An Experimental Data Base for the Computational Fluid Dynamics of Combustors

A model axisymmetric gas-fired can combustor is used to (1) establish the sensitivity of the aerodynamic and thermal structure to inlet boundary conditions, and (2) thereby establish a demanding and comprehensive data base for the computational fluid dynamics of combustors. The parameters varied include fuel injection angle and inlet configuration. Detailed characterizations of the aerodynamic and thermal flowfields are accomplished using two-color laser anemometry and a Type R thermocouple, respectively. Specific results show that the reactor operation is especially sensitive to modest changes in both the inlet geometry and fuel injection angle. For example, the addition of a step expansion significantly alters the size and location of the swirl-induced toroidal recirculation zone. Further, the use of the step expansion, in combination with the injection of fuel matched to the swirl aerodynamics, transforms the recirculation zone to an on-axis structure. The addition of a divergent inlet further enhances the effectiveness of the backmixing by enlarging the recirculation zone. The data base developed for these conditions is carefully documented and provides a comprehensive challenge for the computational fluid dynamics of combustors.