A Second Generation Swirl-Venturi Lean Direct Injection Combustion Concept

A low-NOx aircraft gas turbine engine combustion concept was developed and tested. The concept is a second generation swirl-venturi lean direct injection (SV-LDI) concept. LDI is a lean-burn combustion concept in which the fuel is injected directly into the flame zone. Three second generation SV-LDI configurations were developed. All three were based on the baseline 9-point SV-LDI configuration reported previously. These second generation configurations had better low power operability than the baseline 9-point configuration. Two of these second generation configurations were tested in a NASA Glenn Research Center flametube; these two configurations are called the flat dome and 5-recess configurations. Results show that the 5-recess configuration generally had lower NOx emissions than the flat dome configuration. Correlation equations were developed for the flat dome configuration so that the landing-takeoff NOx emissions could be estimated. The flat dome landing-takeoff NOx is estimated to be 87–88% below the CAEP/6 standards, exceeding the ERA project goal of 75% reduction.