Dr B Saravanan Research Associate, ISO-40 Department of Engineering University Of Cambridge, UK Did B.Tech at IIT Madras, PhD in France Despite decades of research, thermo acoustic instability remains one of the biggest problems facing manufacturers of gas turbines. In these devices, the acoustics is usually linear, but the flame’s heat-release response to incident perturbations is highly nonlinear. The overall thermo acoustic system is therefore expected to behave like a coupled nonlinear dynamical system. In order to understand the nonlinear interactions between self-and forced excited premixed flames, we have carried out a detailed study using a laboratory-scale combustor containing a swirl-stabilized turbulent premixed flame. This presentation will touch upon the preliminary results obtained from the experimental investigation. In particular, the off-resonance frequency locking effect and the triggering of self-excited instability by forcing will be discussed.  Â