Coupling between combustion oscillations and acoustic pressure oscillations can lead to large-amplitude pressure oscillations within the combustor. This interaction between combustion and acoustics is an area of active research in the application of LPM combustion to gas turbines used for power generation. Experiments conducted using the test rig were converted into three-dimensional models to better study the combustors transient behavior. The CRAY T3E, a supercomputer housed in the Pittsburgh Supercomputing Center, was used to develop the 3D models. Using the computer s platform, multiple simulations were performed in a short time frame to study the effects of swirling vane position, nozzle velocity, and fuel-air ratio on flow and combustion.
Preliminary results suggest that careful placement of the swirl vanes enhances combustion stability.
Simulation reveals that swirl vane location and flow conditions affect the flame s shape and orientation within the combustor, which affect the time delay between fuel injection and the point where fuel reacts in the flame. This time delay determines when combustion and pressure oscillations occur, potentially causing turbine problems. Additional study is underway at FETC to measure the time delay in the combustor. Combined with experimental data, these simulations may identify a design approach that will enhance stability.