Study on velocity and pressure characteristics of self-excited oscillating nozzle

Zhang, Xiaojun; Li, Xiaqing; Nie, Songlin; Wang, Liping; Dong, Jianghui

doi:10.1007/s40430-020-02717-4

Cited by 12 publications

(4 citation statements)

References 35 publications

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“…erewith, the generation, growth, motion, and collapse of these large-scale vortices will lead to a strong pulsating pressure acting on the jet periodically. Coupled with the jet instability and interactions of the jet and the environmental fluid, the selfexcited oscillation jet will be formed, and the oscillation phenomenon will form a closed loop in the oscillation cavity [34][35][36].…”

Section: Acoustic Mechanismmentioning

confidence: 99%

Numerical Study on Flow-Induced Noise of Deflector Jet Servo Valve Based on LES/Lighthill Hybrid Method

Ren

Yan

Cai³

2022

Shock and Vibration

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The flow-induced noise occurring in the prestage of the deflector jet servo valve (DJV) significantly affects the performance of DJV, which is a critical issue for electrohydraulic servo valves. To capture the root causes of flow-induced noise, DJV is numerically studied using computational aeroacoustics (CAA) methods in this paper. The acoustic field is investigated with Lighthill’s acoustic analogy based on the pulsation data from a large eddy simulation (LES). The flow-induced noise generation mechanism in DJV is revealed by analyzing the sound pressure level and vorticity distribution at different moments. Moreover, a kind of oscillation cavity model based on the Helmholtz oscillator is built, which reveals that the flow-induced noise is caused by self-excited oscillation and vortex. In addition, the result shows that continuous broadband dipole noise with medium- and high-frequency components of 1100 Hz and 2501 Hz dominates the DJV flow field. In order to avoid unexpected resonance, the natural frequency of the prestage should not coincide with the frequency of the flow oscillation frequency. Thus, this work can benefit the design and optimization of the prestage structure.

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Section: Acoustic Mechanismmentioning

confidence: 99%

Numerical Study on Flow-Induced Noise of Deflector Jet Servo Valve Based on LES/Lighthill Hybrid Method

Ren

Yan

Cai³

2022

Shock and Vibration

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“…Hydrodynamic cavitation can be produced by changes in flow and pressure and its generation is usually based on a specific structure. The self-oscillating pulse jets formed by the self-oscillating nozzle [7,8] have a strong cavitation effect in this type of structure [9]. The research on self-oscillating jet nozzles has an important academic and market value.…”

Section: Introductionmentioning

confidence: 99%

Multi-Objective Parameter Optimized Design of Self-Oscillating Cavitation Jet Nozzles

Wang,

Li,

Song

et al. 2023

Energies

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Self-oscillating cavitation jet technology has become a research hotspot of scholars in various fields. However, existing research lacks a summary of the rules of the influence of various factors on the cavitation performance, such that efficient and stable extensive engineering applications are impossible to achieve. This paper aims at optimizing the design of the self-oscillating cavitation jet nozzle (SOCJN) as the objective; this is carried out by the experimental design, optimal Latin hypercube method, and response surface method in (design of experiment) DOE methods on the basis of the ISIGHT optimization method. In addition, taking the vapor volume fraction and cavitation number as a research objective, the obtained optimal structural parameters of the nozzles are applied under the condition of clear water to establish the function mapping relationship between the external geometric characteristics and the vapor volume fraction and cavitation number; then, this is compared with the experiment. The results indicate that the second-order response surface approximate model is suitable for the SOCJN and there is an error smaller than 8% between the approximate model results and the calculated results of the nozzle response. When the diameter of the upper nozzle is D1 = 4.7 mm, the ratio of the upper nozzle’s diameter to the lower’s diameter (D1/D2) is 2.6 and the ratio of the chamber length to the chamber diameter (L/D) is 0.63; pulse jets from the SOCJN have the best pitting effect on the sample at the monitoring point when the convergence angle of collision wall α is 120°. When the structural parameters of the nozzle are optimal structural parameters, the cavitation performance is the best at the initial pressure of 4.8 MPa. This research provides a reference for the optimized design of the SOCJN for industrial applications.

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“…Studies have discovered that area discontinuity at the nozzle inlet enhances peak pressure 26 . Recently, some scholars used FLUENT (Ansys Academic Research Mechanical, Fluent 18.0) software to study the speed and pressure characteristics of the nozzle in a low‐pressure state and analyzed important factors affecting the pulse jet 33 …”

Section: Introductionmentioning

confidence: 99%

“…26 Recently, some scholars used FLUENT (Ansys Academic Research Mechanical, Fluent 18.0) software to study the speed and pressure characteristics of the nozzle in a low-pressure state and analyzed important factors affecting the pulse jet. 33 It is worth noting that the Chinese scholar Li Xiaohong introduced the fluid vibration characteristics of the water jet transmission system through the transfer matrix method in the book "Water Jet Theory and Its Application in Mining Engineering." In summary, when scholars study the influence of the water jet transmission system on output characteristics, they are more concerned with the mechanism of a certain device.…”

Section: Introductionmentioning

confidence: 99%

Effects of pulsating fluid at nozzle inlet on the output characteristics of common and self‐excited oscillation nozzle

Feng

Wang

Kong

2022

Energy Science & Engineering

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High-speed water jets are key technologies for increased production efficiency in oil drilling, and high-speed self-excited oscillating pulsed water jets (SEOPWs) offer many advantages compared to continuous jets for most industrial applications. Therefore, many studies have focused on this topic.However, the current studies on hydraulic pulsed jets have rarely extended to integrated modeling of the high-speed water jet transmission process. To better apply the SEOPWs, based on fluid mechanics, the theoretical model of the plunger pump-pipeline-nozzle is established, and the sensitivity of different nozzles on the pulsating fluid is studied in the time domain.Furthermore, the vibration characteristics of the nozzle are further investigated in the frequency domain. The results show that the common nozzle has an enlarged role in the pressure amplitude, the Helmholtz nozzle enlarges the pressure peak and amplitude, and the amplification is more obvious with the speedy growth on the plunger pump. However, as the pipeline becomes longer, the difference between the pressure of the inlet and outlet does not change. Therefore, the nozzle is more sensitive to the change in the plunger pump speed. In the frequency domain, the secondary frequency peak for the Helmholtz nozzle is 1.26 times larger than the interference frequency, while it is 1.08 times for the common nozzle. Helmholtz nozzles tend to produce stronger natural vibrations than common nozzles. By comparing the impact force, the experimental results show good agreement with the simulated results. The study provides a theoretical basis for water jet-assisted drilling in deep wells and lays the foundation for the better application of self-oscillating impact drilling tools.

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Study on velocity and pressure characteristics of self-excited oscillating nozzle

Cited by 12 publications

References 35 publications

Numerical Study on Flow-Induced Noise of Deflector Jet Servo Valve Based on LES/Lighthill Hybrid Method

Numerical Study on Flow-Induced Noise of Deflector Jet Servo Valve Based on LES/Lighthill Hybrid Method

Multi-Objective Parameter Optimized Design of Self-Oscillating Cavitation Jet Nozzles

Effects of pulsating fluid at nozzle inlet on the output characteristics of common and self‐excited oscillation nozzle

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