Design and analysis of a synthetic jet actuator-based fluid atomization device

2017 ◽  
Vol 28 (17) ◽  
pp. 2307-2316 ◽  
Author(s):  
Paul Gilmore ◽  
Vishnu-Baba Sundaresan ◽  
Jeremy Seidt ◽  
Jarrod Smith
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
Fluid Management ◽  
Synthetic Jet ◽  
System Level ◽  
Substrate Thickness ◽  
High Speed Imaging ◽  
Peak Displacement ◽  
Synthetic Jet Actuator

High-pressure nozzles and ultrasonic atomizers are the two most common devices used to generate sprays. Each of these has some disadvantages, such as controllability in high-pressure nozzles and fluid management challenges in ultrasonic devices. To overcome these limitations, a new atomization technology using a synthetic jet actuator was developed and is presented here. The work includes design and experimental analysis of both the stand-alone synthetic jet actuator and the synthetic jet-based atomization device. The synthetic jet actuator is designed using a model-based approach and characterized by measuring dynamic orifice pressure, diaphragm peak-to-peak displacement, flow rate, and power consumption. Orifice pressure reaches 296 Pa at a flow rate of 16 mL/s and 186 Pa at a flow rate of 37 mL/s for two possible synthetic jet actuator geometries, respectively. Piezoelectric diaphragm displacement reaches 50 µm with a brass substrate thickness of 0.20 mm. The synthetic jet-based atomization device is characterized with high-speed imaging and measurement of water atomization rate. It produces droplets with average sizes of 92–116 µm at maximum rates of 19–28 µL/s, depending on the geometry of the synthetic jet actuator. The outcomes of this work are principles for designing effective synthetic jet-based atomization devices, as well as system-level implementation concepts and control schemes.

Analysis of Static Characteristics of Pressure Seal in Actual High Pressure Pump

2011 ◽  
Author(s):  
Isao Hagiya ◽  
Katsutoshi Kobayashi ◽  
Yoshimasa Chiba ◽  
Tetsuya Yoshida ◽  
Akira Arai
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
Control Volume ◽  
Leakage Flow ◽  
High Pressure Pump ◽  
Flow Rates ◽  
Leakage Flow Rate ◽  
Rotor Dynamic ◽  
Pressure Seal

We predicted the leakage flow rates of a pressure seal in an actual high-pressure multistage pump. Since the pressure of the actual pump is higher than that of a model pump, accurate prediction of leakage flow rate and rotor dynamic forces for an actual pump is more difficult than that for a model pump. A non-contacting seal is used as a pressure seal to suppress leakage flow for high-pressure multistage pumps. When such pumps are operated at high speed, the fluid force acting on an eccentric rotor may cause vibration instability. For vibration stability analysis, we need to estimate static and dynamic characteristics of the pressure seals, i.e., leakage flow rate and rotor dynamic coefficients. We calculated the characteristics of the pressure seal based on Iwatsubo group’s method. The pressure seal we developed has labyrinth geometry consisting of grooves with different sizes. This method numerically calculates the characteristics of the grooved seal by using a three-control-volume model and a perturbation method. We compared the calculated and measured leakage flow rates. We found that the calculated results quantitatively agreed with the measured one in the actual pump and the characteristics of pressure and velocity for the seal with non-uniform-sized grooves were clarified.

Characterisation of Waves and Ligaments in Films Close to an Aeroengine Ball Bearing

2019 ◽  
Author(s):  
Jee Loong Hee ◽  
Kathy Simmons ◽  
David Hann ◽  
Michael Walsh
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Ball Bearing ◽  
Capillary Waves ◽  
Operating Conditions ◽  
Research Centre ◽  
Shaft Speed ◽  
High Speed Imaging ◽  
Liquid Phases ◽  
Mass Transfers

