Anchored CCD for Gas Turbine Combustor Design and Data Correlation

Abstract

Correlations based on design database, combined with multidimensional computational combustion dynamics (CCD) models are used in the combustion design process. However, because of limitations in the current turbulent combustion models, numerics, and boundary conditions, CCD has provided mainly qualitative trends for aerothermal performance, emissions, and liner wall temperature levels and gradients. To overcome these deficiencies, hybrid modeling approaches have been proposed to analyze existing combustors. A typical hybrid modeling approach combines empirical and semianalytical correlations with CCD to give quantitatively accurate predictions of NOx, CO, HC, smoke, lean blowout, ignition, pattern factor, and liner wall temperatures. An alternate approach, anchored CCD, is described in this paper. First, the models were anchored with one of the five modern turbopropulsion engine combustors. The anchored models were then run for the other four combustors. The predicted results correlated well with measured NOx, CO, HC, LEO, and exit temperature quality data, demonstrating a broader applicability of the anchored method. The models were also used for designing a new combustion concept. The pretest prediction agreed well with sector rig data from development hardware, showing the feasibility of using the anchored methodology as a design tool.