Avoiding combustion instabilities in a reheat combustor

摘要

The procedure, for use with a bi-flow turbojet engine, consists of detecting experimentally during engine tuning the vibration zones due to after-burning as a function of the engine and after-burner operation, and developing laws for regulating fuel richness levels for each flow to eliminate the detected vibration. The vibration zones are detected as a function of primary and secondary fuel richness functions based on maximum pressure in the after-burner chamber, and at least one regulating law is developed to eliminate the vibration zones in conditions corresponding to the maximum pressure.