(a) A schematic of the plane jet nozzle, (b) time-averaged flow, and (c) laboratory dimensions. Note: U c ≡ centerline mean velocity, y 0.5 ≡ half-width (y-value where U(x, y) = 1/2U c(x)).
The jet-exit conditions defined by (a) displacement thickness (δm), momentum thickness (θm) and shape factors (H) at x/h = 0.5 reported by Deo et al. 17 (b) Momentum-based Reynolds number (Re θ) and shear layer-peak turbulent Reynolds number ( ) measured at x/h = 0.25. In part (a), δm and θm at x/h = 1 for high-AR rectangular jet of Namar and Otugen 12 are shown.
Streamwise evolution of mass flow rates m(x) normalized by bulk mass flow rate (m 0) at the exit plane.
Dependence of entrainment rates (K m ) and virtual origin (x 04/h) on Re h .
Streamwise evolutions of momentum thickness θ m(x) for various Re h .
The Re h -dependence of the shear-layer growth rate (K θ) and mixing length (l m) based on Prandtl's mixing length hypothesis where l m is proportional to K y as embodied in Eq. (13) .
Streamwise evolutions of the integral length scale, Λ (x) /h for various cases of Re h . The asymptotic decrease of K Λ with increasing Re h is shown in the inset.
Streamwise evolution of the one-dimensional turbulent kinetic energy E k normalized by U 2 c(x) together with the data of Namar and Otugen. 12
Lateral profiles of turbulence intensity u n = <[u(x, y)]>1/2/U c(x) measured across the jet for Re h = (a) 1500, (b) 3000, (c) 7000, (d) 10 000, and (e) 16 500.
Dependence of streamwise turbulence intensity on Re θ(x) for Re h = 3000–16 500.
Streamwise evolutions of the local turbulent Reynolds number . Note: <u 2 p(x) > 1/2 ≡ peak value of shear layer turbulence intensity y 0.5 (x) ≡ jet half-width and <u 2 p(x) > 1/2 is deduced from Fig. 10 .
Streamwise evolutions of the peak shear-layer turbulence intensity, <u 2 p(x) > 1/2/U c(x) in %. Symbols are identical to Fig. 12 .
Lateral profiles of (a) the skewness factors (Su) and (b) the flatness factors (F u) of the fluctuating velocity measured across the jet at x/h = 20. The dashed (- - -) line shows the maximum skewness in the outer boundary layer.
Streamwise evolutions of the Kolmogorov microscales (η/h) as per Deo et al. 17
Streamwise evolutions of the Taylor microscales (λ/h).
Centerline variation of the local Taylor microscale-based Reynolds number, λ(x)/υ. The plane jet data of Mi et al. 42 is included.
The streamwise evolutions of the ratio of sampling frequency, f cut-off against (a) Kolmogorov frequency, f k = U c (x)/ [2π η (x)], (b) Eddy turnover Taylor frequency, f inertial. Note: dashed line in (a) shows over-filtering for higher Re h cases.
The Re h -dependence of (a) Kolmogorov scales (η), (b) Taylor microscales (λ) in the self-preserving field measured between x/h = 50 and 160.
The lateral distributions of (a) Kolmogorov scales (η), (b) Taylor microscales (λ) measured at x/h = 20.
The lateral distributions of (a) the dissipation of turbulent kinetic energy (ɛh/U 3 b), (b) Kolmogorov frequency, f k (x, y) = U(x, y)/2πη at x/h = 20. The sampling frequency (f c) is shown with the dashed line.
Streamwise evolutions of turbulent kinetic energy spectra, on Re h between x/h = 0 and 10. The dashed lines show energy production zones and nth spectra have been transformed in coordinate-axis by a factor of 10n.
Streamwise evolutions of compensated spectra of the turbulent kinetic energy, on Re h and Re y0.5 measured between x/h = 20 and 160. The width of the inertial sub-range where ∼ k −5/3 for is characterized by the flat region on the ordinate axis.
The probability density functions PDF of centerline velocity fluctuations u c(x). The Gaussian distribution PDF is shown.
(a) Lateral distribution of the intermittency factor, γ estimated indirectly from the flatness factor of the fluctuating velocity at x/h = 20 compared with Gutmark and Wygnanski's 47 direct measurements. (b) Autocorrelation functions, R uu on the jet centerline for Re h = 1500 and 16 500.
Comparing the probability density function (PDF) of the fluctuating velocity (u) at x/h = 20 between the jet centerline (blue dash line) and edge (red full line). The y axis is normalised by p(u n) at u n = 0 and Gaussian PDF is .
The Re h -dependence of turbulent viscosity (υT) and turbulent Reynolds number (Re T = U b h /υ T).
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