READ ME File for 'Dataset for Scalings for rectangular synthetic jet trajectory in a turbulent boundary layer' Dataset DOI: 10.5258/SOTON/D1679 ReadMe Author: Girish K. Jankee, University of Southampton [ORCID ID: 0000-0002-9178-1070] This dataset supports the publication: AUTHORS : Girish K. Jankee and Bharathram Ganapathisubramani TITLE : Scalings for rectangular synthetic jet trajectory in a turbulent boundary layer JOURNAL : Journal of Fluid Mechanics PAPER DOI :doi:10.1017/jfm.2020.1142 The dataset is split into four parts: (i) Data.zip, (ii) AR3.zip, (iii) AR6.zip and (iv) AR12.zip, and has been used to plot the following figures in the paper: Fig. 3 : Illustration of the use of the velocity deficit to extract the trajectory for case 7. Fig. 4 : Time-averaged trajectory of a synthetic jet overlaid with the gradient of the time-averaged trajectory for case 7. Fig. 5 : Scatter plot of the coordinates of the onset of far-field for all cases in table 1. Fig. 6 : Plots of the boundary layer subtracted streamwise velocity field. Fig. 7 : Self-similarity analysis for the cases presented in Fig. 6. Fig. 8 : Trajectories for all cases which satisfy vortex interaction, in the near-field. Fig. 9 : Trajectories for all cases which satisfy vortex interaction, in the far-field. Fig. 10 : Trajectories for all cases where there is no vortex interaction in the near-field. Fig. 11 : Trajectories for all cases where there is no vortex interaction in the far-field. Fig. 12 : Far-field time-averaged trajectories for cases 7,8 and 22 which have the same momentum coefficient but differing actuation parameters and orifice dimensions. The zip file 'Data.zip' contains the following: 1. Trajectory: For all cases described in table 1 in the paper, the trajectory for each is provided in a .mat file. The .mat files are named accordingly, e.g., AR3_f100_r1 corresponds to the case for and aspect ratio of 3, an actuation frequency of 100 Hz and a velocity ratio of 1.0. Note that 05 corresponds to a velocity ratio of 0.5 and 025 corresponds to a velocity ratio of 0.25 Each .mat file contains the following: DESCRIPTION VARIABLE UNITS BL (boundary layer properties measured upstream of orifice) - Boundary layer thickness Delta (mm) - Freestream velocity Uinf (m/s) - Momemtum thickness based Reynolds number Re_theta - Near wall skin friction coefficient cf - Friction velocity Utau (m/s) - Friction Reynolds number Re_tau - Momentum thickness of boundary layer theta (m) Jet (properties of the synthetic jet actuator) - Mean centerline jet exit velocity Uj (m/s) - Length of the orifice along the majot axis l (mm) - Actuation freuqency of the synthetic jet f (Hz) Tdata (2 column matrix) - 1st column represents the x-coordinates of the jet trajectory - 2nd column represents the corresponding y-coordinates of the trajectory The trajectory data is used to plot figures 3, 4, 8, 9, 10, 11 and 12. 2. Delimitation: This folder contains a file (Delim.mat), which contains the 2D coordinates (x,y) of the location of the onset for the far-field region. The matrix has 6 columns which, each, corresponds to the following variable: DESCRIPTION VARIABLE UNITS - 1st column: Aspect ratio of orifice AR - 2nd column: Velocity ratio r - 3rd column: length of orifice along the major axis l (m) - 4th column: Frequency of actuation f (Hz) - 5th column: x-coordinate for the threshold x_thresh (m) - 6th column: y-coordinate for the threshold y_thresh (m) The delimitation data is used to plot figure 5. The zip files 'AR3.zip', 'AR6.zip' and 'AR12.zip' contain the phase-locked PIV flowfields for all the cases in table 1. For each zip file, the folder is further divided into subfolders according to the the velocity ratio of the case. One actuation cycle was divided into 12 phases (phi) and PIV flowfield for each phase is provided. Each .mat file is named accordingly, e.g., AR3_f100_r1_phi60.mat corresponds to the case with aspect ratio of 3, actuation frequency of 100 Hz, velocity ratio of 1.0 and phase-locked at 60 degrees. Each .mat file contains the following: DESCRIPTION VARIABLE UNITS - Mean streamwise velocity Um (m/s) - Mean wall normal velocity Vm (m/s) - R.M.S of the streamwise velocity fluctuations Urms (m/s) - R.M.S of the wall normal velocity fluctuations Vrms (m/s) - Streamwise coordinates X (mm) - Wall normal coordinates Y (mm) The trajectory data has been extracted from the PIV flowfields and the latter have also been directly used to plot figures 3, 6 and 7. Date of data collection: January - April 2018 Information about geographic location of data collection: University of Southampton, Southampton, UK, SO17 1BJ Licence: Creative Commonss: Attribution 4.0 (CC BY) Related projects: EPSRC Grant No. EP/L006383/1 Date: December, 2020