Numerical simulation of viscoelastic fluid flows transition

• Grant number: 17/11068-6
• Support type: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2017
• Effective date (End): August 31, 2018
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal researcher: Analice Costacurta Brandi
• Grantee: Laison Junio da Silva Furlan
• Home Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Several flows of practical interest are of viscoelastic fluids and it is often desirable to know if these flows are in a laminar or turbulent state. Although the hydrodynamics of viscoelastic fluids are strongly affected by the balance between inertia and elastic forces in the flow, the effect of elasticity on the stability of inertial flows has not been completely established. In this project, the laminar-turbulent transition is studied, in which the convection of Tollmien-Schlichting waves will be investigated for the incompressible two-dimensional Poiseuille flow to a viscoelastic fluid, using the constitutive equation Giesekus. For this, Direct Numerical Simulation (DNS) and Linear Stability Theory (LST) will be used to verify the stability of the non-stationary disturbances viscoelastic fluid flows. In the DNS formulation the Navier-Stokes equations coupled with the Giesekus constitutive equation will be solved using high order compact finite difference methods. While in the LST analysis the Orr-Sommerfeld equation is modified to a viscoelastic fluid and solved by the Shooting method. In order to evaluate the maximum amplification rates and the neutral stability curves, different numerical simulations will be performed by varying the dimensionless parameters for the viscoelastic fluid flow and comparing with the Newtonian fluid flow. (AU)