Further Velocity Measurements in a Turbulent Diffusion Flame with Moderate Swirl

Abstract

This paper is a sequel to previously published work (Stårner and Bilger 1988) on a swirling turbulent hydrogen diffusion flame in a co-flowing stream. Improved nozzle design and altered boundary conditions have resulted in much stronger influence of the swirl, whilst maintaining the simple chemistry and the parabolic character of the flow. A new set of measurements is presented, including all components of the stress tensor. Results show a shortened, broaded flame with inverted excess velocity profile, marked turbulence suppression and a reduction in the u-v stress correlation coefficient in downstream profiles. Estimates of source terms in the transport equations for turbulence kinetic energy and u-v stress indicate significant suppression of both quantities by the velocity pressure-gradient correlations. This set of data is intended as a detailed base for direct testing of turbulence submodels in swirling flows.