Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Stability Analysis of Oldroyd-B and Giesekus Fluids in a Planar Jet Flow
Submission Author:
Rafael de Lima Sterza , São Paulo
Co-Authors:
Rafael de Lima Sterza, Leandro Franco de Souza, André Cavalieri, Marcio Teixeira de Mendonca, Analice Costacurta Brandi
Presenter: Rafael de Lima Sterza
doi://10.26678/ABCM.COBEM2023.COB2023-1843
Abstract
Linear stability theory is used to investigate the hydrodynamic stability of viscoelastic jet flows, particularly two-dimensional, planar, incompressible, submerged jets discharging from a nozzle into a medium of the same fluid as the jet. The constitutive stress relations considered in this study are those of the Oldroyd-B and Giesekus models. This work aims to provide additional information on the stability of viscoelastic jets, with a specific focus on absolute instability. The study involves comparing the spatial growth rates of the instability modes and analyzing the frequency ranges associated with unstable behavior. Additionally, an examination of the dimensionless parameters that contribute to absolute instability is conducted. It has been observed that the mobility parameter, denoted as $\alpha_G$, in the Giesekus model has a damping effect on absolute instability. However, increasing this parameter leads to a broader range of instabilities.
Keywords
Jet flow, Oldroyd-B fluid, Giesekus fluid, Linear Stability Analysis
