Articles techniques et présentations

The thermoacoustic combustion instabilities are complex phenomena that may occur in steady flow combustion systems that are aboard of, e.g., rocket engines or gas turbines. The phenomena involve the interaction of chemical reactions with fluid-dynamic and propagation of pressure waves in the combustion chamber. Combustion instabilities may lead to a stable condition (known as “limit-cycle”) characterized by pressure oscillations so intense that the operation of the engine cannot be continued.
In order to study this phenomenon, the propagation of the pressure oscillations by means of inhomogeneous wave equation and considering the heat release fluctuations produced by the flame dynamics as source term. This simulation can be carried out in COMSOL Multiphysics through the Pressure Acoustic Module (acpr). In the present paper the methodology adopted in COMSOL to simulate the non-linear dynamics is shown and the results of the application to a simple cylindrical combustor are reported