The model combustion chamber (KBK) is used for the investigation of direct and indirect combustion noise. The direct combustion noise is mainly caused by the temporally and spatially varying heat release inside the combustion chamber, originating e.g. in inhomogenous fuel-air mixture. The model combustion chamber can be operated in a wide parameter range (rich burn - with increased fuel rate, lean burn - with excess air - compared to the stoichiometric fuel rate, respectively) and at different thermal power settings. Optical access to the combustion zone enables the application of laser diagnostics and other imaging techniques (OH*-chemiluminescense) for the investigation of the velocity field and of the spatial distribution of the heat release.
By the acceleration of entropy or vorticity fluctuations in the outlet nozzle of the combustion chamber, there can additional noise be generated: the indirect combustion noise. For its investigation, the exhaust pipe was equipped with many ports for the connection of microphone probes, which enable a decomposition of the sound field in downstream and upstream travelling acoustic waves.
Properties of the facility