  This study investigates the effects of curvature on the local heat release
rate and mixture fraction during turbulent flame-wall interaction of a lean
dimethyl ether/air flame using a fully resolved simulation with a reduced
skeletal chemical reaction mechanism and mixture-averaged transport. The region
in which turbulent flame-wall interaction affects the flame is found to be
restricted to a wall distance less than twice the laminar flame thickness. In
regions without heat losses, heat release rate and curvature, as well as
mixture fraction and curvature, are negatively correlated, which is in
accordance with experimental findings. Flame-wall interaction alters the
correlation between heat release rate and curvature. An inversion in the sign
of the correlation from negative to positive is observed as the flame starts to
experience heat losses to the wall. The correlation between mixture fraction
and curvature, however, is unaffected by flame-wall interactions and remains
negative. Similarly to experimental findings, the investigated turbulent
side-wall quenching flame shows both head-on quenching and side-wall
quenching-like behavior. The different quenching events are associated with
different curvature values in the near-wall region. Furthermore, for medium
heat loss, the correlations between heat release rate and curvature are
sensitive to the quenching scenario.

Fluid Dynamics