scholarly journals Study on Cleaning Effect of Different Water Flows on the Pulsed Cavitating Jet Nozzle

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Chengting Liu ◽  
Gang Liu ◽  
Zuoxiu Yan
Keyword(s):  
Flow Rate ◽  
Velocity Fluctuation ◽  
Pulse Frequency ◽  
Erosion Effect ◽  
Fluctuation Amplitude ◽  
Jet Nozzle ◽  
Cleaning Methods ◽  
Outside Diameter ◽  
Cavitating Jet ◽  
Peak Value

The method of cleaning by self-excited pulsed cavitating jet was proposed according to cleaning characteristics and requirements of large storage equipment. This method has many advantages compared with other cleaning methods. In order to achieve the optimum cleaning effects, experimental research on working status of the nozzle at different flow rates was conducted and analysis was carried out from the following four aspects: cavitation morphology, pressure pulse frequency, velocity fluctuation amplitude, and erosion effect. The research results showed that flushing effects in the nozzle without cavitation were far below those with cavitation; when the flow rate increased to over 2.7 m3/h, cavitation began to appear in the chamber. When Q = 7.2 m3/h, the velocity fluctuation amplitude was about 17.25 m and pressure fluctuation occurred for 86 times (maximum) within 1 s. During the experiment on erosion effects, the flow rate had little influence on outside diameter of the erosion circle. The erosion rate increased with the increase of the flow rate, reached the peak value at Q = 7.2 m3/h, but slightly decreased subsequently.

scholarly journals A Review on the Erosion Mechanism in Cavitating Jets and Their Industrial Applications

2021 ◽  
Vol 11 (7) ◽  
pp. 3166
Author(s):  
Mouhammad El Hassan ◽  
Nikolay Bukharin ◽  
Wael Al-Kouz ◽  
Jing-Wei Zhang ◽  
Wei-Feng Li
Keyword(s):  
Industrial Applications ◽  
Operating Conditions ◽  
Extensive Literature ◽  
Well Drilling ◽  
Erosion Mechanism ◽  
Comprehensive Literature Review ◽  
Erosion Effect ◽  
Jet Nozzle ◽  
Cavitating Jets ◽  
Cavitating Jet

Cavitating jets have been widely studied for over a century, but despite the extensive literature on this subject, the implementation of cavitating jets in many industries is still very limited due to technical challenges. The main purpose of the present paper is to provide recommendations on using the cavitating jets based on a comprehensive literature review on the erosion mechanism in these jets. Self-resonating jets are extensively discussed in the present paper due to their importance in amplifying the erosion effect of cavitating jets. The influence of different jet nozzle geometric parameters and the operating conditions of the cavitating jet flow on the erosion mechanism is also discussed. Finally, well drilling in addition to multiple other industrial applications of cavitating jets are examined.

Erosion Experiment of Self-Excited Oscillation Pulsed Jet

2014 ◽  
Vol 937 ◽  
pp. 614-619
Author(s):  
Chuan Lin Tang ◽  
Jie Pei ◽  
Dong Hu ◽  
Xiao Ting He
Keyword(s):  
Significant Influence ◽  
Cavity Length ◽  
Experimental Studies ◽  
The Self ◽  
Erosion Depth ◽  
Pulsed Jet ◽  
Excited Oscillation ◽  
Erosion Effect ◽  
Erosion Volume ◽  
Peak Value

In order to improve the erosion effect of jet under submergence condition, experimental studies of erosion generated from the self-excited pulsed jet was carried out by using developed self-excited oscillation nozzle. The erosion volume and depth of pulsed jet were measured and taking mortar block as an erosion part. The results were that the standoff has significant influence on erosion effect. The erosion volume firstly decreases with increases in cavity length and then increases to a peak value. Erosion volume of pulsed jet is significantly higher than that of continuous jet, the erosion depth of two jet has slight difference.

