Scalar characterisations of three-dimensional shock-flame interactions: similarity and inhomogeneity

ABSTRACT

Three-dimensional shock-flame interactions are simulated by the ninth-order WENO scheme to study the characterisations of scalar under Richtmyer-Meshkov instability (RMI) with reaction. Initially, a planar incident shock with Ma = 1.7 accelerates the single-mode diffusive flame interface with initial wavelength 4 mm and amplitude 0.4 mm from the reactant C₂H₄+3O₂+4N₂ medium with temperature 293 K and pressure 13.3 kPa; then the transmitting shock branch during incident shock-flame interaction is reflected at the end boundary to form a reflected shock which disturbs the flame interface again. The reflected shock-flame interaction will form transmitting and reflecting shock branches where the reflecting branch reflects at the end boundary and accelerates the flame interface again. During successive interactions between flame interface and shocks, a large range of flow is generated. Physical processes in the flame interface are examined related to the evolution of reactant density and internal energy density, including convection, molecule diffusion, reaction, pressure-dilatation, and heat conduction. Similarity in scalars and velocity is examined in both spatial and spectral spaces and inhomogeneity related to similarity is provided.

KEYWORDS:

• Scalar
• similarity
• inhomogeneity
• shock-flame interaction

ORCID

Dandan Wang http://orcid.org/0000-0002-2898-8159

Additional information

Funding

This work was supported by the National Natural Science Fundation of China  [grant number 11872213].