EPTT 2022

13th Spring School on Transition and Turbulence

Linear stability analysis of the double Tsuji burner

Submission Author: Matheus P. Severino , SP
Co-Authors: Matheus P. Severino, Mariovane Donini, Fernando Filho Fachini, Leandro Franco de Souza
Presenter: Matheus P. Severino

doi://10.26678/ABCM.EPTT2022.EPT22-0023

 

Abstract

Diffusion flames are sensitive to the flow field and, conversely, the flow field is influenced by heat sources - one of the main causes of hydrodynamic instability. In practice, hydrodynamic instability can be either detrimental or beneficial: in an industrial context, for example, hydrodynamic instabilities can lead to harmful conditions for equipment if not correctly predicted and controlled. In contrast, hydrodynamic instabilities generally enhance properties that depend on the contact area or local gradients, such as mixing and reaction rates, which ultimately leads to turbulence. Therefore, the analysis of the stability of chemically reacting flows is crucial for the development of combustion systems. In this analysis, an infinitely long cylindrical burner is assumed, which ejects gaseous fuels radially and uniformly into the ambient. The burner is located in the centre of the impinging flows that transport gaseous oxidiser from the ambient atmosphere to the burner. This configuration is called the double Tsuji burner, derived from the classic Tsuji burner. The main feature of the flame established in this setup - i.e., the double Tsuji flame - is the representation of different flame regimes, from the counterflow regime (close to the vertical axis of symmetry) to the coflow regime (close to the horizontal axis of symmetry), with continuous variations between them. The aim of this work is to determine the hydrodynamic stability of the flow generated by the double Tsuji flame using a (local) linear stability analysis, which provides physical insights and also serves as a starting point for more detailed analyses. The study shows that the flow is stable in all cases investigated, which is physically consistent with the conditions considered.

Keywords

hydrodynamic stability, Linear Stability Analysis, interaction between radial and impinging flows, double Tsuji burner, double Tsuji flame

 

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