•Newly introduced approach to modeling mean heat-release rate in flames is validated.•The approach works in flamelet and thin-reaction-zone regimes of turbulent burning.•The approach predicts significant oscillations of burning velocity found in DNS. Recently, a transport equation for the mean rate of product creation in a premixed turbulent flame was derived and a joint closure relation for dominant terms in that equation was developed and validated against Direct Numerical Simulation (DNS) data obtained from weakly turbulent flames. Present communication reports results of further DNS tests of this newly introduced approach, performed using recent data computed under substantially different turbulent conditions. In particular, the ability of the approach to predict significant oscillations of the turbulent burning velocity with time is shown under conditions associated with not only the flamelet but also the thin-reaction-zone regimes of premixed turbulent burning. While such oscillations are documented in the present and other DNS studies, capabilities of other models of premixed turbulent combustion to reproduce this challenging phenomenon have not yet been demonstrated in the literature.