Degradation of Organophosphorus Pesticide in a Packed-Bed Plasma Reactor: Effects of Operating Parameters and Kinetics Study

2013 ◽  
Vol 781-784 ◽  
pp. 1637-1645 ◽  
Author(s):  
Ting Jun Ma ◽  
Yi Qing Xu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Plasma Reactor ◽  
Organophosphorus Pesticide ◽  
Packed Bed ◽  
Pulse Frequency ◽  
Gas Flow Rate ◽  
Peak Voltage ◽  
Initial Concentration

The degradation effectiveness and reaction kinetics of representative organophosphorus (OP) pesticide in a packed-bed plasma reactor have been studied. Important parameters, including peak voltage, pulse frequency, gas-flow rate, initial concentration, diameter of catalyst particles, and thickness of catalyst bed which influences the removal efficiency, were investigated. Experimental results indicated that rogor removal efficiency as high as 80% can be achieved at 35 kV with the gas flow rate of 800 mL/min and initial concentration of 11.2 mg/m3.The removal efficiency increased with the increase of pulsed high voltage, and pulse frequency, the decrease of the diameter of catalyst particles and the thickness of catalyst bed. Finally, a model was established to predict the degradation of the rogor, which generally can simulate the experimental measurements to some degree.

Secretion of K and fluid by rat submaxillary during sympathetic nerve stimulation

1975 ◽  
Vol 229 (4) ◽  
pp. 1056-1061 ◽  
Author(s):  
LH Schneyer
Keyword(s):  
Steady Flow ◽  
Flow Rate ◽  
Sympathetic Innervation ◽  
Stimulus Frequency ◽  
Submaxillary Gland ◽  
Pulse Frequency ◽  
Initial Flow ◽  
Saliva Secretion ◽  
High Concentrations ◽  
Two Phases

Stimulation of the sympathetic innervation to rat submaxillary gland is known to evoke saliva which contains high concentrations of potassium (130-160 meq/liter). Relationships were examined between salivary [K] and several parameters of the stimulation, including pulse frequency and duration of the stimulus train and rate of flow of the evoked saliva. Secretion of sympathetically evoked saliva was found to occur in two phases. After stimulation was started, flow rate was relatively high initially, and then decreased to a lower, relatively steady value. Initial and steady flow rates were maximal when stimulus frequency was 10 Hz. Salivary [K] was lowest initially, and, at that time, was inversely related to flow rate. At steady flow, [K] was flow independent. While salivary [K] was lower during initial than during steady secretion, the rate of K secretion was initially higher. During the initial phase, K decreased in the gland, and this decrease was sufficient to account for the increased amount of K secreted in initial saliva and for the increased initial flow.

Development and Analysis of Robust Anti-Wear Design of a-C:Zr Films by Taguchi Methods

2011 ◽  
Vol 189-193 ◽  
pp. 3647-3652
Author(s):  
Wesley Huang ◽  
Ching Jyi Chen ◽  
Ming Der Jean
Keyword(s):  
Friction Coefficient ◽  
Bias Voltage ◽  
Flow Rate ◽  
High Hardness ◽  
Pulse Frequency ◽  
Taguchi Methods ◽  
Control Factors ◽  
Methane Flow Rate ◽  
Percent Contribution ◽  
Methane Flow

Amorphous carbon (a:C-H) coatings with high hardness and low friction coefficient are widely applied in die and mold industries. Zirconium-containing a:C-H (a-C:Zr) coatings with double interlayered Zr/ZrC were deposited by unbalanced magnetron sputtering system. A L18 orthogonal array experiment was designed to investigate the effect of process parameter on the friction coefficient of deposited films. Control factors, such as methane flow rate, bias voltage, sputtering frequency, zirconium target current and work distance were schematized for experiments. The experimental results show that zirconium target current exhibits about 45% percent contribution in analysis of variance, and the friction coefficient of a-C:Zr coatings range from 0.13 to 0.31. From effect plots, the optimum parameters are bias voltage at -70V, zirconium target current at 0.6 A, pulse frequency at 90 kHz, methane flow rate at 6 sccm and work distance at 15 cm. The friction coefficient performs as 0.106 in verification experiments. Meanwhile, one-by-one factorial experiments were also carried out and discussed in this study.

scholarly journals Features of creation and use of effective heat exchangers

2020 ◽  
Vol 216 ◽  
pp. 01124
Author(s):  
Shavkat Agzamov ◽  
Sevinar Nematova
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Prandtl Number ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Heat Transfer Equation ◽  
The Heat Transfer Coefficient ◽  
Outside Diameter

The article discusses the features of the creation and use of efficient heat exchanger. Designs of pipes with a developed heat exchange is presented. The procedure for determining the degree of development of the heat exchanging surface, the heat transfer coefficient, and the calculation of the heat transfer equation are given. As a result of creating efficient heat exchangers, three main parameters are used: the pipe outside diameter; the estimated flow rate; the Prandtl number.

