Instabilities in the near wake of a rod with an anchored flame

Turbulent combustion can involve the interaction of flame dynamics, flow structures and acoustic instabilities and many problems remain to be solved. A study of the anomalous `intrinsic´ instability of premixed flames anchored to a rod shows that this instability results in fact from acoustic forcing of the downstream wake. This is shown by tomographic visualizations and by correlations between pressure fluctuations in the combustion chamber and various signals issuing from laser tomography, laser anemometry and deflectometry in the near wake