A Numerical Study of Chemically Reactive Flow of Hot Combustion Gases in a First-Stage Turbine Nozzle

Abstract

Current progress in gas turbine performance is achieved mainly by increasing the turbine inlet temperature. At high temperature levels (>2000K), the hot combustion gases can no longer be considered as chemically inert, and it becomes important to account for dissociation and recombination reactions occurring not only in the combustion chamber but also within the expanding gas stream in the turbine. In this paper, the authors present a two-dimensional numerical study of chemically reactive flow of hot combustion gases through the first guide vane of a gas turbine. For this initial study, simplified boundary conditions are assumed: blade cooling air mixing is neglected, the blade wall temperature is assigned a fixed value, and uniform inlet conditions are assumed. This study investigates the effect of turbulence on chemical reaction kinetics and presents pollutant emission levels at the nozzle exit. Particular attention is also focussed on chemical reactivity near the pressure and suction sides of the turbine guide vane blades.