Numerical study of amplitude and frequency effects upon a pulsating jet

Marzouk, Salwa; Aïssia, Habib Ben; Palec, Georges Le

doi:10.1016/j.compfluid.2015.09.008

Cited by 5 publications

(2 citation statements)

References 17 publications

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“…The research results showed that the destruction results of acoustic-wave-excited pulsed water jets were far superior to conventional continuous water jets. Akash Nag et al [10] showed that acoustic-waveexcited pulsed water jets had better dynamic impact effects on tantalum, mainly relying on the periodic impact of water clusters; Saloua Marzouk et al [11] showed that pulsating jets generate significant pressure oscillations. Compared to the insufficient utilization of jet energy in the disc truncation equal pulse water jet generation method [12,13], in order to further fully utilize the water hammer impact generated by the initial pulse of the jet on the rock, Lu et al [14,15] proposed a new type of pressurized pulse water jet technology, which uses low-pressure fluid to drive the plunger reciprocating impact finite cavity to preinject fluid and periodically sprays high-speed pulse water jet.…”

Section: Introductionmentioning

confidence: 99%

Influence of Hydraulic Parameters on Multi-Stage Pulse Characteristics of Pressurized Pulsed Water Jet

Zhang,

2023

Processes

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The multi-stage pulse competition of pressurized pulsed water jet becomes the initial pulse at the head tip, and hydraulic parameters are the key parameters that affect the characteristics of multiple pulses. Based on the ultra-high-speed imaging system, a pressurized pulsed water jet flow field capture system was constructed, and the effects of initial pressure and driving pressure of the pressurized chamber on the characteristics of multi-stage pulses were studied. The experimental results show that as the initial pressure of the booster chamber increases, the jet changes from a discontinuous state to a continuous state, and the multi-level pulse simultaneously changes from dominant multi-pulse to implicit multi-pulse; as the driving pressure increases, the initial spacing between the first pulse and the second pulse increases, and the peak velocity of the initial pulse gradually increases. At the same time, the location of the peak velocity also shifts away from the nozzle as the driving pressure increases. In addition, the peak velocity of the initial pulse is relatively close to the theoretical velocity of the continuous jet under driving pressure conditions.

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Section: Introductionmentioning

confidence: 99%

Influence of Hydraulic Parameters on Multi-Stage Pulse Characteristics of Pressurized Pulsed Water Jet

Zhang,

2023

Processes

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“…They showed that jets pulsed with a high pulsing amplitude entrained surrounding fluid more quickly than steady jets. Marzouk et al (2015) studied numerically by modeling with large Reynolds numbers the influence of an initial perturbation on the spatial and temporal evolutions of the dynamic and thermal quantities of a plane jet in turbulent regime. These authors found that the pulsation considerably affects the flow in a region close to the nozzle and then reach an asymptotic regime identical to that of a non-pulsed jet.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of an Acoustically Excited Plane Jet at Low Reynolds Numbers

Marzouk¹,

Hnaien²

2019

JAFM

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The dynamics of a vertical two-dimensional air jet under acoustic excitations at a low Reynolds number are investigated experimentally. The perturbation is introduced by means of a loudspeaker located in a settling chamber before the nozzle exit. The experiments are operated at Strouhal number St ranging from 0 to 1 and for different pulsation amplitudes. A laser plan is used to visualize the flow and the hot-wire anemometry for more specific measures of the mean and fluctuation velocity. The discussion is focused on the influence of two parameters governing the flow: the Strouhal number St and pulsing amplitude. The main results show that the flow consisting of the vortex propagating downstream a nozzle exit is strongly affected by the excitation. Indeed, the introduction of an external perturbation introduces a more rapid degeneration of the potential core with the appearance of vortices near the nozzle as the pulsation amplitude increases. These vortices are amplified and become larger than the nozzle width which induces the enhancing of the entrainment and mixing effects of the shear layers. Another very important phenomenon is observed: the excitation has led to the formation of a switching from the asymmetric mode (sinuous mode) to the symmetric mode (varicose mode).

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