Abstract Surface waves are observed in many situations including natural and engineering applications. Experiments conducted at the Gas Turbine and Transmissions Research Centre (G2TRC) used high speed imaging to observe multiscale wave structures close to an aeroengine ball bearing in a test rig. The dynamic behavior and scale of the waves indicate that these are shear-driven although highly influenced by gravity at low shaft speed. To understand the interactions between gas and liquid phases including momentum and mass transfers, characterization of the observed waves and ligaments was undertaken. Waves were studied at surfaces close to the ball bearing and ligaments were assessed near the cage. Characterization was in terms of frequency and wavelength as functions of speed, flow-rate, bearing axial load and gravity. The assessments confirmed the existence of gravity-capillary waves and capillary waves. Gravity-capillary waves were measured to have a longer mean wavelength on the co-current side of the bearing (gravity and shear acting together) compared to the counter-current side (gravity and shear opposing). Using a published definition of critical wavelength (λcrit), measured wavelengths at 3,000 rpm were 2.56λcrit on the co-current side compared to 1.86λcrit at the countercurrent location. As shaft speed increases, wavelength reduces with transition to capillary waves occurring at around 0.83λcrit. At shaft speeds beyond 5000 rpm, capillary waves were fully visible and the wavelength was obtained as 0.435λcrit. Flow-rate and load did not significantly influence wavelength. Wave frequency was found to be proportional to shaft speed. The gravity-capillary waves had frequencies within the range 13–25 Hz while capillary waves exhibited a frequency well beyond 100 Hz. The frequencies are highly fluctuating with no effect of load and flow rate observed. Ligaments were characterized using Weber number and Stability number. The number of ligaments increased with shaft speed. A correlation for ligament number based on operating conditions is proposed.

High-Speed Imaging Study on the Effects of Internal Geometry on High-Pressure Gasoline Sprays

2020 ◽  
Author(s):  
Mario Medina ◽  
Yichen Zhou ◽  
Mohammad Fatouraie ◽  
Margaret Wooldridge
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Imaging Study ◽  
High Speed Imaging ◽  
Internal Geometry

Achieving a High-Speed and Momentum Synthetic Jet Actuator

2016 ◽  
Vol 29 (2) ◽  
pp. 04015040 ◽  
Author(s):  
Tyler Van Buren ◽  
Edward Whalen ◽  
Michael Amitay
Keyword(s):  
High Speed ◽  
Synthetic Jet ◽  
Synthetic Jet Actuator

Experimental and Analytical Leakage Characterization of Annular Gas Seals: Honeycomb, Labyrinth and Pocket Damper Seals

2011 ◽  
Author(s):  
Nuo Sheng ◽  
Eric J. Ruggiero ◽  
Ravindra Devi ◽  
Jianping Guo ◽  
Massimiliano Cirri
Keyword(s):  
New York ◽  
High Pressure ◽  
High Speed ◽  
System Level ◽  
Operating Pressure ◽  
Test Rig ◽  
Flow Mechanisms ◽  
Successful Design ◽  
Gas Seals ◽  
Analytical Tools

Modern day turbomachinery requires the use of annular gas seals to provide flow restriction from high pressure to low pressure regions within the machine. These flow restrictions are critical design points in the overall performance of the machine and directly impact the system-level efficiency. Consequently, understanding the leakage performance of a given seal element as a function of operating pressure, rotor speed, and rotor offset is critical to the successful design of the turbomachine. In the present work, three annular gas seals are experimentally tested on a leakage test rig at GE Global Research (Niskayuna, New York). The test rig is capable of high-speed, high-pressure flow testing and has a radial degree of freedom that enables non-concentric leakage characterization. The leakage performances of a labyrinth, honeycomb and pocket damper seals are compared over a range of inlet pressures and pressure ratios. Analytical tools, including a CFD model and a Bulk Flow Code, are developed to provide leakage prediction and to establish understanding of underlying flow mechanisms. Predictions of the seal leakage are found to be in good agreement with experimental data.

scholarly journals Development of High-Efficiency, High-Speed and High-Pressure Ambient Temperature Filling System Using Pulse Volume Measurement

2019 ◽  
Vol 9 (12) ◽  
pp. 2491
Author(s):  
SeBu Oh ◽  
SeHoon Oh ◽  
ByeongRo Min
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
High Efficiency ◽  
Response Speed ◽  
Volume Measurement ◽  
Economic Feasibility ◽  
Industrial Sectors ◽  
Filling System ◽  
Filling Time

Adjusting the filling pressure is essential to fit the final gas volume when charging a carbonated beverage with high pressure. However, in the previous mechanical carbonated ambient filling system, it was difficult to control and monitor the charging conditions such as pressure, temperature and flow rate. In this study, we have developed a high efficiency carbonated ambient filling system capable of high speed and high pressure filling, by using a pulse type electronic flow-meter. The response speed characteristics of the M(BC) and F(MH) series valves were investigated. LMS Imagine.Lab Amesim (Siemens PLM Software) was used to calculate the charging and discharging time of the system under a high CO2 gas pressure condition. The quantitative and precise charging system was implemented with the change of filling time and monitoring/controlling/correction of flow rate. Moreover, a dual controller of the high-speed pulse output was established and a high-speed data processing/flow rate charging algorithm was applied in the system. The filling variation of the system was in the range of ±3 gram(gr) (standard deviation 0.57). The developed system could be applied to improve the quality of goods and economic feasibility at various industrial sectors.

