Influence of nozzle geometry on the near-field structure of a highly underexpanded sonic jet

Flow characteristic of highly underexpanded jets from various nozzle geometries

“…After that, there have been some efforts [23][24][25][26][27][28] devoted to directly comparing the flow properties between the underexpanded jets issuing from different nozzle geometries. For example, Otobe et al [23] studied the influences of the nozzle geometry on the Mach disk height and diameter in highly underexpanded jets by solving the two-dimensional, axisymmetric Euler equations. Zare-Behtash et al [24,25] explored the effect of nozzle geometry on the initial shock and vortex development in supersonic underexpanded jets using high-speed schlieren photography and PIV measurements.…”

“…Zhang et al [28] investigated the initial flow differences between the supersonic underexpanded circular and square jets based on large eddy simulation. Note that most of these studies focused on the differences of near-field shock structures [23,26] or the initial flow development [24,25,28] between the jets. In the case of obtaining an indepth and comprehensive understanding on the noncircular jets, a detailed comparisons of their various flow characteristics are thus necessary.…”

The effect of inflow conditions on the development of non-swirling versus swirling impinging turbulent jets

“…In addition, very little work has been conducted into the fundamental development of turbulent jets as they transition from free to impinging, and thereafter from non-swirling to swirling (for the same inflow, impingement conditions and nozzle geometry). With the effects of upstream inflow conditions potentially affecting even free jet development [50,[78][79][80], there is merit in the current study which looks for the same nozzle geometry at impinging swirl jet transitions and inflow conditions. Of the few comparative experimental studies undertaken between free and impinging (non-swirling) jets, those in axisymmetric configurations by Donaldson and co-workers [81,82], Popiel and Trass [83] and Looney and Walsh [84] are, however, derived at varied conditions, which makes it difficult to draw summative observations on the fundamental effects of jet impingement, and swirl, on jet development.…”

Numerical Investigation of the Air Flow Effects on Amorphous Alloy Ribbon Formation

“…The air flow over the roller played a key role, like the turbulence flow around a two-dimensional hump [10] and to fluctuated cool the alloy liquid. The nozzle effect and geometry are also the important factors [11]- [12]. In this paper, numerical simulation of air flow around the contact zone was carried out, including the air flow field over the rotating roller, the flow air scouring the contact zone, and the air flow around the nozzle.…”