Mixing and Combustion in Vortex Dominated Combustors with Distributed Air- and Fuel-Injection

摘要

Measurements of temperature, velocity and emissions were performed in two trapped vortex combustor configurations, and several strategies for improving key performance metrics (e.g., circumferential uniformity in temperature and NOx emissions) were examined. The measurements show that introducing swirl with the primary cavity air reduces NOx emissions, extends the Lean Blow Out (LBO) limit and decreases circumferential non- uniformity in the temperature. With the inner-cavity configuration, LBO values as low as 0. 1 and single-digit NOx were achieved. With the outer-cavity configuration, LBO occurred at 0.3. Computations performed indicate that the cavity vortex has a toroidal donut shape, and has large scale dynamics. Distributed micro-scale fuel injectors were fabricated as part of this effort, and have the potential for generating an uniform dispersion of small droplets desirable for improved combustion characteristic& Temperature-actuated bi-morph valves were also develop%d for control of dilution air and local stoichiometry.