Velocity and Turbulence Measurements in Model Gas-Turbine Combustion Chambers and Comparison With A Model Calculation

Abstract

Detailed measurements of the flow properties in gas-turbine combustion chambers are desirable to improve combustion stability, pollutant emissions, and the temperature profile at the chamber exit. Many investigators have studied flow fields in gas-turbine combustors experimentally and theoretically. Most of the experimental investigations which have provided useful velocity information, however, have been limited by the combustor geometries and the techniques of instrumentation. Laser Doppler anemometry (LDA) is useful for obtaining information not only of the time-averaged flow velocity but also of turbulent fluctuations and their cross-correlations. Green and Whitelaw obtained measurements with LDA and calculations with a two-equation turbulence model for the turbulent flow of water both in an axisymmetric geometry [1], and in a geometry which was greatly simplified but provided three-dimensional flow patterns close to those found in real combustors [2], they measured mainly mean axial velocity, and did not measure the three velocity components. Toral and Whitelaw [3] reported profiles of three components of mean velocity for the sector configuration based on the annular combustor which allows access to the whole flow field. Heitor and Whitelaw [4] measured axial and tangential velocity components and the corresponding Reynolds stresses of the isothermal and the combusting flows in a model can-type combustion chamber which closely resembles real combustors, although the measurement was Limited by optical access to the axis of the primary and dilution holes. Koutmos et al. [5] reported three components of mean velocity and turbulence intensities in a water model gas-turbine combustor.