Measurement of the turbulence in a gaseous rocket combustion chamber

Abstract

An experimental method was used to determine the intensity of turbulence and the Lagrangian correlation coefficient in a GH 2-GOX rocket combustion chamber. The method consisted of injecting a tracer gas at an upstream point on the centerline of the combustion chamber while taking gas samples along a diameter at a downstream station. The gas samples were analyzed to determine the spreading of the tracer gas concentration. The turbulence parameters were determined from the tracer gas concentration data using a combination of Taylor's turbulent diffusion theory and Gosman's numerical method for solving the conservation equations. Taylor's theory was extended to consider the inhomogeneity of the turbulence field in the axial direction of the combustion chamber. The Lagrangian correlation coefficient was approximated by an exponential function. The results indicate that the intensity of turbulence varies from a maximum of approximately 15% near the injector to 4% at the nozzle entrance. The Lagrangian correlation coefficient decreases very rapidly as the dispersion time difference increases.