DNS study of the bending effect due to smoothing mechanism
Artikel i vetenskaplig tidskrift, 2019

Propagation of either an infinitely thin interface or a reaction wave of a nonzero thickness in forced, constant-density, statistically stationary, homogeneous, isotropic turbulence is simulated by solving unsteady 3D Navier–Stokes equations and either a level set (G) or a reaction-diffusion
equation, respectively, with all other things being equal. In the case of the interface, the fully developed bulk consumption velocity normalized using the laminar-wave speed SL depends linearly on the normalized rms velocity u'/SL. In the case of the reaction wave of a nonzero thickness, dependencies of the normalized bulk consumption velocity on u'/SL show bending, with the effect being increased by a ratio of the laminar-wave thickness to the turbulence length scale. The obtained bending effect is controlled by a decrease in the rate of an increase AF in the reaction-zone-surface area with increasing u'/SL. In its turn, the bending of the AF(u'/SL)-curves stems from inefficiency of small-scale turbulent eddies in wrinkling the reaction-zone surface, because such small-scale wrinkles characterized by a high local curvature are smoothed out by molecular transport within the reaction wave.

reaction waves

reaction surface area

molecular transport

direct numerical simulations

turbulent consumption velocity

bending effect

turbulent reacting flows

Författare

Rixin Yu

Lunds universitet

Andrei Lipatnikov

Chalmers, Mekanik och maritima vetenskaper, Förbränning

Fluids

2311-5521 (eISSN)

Vol. 4 1 1-13 31

Fundament

Grundläggande vetenskaper

Ämneskategorier

Strömningsmekanik och akustik

DOI

10.3390/fluids4010031

Mer information

Senast uppdaterat

2019-08-19