Optimisation of air-jet vortex generators with respect to system design parameters

1999 ◽  
Vol 103 (1028) ◽  
pp. 475-480 ◽  
Author(s):  
T. P. Bray ◽  
K. P. Garry
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vortex Generator ◽  
Design Parameters ◽  
Air Jet ◽  
System Input ◽  
System Requirements ◽  
Jet Nozzle ◽  
Definition Of

Abstract A simple technique is proposed that allows the definition of the geometry and characteristics of an air-jet vortex generator to be defined, using the system requirements in practical design. Typically, the aircraft designer is concerned with the mass flow-rate and air pressure requirements of any pneumatic system for inclusion to an airframe. These parameters are not congruent with those for air-jet vortex generator aerodynamic design, and therefore, some tool is required to bridge the gap. Such a tool is proposed, based on empirical methods for the prediction of air-jet vortex generator behaviour. The technique allows the comparison of the vortex strength, and the system inputs (the jet mass flow-rate and the air-jet plenum pressure) for the air-jet, for a range of jet nozzle diameters and jet velocity ratios. Through this comparison, the optimum air-jet design can be reached for a given system input.

Gas Metal Arc Welded (GMAW) Joint Strength Comparison of Aluminum Sheet (5754) and Exturded (6063) Alloys

2007 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Armando Joaquin ◽  
Matthew Zaluzec ◽  
Chris Karas
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Gma Welding ◽  
Surface Condition ◽  
Power Input ◽  
Pulse Frequency ◽  
Weld Penetration ◽  
Phase 2 ◽  
Lap Joint ◽  
Gas Flow Rate

The development of lightweight vehicles, in particular aluminum intensive vehicles, require significant manufacturing process development for joining and assembling aluminum structures. Currently, 5xxx and 6xxx aluminum alloys are being used in various structural applications in a number of lightweight vehicles worldwide. Various joining methods, such as GMAW (it is also referred as Metal Inert Gas Welding), Laser and adhesive bonding have been investigated as technology enablers for high volume joining of 5xxx, and 6xxx series alloys. In this study, GMA welding was used to join 5754 non-heat-treatable alloy sheet and 6063-T6 heat treatable extrusion products. The objective of this study was to develop optimum weld process parameters for non-heat-treatable 5754 aluminum and heat treatble 6063-T6 alloys. For both the alloys, the lap joint configuration was used. The GMA welding equipment used in this study was an OTC/Daihen CPD-350 welding systems and DR-4000 pulse power supply. In the first phase of the experiments for 5754 aluminum alloy, the factors selected for the experiment were power input (torch speed, voltage, current, wire feed), pulse frequency, gas flow rate and surface condition. A full factorial design of experiment (DOE) was conducted (DOE #1) to understand the main and interaction effects on lap joint failure and weld penetration. Based on the results from phase 1 results, surface condition was eliminated in the phase 2 experiments. In phase 2 experiments for heat treatable alloys 6063 T6, the factors selected were power input (torch speed, voltage, current, wire feed), pulse frequency, gas flow rate, torch angle, and arc intensity. A partial factorial DOE was conducted (DOE # 2) primarily to understand the main effects and some two level interaction effects. For both phase 1 (non-heat treatable alloy 5754) and phase 2 (heat treatable alloy 6063-T6) experiments, the factors influence on the mechanical properties of the lap joint, metallurgy (weld penetration) and micro hardness were evaluated. Post weld analysis indicates for non heat treatable alloy 5754, power input and gas flow rate are the two signficant factors (statistically) based on lap shear load to failure and weld penentration data. For heat treatable alloy 6063, power input was the significant factor on joint load to failure, however, for weld penetration, power input, pulse frequency and gas flow rate were the significant factors. Based on the joint strength and weld penetration, optimum weld process factors were determined for both non-heat treatable alloy 5754 and heat treatble alloy 6063 T6.

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