Investigation of turbulent flows via pseudo flow visualization part I: Axisymmetric jet mixing layer

Hot-wire anemometer measurements obtained in the near-field axisymmetric jet mixing layer by Glauser and George [1] are examined using a pseudo flow visualization (PFV) technique. Pseudo flow visualization is a visualization procedure used to manipulate data obtained from an array of probes to create a graphical representation of the instantaneous and fluctuating velocity components of a flow field. An indicator function was employed to identify the frequency content of each velocity-time trace, giving insight into the analysis of the visualizations. From this application, the natural shedding frequency, or preferred mode, of the large-scale structures was determined and compared with the conventional streamwise and radial spectral measurements acquired by Glauser and George [1]. Furthermore, the wavelength of the preferred mode, nondimensionalized by the jet exit diameter, was determined to be approximately 2.4, a result consistent with the work of Crowe and Champagne [2]. In Part 1 the technique is developed and discussed for the fundamental and fairly well-researched mixing layer of the axisymmetric jet. Our aim is to verify the effectiveness of PFV in the context of a well-documented flow. In Part 2, this technique is then applied to an industrial flow field, namely, the mixing region of a lobed mixer.