Numerical Study on Supersonic Co-flowing Jet with Varying Lip …
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Wake region appears but its dominance is less felt. Surrounding and central jets
merge at a near exit region. The outer jet shields inner jet to elongate supersonic
core as shown in Fig. 4a. Because of the shock crossover, subsonic pockets appear
and due to expansion wave crossover, supersonic pockets appear as observed from
Fig. 4b. Shear layer found dominant between jets and found less dominant between
outer jet and ambient atmosphere (Fig. 4c). Shock crossover appears in the numerical
shadowgraph (density gradient, Fig. 4d).
Comparing to CFJ with LT 2 mm, LT 7.75 mm has dominant wake region (Fig. 5a).
The wake region is clearly visible between jets, with a least value of 0.4 bar, i.e.,
subatmospheric region. Due to the wake region, the secondary jet merges with the
primary jet at an axial distance, and this happens because of mixing core length
that has been shortened. We can see here that the pressure is dropping because of
reverse shock crossover. Because of this, recirculation zone appears in Mach number
Fig. 4 Contours of LT 2 mm for NPR 3: a total pressure, b Mach number, c turbulent kinetic
energy, and d density gradient
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Wake region appears but its dominance is less felt. Surrounding and central jets
merge at a near exit region. The outer jet shields inner jet to elongate supersonic
core as shown in Fig. 4a. Because of the shock crossover, subsonic pockets appear
and due to expansion wave crossover, supersonic pockets appear as observed from
Fig. 4b. Shear layer found dominant between jets and found less dominant between
outer jet and ambient atmosphere (Fig. 4c). Shock crossover appears in the numerical
shadowgraph (density gradient, Fig. 4d).
Comparing to CFJ with LT 2 mm, LT 7.75 mm has dominant wake region (Fig. 5a).
The wake region is clearly visible between jets, with a least value of 0.4 bar, i.e.,
subatmospheric region. Due to the wake region, the secondary jet merges with the
primary jet at an axial distance, and this happens because of mixing core length
that has been shortened. We can see here that the pressure is dropping because of
reverse shock crossover. Because of this, recirculation zone appears in Mach number
Fig. 4 Contours of LT 2 mm for NPR 3: a total pressure, b Mach number, c turbulent kinetic
energy, and d density gradient