On integrated experimentation and simulation of a counter-turning swirling mixer, part I: Experimentation

Abstract

Success in developing advanced combustor concepts relies significantly on achieving rapid and uniform mixing of fuel with combustion air through a fuel/air preparation device called mixer. To guide the design and development of gas turbine combustor expeditiously, detailed understanding of the flow characteristics and performance of a mixer of interest is essential. Leveraging recent advances in computational fluid dynamics (CFD) and diagnostic techniques, a series of studies have been initiated to develop and calibrate best practices on integrated experimentation and simulation for two generic families of mixers, namely for lean-direct injection and rich-dome combustors. Here, a set of three papers have been prepared to summarize our research activities on a mixer relevant to rich-dome combustors. This Part I paper presents the method by which a high-quality Time-Resolved Particle Image Velocimetry (TR-PIV) two-dimensional velocity dataset is established for a counter-turning multi-swirlers (CTS) mixer. The non-reacting flow field characteristics at 3% pressure drop across this CTS mixer are quantified by collecting more than 10,000 image pairs captured and processed via a high-accuracy sub-pixel adaptive correlation algorithm. Mean and root-mean-square velocity profiles are presented along with quantification of critical flow structure metrics. Proper Orthogonal Deconvolution structure analysis is also presented for the dominant modes. A full description of the uncertainty analysis of the TR-PIV velocity data is further provided, as is a detailed convergence study. The dataset is determined to be of sufficient quality to be used for quantitatively anchoring CFD simulations as summarized in our two companion papers Part II (Reynolds-Averaged Navier-Stokes models) and Part III (Large Eddy Simulation).