Numerical Investigation of the Influence of Flow Parameters Nonuniformity at the Diffuser Inlet on Characteristics of the GTE Annular Combustion Chamber Available to Purchase

Parameters at a combustion chamber’s inlet significantly vary in an aircraft engine’s transient states of operation. At the same time, there is a significant spatial heterogeneity of flow parameters at a diffuser inlet of a combustion chamber, which is defined by nature of flow in a compressor and an individual for each mode of operation of a specific gas generator. In this paper presented a study of an influence of radial and circumferential nonuniformities of flow parameters on characteristics of a combustion chamber. Multi spray for annular combustion chamber with two rows of burner is considered. Z-shaped sector, which contains two nozzles of outer and two nozzles of inner row, was selected as the calculated domain. Calculations were carried out in ANSYS Fluent 14.5 software package with an implementation of cluster analysis. Nonuniformity at a diffuser inlet was set as fifth degree polynomial, which was derived from a numerical simulation of a compressor. As a result it was established, that radial nonuniformity of flow parameters at an inlet of a combustion chamber influences on characteristics of a combustion chamber. A stretched shape of velocity profile contributes to higher air flow dynamic pressure on dome than using uniform profile air velocity. At that, local equivalents ratio excess are changing, and consequently, sizes and location NO_x production zones are changing as well. The residual rotation of flow from the compressor leads to a lesser effect on total pressure drop and air distribution in flame tube. The obtained results showed that, during a design of a combustion chamber, it is necessary to take into account nonuniformity of parameters’ distribution at its inlet.