic laminar flows through 2D geometries. This immersed boundary method extends the solution smoothly across the boundary in the same direction as the discretization it will be used for. The ghost cell value is determined locally for each irregular grid cell, making it possible to treat both sharp corners and thin plates accurately. One of the distinguished features of the immersed boundary method here presented is to apply the method to the fluid viscosity, a scalar property varying in space and time depending on the shear rate. The choice to simulate viscoplastic fluids is based on its great importance on many industrial processes, mainly in the food, cosmetic and oil industries. The time stepping is done using a first order Euler method treating the convective term explicitly and an implicit diffusion term which eliminates the viscous stability constraint. The spatial derivatives are approximated by finite volume method on a staggered, Cartesian and stretched grid method. The central differencing scheme is applied to treat all the terms of momentum equation. This methodology is used firstly to simulate a lid-driven cavity flow without using the immersed boundary method to test and validate the numerical procedure. On a second step, the method is applied for non-Newtonian flows around a circular cylinder kept between two parallel walls.
Keywords
Viscoplastic flow, Immersed Boundary Method
