Computational Investigation of Combustion Instabilities in a Laboratory-Scale LDI Gas Turbine Engine
Abstract
Self-excited combustion instabilities in a lean direct injection (LDI) gas turbine combustor are computationally investigated. The model LDI combustor under study was developed to produce combustion dynamics on demand using a single LDI element in an axisymmetric combustor. Three simulation cases for this combustor are considered: non-reacting and reacting flow in an acoustically open combustor and reacting flow in an acoustically closed combustor. We studied the dynamic flow features in the LDI combustor for both cases and investigated the important modes using a dynamic mode decomposition method. Precessing vortex core (PVC) instabilities are indicated as the critical hydrodynamic mode and lead to strong spray and flame response. In the acoustically close chamber simulation, we were able to capture self-excited combustion instabilities and the dominant modes from simulations, which qualitatively agree with the experimental results. The appearance of pressure peaks in both simulation and experiment at about 1400 Hz corresponding to the 4L acoustic mode and at 6000 Hz are explained by the nonlinear coupling of the PVC and acoustics modes and the associated feedback loop.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2013
- Accession Number
- ADA596107
Entities
People
- Changjin Yoon
- Cheng Huang
- Rohan Gejji
- Venkateswaran Sankaran
- William E Anderson
Organizations
- Air Force Research Laboratory