INFLUENCE OF FLOW BEHAVIOR IN THE COMBUSTOR ON COMBUSTION INSTABILITIES PERFORMANCE OPERATING ON HOMOGENEOUS FUEL - AIR MIXTURES

摘要

The paper describes the investigations results how the gas flow patterns in the combustor effect high frequency and low frequency combustor instabilities, gas dynamics of the flow, recirculation zones dimensions and lean flame out limits. Two versions of combustor configurations are described: with the abrupt divergence of the channel and with an inlet conical diffuser. Gas flow instabilities had been investigated in the central recirculation zone without any chemical reactions. Combustion instability modes had been investigated in different configurations of the combustor. The combustion instability model in which a role of a feed back mechanism is performed by hydrodynamic gas flow instability in the central recirculation zone is suggested. Modification of the combustor with a conical diffuser with the suggested model of the hydrodynamic combustion instability taken into account made it possible to settle the instability problem for the given combustor.