READ ME File for 'Dataset for Interaction and vectoring of parallel rectangular twin jets in a turbulent boundary layer'

Dataset DOI: https://doi.org/10.5258/SOTON/D1781

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     : Interaction and vectoring of parallel rectangular twin jets in a turbulent boundary layer
JOURNAL   : Physical Review Fluids
PAPER DOI :

The dataset is split into four parts: (i) Angles, (ii) TKE, (iii) Tau and (iv) SPIV,
and has been used to plot the following figures in the paper:
Fig. 4  : Boundary layer-subtracted streamwise velocity (u) contour plots for twin jets evolving during the blowing part for s/d = 2, 6.5 and 13.
Fig. 5  : Vorticity-signed swirling strength contour plots for twin jets evolving during the blowing part for s/d = 2, 6.5 and 13.
Fig. 6  : Vorticity-signed swirling strength contour plots demonstrating the influence of orifice spacing on the vectoring behaviour of twin jets.
Fig. 7  : Variation of (a) vectoring angle and (b) yawing offset with streamwise location for differing phase difference between the twin jets.
Fig. 8  : Variation of normalised turbulent kinetic energy with streamwise location as phase difference between jets is varied.
Fig. 9  : Variation of spanwise- and time-averaged total shear stress as the phase difference and orifice spacing between the jets are varied.
 
The zip file 'Data.zip' contains the following:
1. Angles : The angles mat file is a structured file with two variables, Gamma and Chi. As specified in the paper, Gamma represents the vectoring angle (in degrees)
            while Chi represents the yawing offset normalised by the slot length. Both Gamma and Chi are 5 x 4 matrices with rows representing the downstream locations
            (x/delta = 0, 0.5, 1, 3 and 6 in ascending order) while the columns represent the phase difference between the jets (Beta = 12, 78, 108 and 138 deg in ascending order).          

   The Angles data is used to plot figure 7.


2. TKE    : The TKE mat file is a structured file with four variables, d2, d6_5, d13 and x.
            d2, d6_5 and d13 contain the normalised TKE value corresponding to a separation distance between the orifices of 2, 6.5 and 13 mm respectively.
            All three are 5 x 6 matrices with rows corresponding to the downstream location (x/delta = 0, 0.5, 1, 3 and 6 in ascending order) while the columns represent the phase difference between the jets (Beta = 0, 12, 78, 108, 138 and 168 deg in ascending order).
            x is a 5 x 1 matrix containing the normalised downstream locations.

   The TKE data is used to plot figure 8.


3. Tau    : The TKE mat file is a structured file with four variables, d2, d6_5, d13 and Y.
            d2, d6_5 and d13 contain the spanwise and time averaged total shear stress for the separation distance between the orifices corresponding to 2, 6.5 and 13 mm respectively.
            All three are 5 x 1 cells with each row of the cell corresponding to a downstream location (x/delta = 0, 0.5, 1, 3 and 6 in ascending order).
            Each cell (downstream location) contains a 6 column matrix with each column corresponding to the total shear stress profile for varying phase difference between the jets (beta). Columns 1, 2, 3, 4 ,5 and 6 correspond to beta of 0, 12, 78, 108, 138 and 168 deg respectively.
            Y is a matrix which contains the normalised wall-normal location of the profile.

   The Tau data is used to plot figure 9.


4. SPIV   : The folder 'SPIV' contains the phase-locked stereoscopiv PIV flowfields used to plot figures 4, 5 and 6. 
            The folder is divided into subfolders according to the downstream location, the orifice separation distance and the phase difference between the jets of the case. 
            One actuation cycle was divided into 8 phases (phi) and PIV flowfield for the blowing part (phi = 0 - 135deg) is provided.
            Each .mat file is named accordingly, e.g., 0x_2d_0beta_phi90.mat corresponds to the case with downstream location of 0 delta, separation distance of 2 mm, phase
            difference between jets of 0 degrees and phase-locked at 90 degrees. Each .mat file contains the following:

   	DESCRIPTION                                             VARIABLE       UNITS
        - Mean streamwise velocity                              Um             (m/s)
        - Mean wall normal velocity                             Vm             (m/s)
        - Mean spanwise velocity                                Wm             (m/s)
        - Spanwise coordinates                                  Z              (mm)
        - Wall normal coordinates                               Y              (mm)
        - Boundary layer properties upstream of orifices        BL              -
          Note: BL is a structure which contains the spanwise average streamwise velocity profile (Um) and the corresponding wall normal location of each point (Y). 
            
   The SPIV data is used to plot figure 4, and obtain the swirling strenght data for figures 5 and 6.

Date of data collection: March - June 2017

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: March, 2021