Experimental Investigation of Axisymmetric, Turbulent, Annular Jets Discharged Through the Nozzle of the SPP1980 SpraySyn Burner Under Isothermal and Reacting Conditions

Abstract The present study contributes to the characterization of the complex flow fields that arise from annular turbulent non-reacting and reacting jets dispersed through the SPP1980 SpraySyn-burner. The SpraySyn-burner is a new lab-scale standard burner to study the production of functional materials by flame spray pyrolysis. Velocity measurements of axisymmetric turbulent annular jets issued through the nozzle of the SpraySyn-burner are performed with 2D-2C particle image velocimetry. Investigated cases include a turbulent annular free jet and turbulent annular jets weakly confined by co-flowing low-momentum streams under non-reacting and reacting conditions. The results of an isothermal case are validated with hot-wire anemometer measurements and compared with large eddy simulations. Fields of mean velocity and its standard deviation, as well as their centreline profiles are presented for all cases and compared to previous research studies of round, annular and co-axial jets. Significant changes in the flow velocity dynamics between non-reacting and reacting cases are discussed. Additionally, normalized radial profiles of axial mean velocity and Reynolds stresses are related to self-similarity theories. The data reveal that the results of self-similarity profiles are in good agreement with those found in the literature. Meanwhile, the self-similar profiles of Reynolds stresses from the studied annular jets asymptotically converge to unique self-similar profiles with differences in magnitudes due to variations in the initial conditions, boundaries and jet history. The present results are primarily useful for providing validation data for computational simulations that model the intricate droplet-particle formation using the SpraySyn-burner.