Development of a Reduced Smoke Combustor for the JT3D Engine

A new combustor configuration having substantially lower smoke emission characteristics is now in the final stages of development for the JT3D commercial aircraft turbofan engine. In addition, the low-power emissions of hydrocarbons and carbon monoxide are considerably reduced. This burner configuration utilizes many of the features developed in the JT8D turbofan engine smoke reduction program; however, it was also necessary to incorporate air-assist fuel injection nozzles to achieve smoke levels below the EPA regulation requirement of 25. Correction of a nozzle carbon formation problem and further durability testing must be accomplished before this combustor can be released for in-service commercial airline controlled-service use evaluation.