The role of primary jet injection on the aerothermal structure and overall performance of a model gas turbine combustor is addressed in an experimental study. The impact of momentum ratio between the primary jets and the swirl air as well as the relative position of the jet row to the swirler injection plane are investigated in a combustor operated on propane at atmospheric pressure. The aerodynamic and thermal fields are characterized using laser anemometry and a thermocouple probe respectively. Species concentrations are acquired at the exit plane via extractive probe sampling. Four regimes are identified that describe the degree of interaction of the primary jets with, the swirl-induced recirculation zone. For each regime, the degree of jet penetration and entrainment in the recirculation zone and, as a result, the aerothermal structure of the dome region are substantially different. © 1991 Combustion Institute.

The role of the primary jets in the aerothermal behavior and overall performance of a gas turbine combustor is explored through an experimental study. The study is performed in a model laboratory combustor that possesses the essentialfeatures of practical combustors. The test bed is designed to accommodate opticalaccess for laser diagnostics and overall flow visualization, and is capable of incorporating variable inlet geometries. In the present case, the combustor is operated on JP-4 at atmospheric pressure. A parametric variation in the number of jets per row and axial location of the jet row is performed. The aerodynamic and thermal fields are characterized using laser anemometry and a thermocouple probe, respectively. Species concentrations are acquired via extractive probe sampling. The results demonstrate the importance of primary jet location with respect to the dome swirler. The percent mass recirculated into the dome region, as well as the overall uniformity of mixing and combustion efficiency, are substantially influenced by jet row location. The momentum ratio of the incoming primary jet stream to that of the approaching crossflow of reacting dome gases has a direct impact on the mixing patterns as well. An increase in the number of primary jets leads, in the present case, to more uniform mixing. © 1992 ASME.