The analysis of the chemical behavior of the working fluid in gas turbines is usually restricted to the combustion chamber sections. However, the current trend toward higher Turbine Inlet Temperatures (TIT), in order to achieve improved thermal efficiency, will invalidate the assumption of frozen composition of the gases in the first stages of the expansion process. It will become necessary to consider the recombination reactions of the dissociated species, resulting in heat release during expansion. In order to quantify the influence of this reactivity on the performance of high TIT gas turbines, a one-dimensional model of the reactive flow has been developed. Preliminary results were reported in a previous paper. The authors concluded that, in the case of expansion of combustion gases in a subsonic static uncurved distributor nozzle, the residual reactivity must be taken into account above a temperature threshold of around 2000 K. The present study extends these results by investigating the reactive flow in a complete multistage turbine set, including a transonic first-stage nozzle. A key result of this study is that heat release during the expansion process itself will be considerable in future high-temperature gas turbines, and this will have significant implications for turbine design techniques. Furthermore, we show that, at the turbine exit, the fractions of NO and CO are very different from the values computed at the combustor outlet. In particular, NO production in the early part of the expansion process is very high. Finally, the effects of temperature fluctuations at the turbine inlet are considered. We show that residual chemical reactivity affects the expansion characteristics in gas turbines with TITs comparable to those attained by modern high-performance machines.

Chase, M. W., Davies, C. A., Downey, J. R., Frurip, D. J., McDonald, R. A., and Syverud, A. N., 1985, Janaf Thermo-Chemical Tables, 3rd ed., Am. Chem. Soc., Am. Inst. of Physics, Nat. Bureau of Standards.
CISI-Ingenierie, 1989, “Neptunix—ODE Solver and Model Description,” Division Ge´nie Logiciel et Application, 3 rue Lecorbusier, SILIC 232, F-94528 Rungis.
Cohen, H., Rogers, G. F. C., and Saravanamuttoo, H. I. H., 1987, Gas Turbine Theory, 3rd ed., Longman Scientific & Technical.
de Piolenc, M., 1992, “Latest Jet Engine Technology Could Radically Change Industrial Designs,” Gas Turbine World.
Edelman, R. B., and Fortune, O. F., 1969, “A Quasi-Global Chemical Kinetic Model for the Finite Rate Combustion of Hydrocarbon Fuels With Application to Turbulent Burning and Mixing in Hypersonic Engines and Nozzles,” presented at the AIAA 7th Aerospace Sciences Meeting, New York.
Goldman, L. J., and Seasholtz, R. G., 1982, “Laser Anemometer Measurements in an Annular Cascade of Core Turbine Vanes and Comparison With Theory,” NASA Technical Paper 2018.
Gras, J. M., 1992, “Mate´riaux de Turbines a` Combustion—Evolution des Tendances,” EDF-DER, Service IPN, De´p. SID, F-92141 Clamart.
, and
, “
Residual Reactivity of Burned Gases in the Early Expansion Process of Future Gas Turbines
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
, pp.
Magre, P., Collin, G., Ansart, D., Baudouin, C., and Bouchie, Y., 1991, “Mesures de Tempe´rature par DASC et Validation d’un Code de Calcul sur Foyer de Turbore´acteur,” Technical report, ONERA (Chaˆtillon, France) and SNECMA (Villaroche, France). Third European Forum on Aeronautic Propulsion Systems EPF 91, Nov., Paris, France.
Mencherini, A., 1993, “Alcuni Aspetti nella Simulazione della Combustione/Espansione nelle Turbine a Gas,” Tesi di Laurea, Universita` di Firenze, Italy.
J. A.
, and
C. T.
, “
Mechanism and Modelling of Nitrogen Chemistry in Combustion
Prog. Energy Combust. Sci.
, Vol.
, pp.
Schuetz, H., and Muehleck, P., 1991, “Influence of the Flight Trajectory on the Exhaust Gas Composition of a H2-Fueled Air-Breathing Ramjet Engine,” Orbital Transports: Meteorological, Technical and Chemical Aspects, Springer Verlag, H. Oertl and H. Ko¨rner, eds., 3rd Aerospace Symposium Braunschweig, Aug. 26–28.
Szanca, E. M., Schum, H. J., and Hotz, G. M., 1974, “Research Turbine for High-Temperature Core Engine Application,” NASA Technical Note d-7557, Washington DC.
Zucrow, M. J., and Hoffman, J. D., 1977, Gas Dynamics—Multidimensional Flow, Wiley, New York.
This content is only available via PDF.
You do not currently have access to this content.