A novel ram-air plasma synthetic jet actuator for near space high-speed flow control

2017 ◽  
Vol 133 ◽  
pp. 95-102 ◽  
Author(s):  
Yan Zhou ◽  
Zhixun Xia ◽  
Zhenbing Luo ◽  
Lin Wang ◽  
Xiong Deng
Keyword(s):  
Flow Control ◽  
High Speed ◽  
Synthetic Jet ◽  
Air Plasma ◽  
High Speed Flow ◽  
Synthetic Jet Actuator ◽  
Near Space ◽  
Speed Flow

Three-Electrode Plasma Synthetic Jet Actuator for High-Speed Flow Control

AIAA Journal ◽  
2014 ◽  
Vol 52 (4) ◽  
pp. 879-882 ◽  
Author(s):  
Lin Wang ◽  
Zhi-xun Xia ◽  
Zhen-bing Luo ◽  
Jun Chen
Keyword(s):  
Flow Control ◽  
High Speed ◽  
Synthetic Jet ◽  
High Speed Flow ◽  
Synthetic Jet Actuator ◽  
Speed Flow

Visual Observation and Analysis of Hydrodynamic Structure of Water Jet in Application to Jet Grouting

2007 ◽  
Author(s):  
Hiroshi Yoshida ◽  
Kennosuke Uemura ◽  
Kenji Yoshida ◽  
Isao Kataoka
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
Visual Observation ◽  
Water Jet ◽  
Structure Of Water ◽  
Jet Grouting ◽  
Hydrodynamic Structure ◽  
Jet Velocity ◽  
Very High

Water jet is utilized in various industrial application such as cutting carious materials and soil. In particular, jet grouting for soil improvement is one of the most important application of water jet under high pressure and high liquid flow rate. Such technology is already in practical use in civil engineering. In order to improve the efficiency and performance of jet grouting, it is quite important to clarify the hydrodynamic structure of water jet under high pressure and high flow rate. However, basic researches on this subject are quite insufficient both experimentally and analytically. Water jet utilized in jet grouting is usually very high speed ( up to 500 m/s) two-phase dispersed flow. Therefore, it is quite difficult to make visual observation of such water jet using conventional optical methods. In the present work, the authors utilized high sensitive CCD camera with image intensifier of which gate speed is 10 ns. Using this optical device, the authors obtained still image of high speed water jet for the first time. Visual observation revealed that high speed water jet is composed of very fine droplets and has complicated structures such as swirl and cluster of droplets. Velocity of water jet was also measured using two consecutive images taken between 10 microsecond. Such direct measurement of jet velocity of high speed water jet has not been carried out so far. The result indicated that jet speed (droplet speed) is even very high even at the boundary of water jet. Measure water jet velocity was reasonably correlated with jet velocity at the exit of nozzle.

scholarly journals On the Ejection of Filaments of Polymer Solutions Triggered by a Micrometer-Scale Mixing Mechanism

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3399
Author(s):  
Fernando Marín-Brenes ◽  
Jesús Olmedo-Pradas ◽  
Alfonso M. Gañán-Calvo ◽  
Luis Modesto-López
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
High Speed ◽  
Large Scale ◽  
Liquid Flow Rate ◽  
Scaling Law ◽  
Feeding Tube ◽  
Scale Production ◽  
High Speed Imaging ◽  
Poly Ethylene

Polymer filaments constitute precursor materials of so-called fiber mats, ubiquitous structures across cutting-edge technological fields. Thus, approaches that contribute to large-scale production of fibers are desired from an industrial perspective. Here, we use a robust liquid atomization device operated at relatively high flow rates, ~20 mL/min, as facilitating technology for production of multiple polymer filaments. The method relies on a turbulent, energetically efficient micro-mixing mechanism taking place in the interior of the device. The micro-mixing is triggered by radial implosion of a gas current into a liquid feeding tube, thus resulting in breakup of the liquid surface. We used poly(ethylene oxide) solutions of varying concentrations as test liquids to study their fragmentation and ejection dynamics employing ultra-high speed imaging equipment. Taking an energy cascade approach, a scaling law for filament diameter was proposed based on gas pressure, liquid flow rate and viscosity. We find that a filament dimensionless diameter, Df*, scales as a non-dimensional liquid flow rate Q* to the 1/5. The study aims to elucidate the underlying physics of liquid ejection for further applications in material production.

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