Turbulent flame speed based on the mass flow rate: Theory and DNS

摘要

Starting with an integral formulation of average mass flow rate through an ensemble of isotherms constituting a statistically planar, turbulent premixed flame, a scaling for the corresponding turbulent flame speed is derived without invoking Damkiihler's hypotheses. Major approximations and interim results are validated using a large Karlovitz number, unity Lewis number, Direct Numerical Simulation (DNS) dataset of n-heptane/air mixture, computed with reduced chemistry. A length scale quantifying the fluctuation distance of the isotherms within the premixed flame structure is analysed. (c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved.