Application of the Time-Domain Impedance Boundary Condition to Large-Eddy Simulation of Combustion Instability in a Shear-Coaxial High Pressure Combustor

摘要: The time-domain impedance boundary condition (TDIBC) is used within a large-eddy simulation (LES) framework to investigate self-sustained longitudinal combustion instability in the Continuously Variable Resonance Combustor (CVRC) rig, high-pressure, shear-coaxial injector combustor studied experimentally at Purdue University. A modified version of constant mass characteristic account for oxidizer inlet, which truncated and therefore becomes an approximation full inlet. Both linear non-linear models inlet reflection coefficients are developed compared against LES. CVRC rig exhibits different amplitude levels pressure oscillation depending on length injector, thus, offers range conditions evaluate use TDIBC. with 2.05 cm simulate equivalent three lengths 9 cm, 12 14 known exhibit semi-stable, unstable highly behavior, respectively. results LES that explicitly resolve post without impedance. It shown prediction by coefficient model much better than model. Further analysis carried out highlight strengths limitations