scholarly journals Determination of Mist Flow Characteristic for MQL Technique Using Particle Image Velocimetry (PIV) and Computer Fluid Dynamics (CFD)

2015 ◽  
Vol 773-774 ◽  
pp. 403-407 ◽  
Author(s):  
E.A. Rahim ◽  
Hemarani Dorairaju ◽  
Norzilawati Asmuin ◽  
M.H.A.R. Mantari
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Pattern ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Cutting Temperature ◽  
Machining Process ◽  
Cutting Fluid ◽  
Minimum Quantity ◽  
Image Velocimetry ◽  
Mist Flow

In recent years, minimum quantity lubrication (MQL) machining is regarded as a promising method for reducing machining cost and cutting fluid, while improving cutting performance. However the effectiveness and the working principle of MQL are still questionable with very few explanations provided. The aim of this study is to determine the optimum distance between the nozzle and tool tip and appropriate flow pattern of the mist flow for minimum quantity lubricant using Particle Image Velocimetry (PIV) and Computer Fluid Dynamic (CFD) for optimizing the spraying conditions thus reducing the lubricant consumption. The spray from the nozzle with outlet diameter of 2.5mm is analysed using Particle Image Velocimetry (PIV) to measure the mist flow velocity and identify the flow pattern. The input pressure of 0.2, 0.3 and 0.4MPa will be discharged throughout the experiment. Higher pressure produce more mass flow rate which helps in reducing the cutting force and cutting temperature efficiently and prolong tool life. Thus the appropriate distance can reduce lubricant consumption and increase the cooling and lubricating ability with best nozzle position. The applied distance increases the efficiencies of MQL applied during machining process.

An Experimental Study on the Performance of Drag-Reducing Polymers in Single- and Multiphase Horizontal Flow Using Particle Image Velocimetry

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Ihab H. Alsurakji ◽  
A. Al-Sarkhi ◽  
M. Habib ◽  
Hassan M. Badr
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Pipe Wall ◽  
Fluid Dynamic ◽  
Water Soluble ◽  
Experimental Investigations ◽  
Two Phase ◽  
Image Velocimetry ◽  
Flow Field Characteristics ◽  
Phase Water

This paper presents experimental investigations conducted to understand the influence of water-soluble drag-reducing polymers (DRPs) in single- and two-phase (stratified wavy) flow on flow-field characteristics. These experiments have been presented for water and air–water flowing in a horizontal polyvinyl chloride 22.5-mm ID, 8.33-m long pipe. The effects of liquid flow rates and DRP concentrations on streamlines and the instantaneous velocity were investigated by using particle image velocimetry (PIV) technique. A comparison of the PIV results was performed by comparing them with the computational results obtained by fluent software. One of the comparisons has been done between the PIV results, where a turbulent flow with DRP was examined, and the laminar–computational fluid dynamic (CFD) prediction. An agreement was found in the region near the pipe wall in some cases. The results showed the powerfulness of using the PIV techniques in understanding the mechanism of DRP in single- and two-phase flow especially at the regions near the pipe wall and near the phases interface. The results of this study indicate that an increase in DRP concentrations results in an increase in drag reduction up to 45% in single-phase water flow and up to 42% in air–water stratified flow.

Particle Image Velocimetry Used to Qualitatively Validate Computational Fluid Dynamic Simulations in an Oxygenator: A Proof of Concept

2015 ◽  
Vol 6 (3) ◽  
pp. 340-351 ◽  
Author(s):  
Peter C. Schlanstein ◽  
Felix Hesselmann ◽  
Sebastian V. Jansen ◽  
Jeannine Gemsa ◽  
Tim A. Kaufmann ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Proof Of Concept ◽  
Dynamic Simulations ◽  
Image Velocimetry

scholarly journals Fluid Dynamic Assessment of Three Polymeric Heart Valves Using Particle Image Velocimetry

2006 ◽  
Vol 34 (6) ◽  
pp. 936-952 ◽  
Author(s):  
Hwa Liang Leo ◽  
Lakshmi Prasad Dasi ◽  
Josie Carberry ◽  
Hélène A. Simon ◽  
Ajit P. Yoganathan
Keyword(s):  
Particle Image Velocimetry ◽  
Heart Valves ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Dynamic Assessment ◽  
Image Velocimetry

Particle Image Velocimetry Measurements in a Representative Gas-Cooled Prismatic Reactor Core Model: Distribution of Flow From the Upper Plenum to the Fuel Block Arrangement

2013 ◽  
Author(s):  
Thomas E. Conder ◽  
Ralph S. Budwig ◽  
Richard S. Skifton
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Fluid Dynamic ◽  
National Laboratory ◽  
Reactor Core ◽  
Flow Distribution ◽  
Flow Rates ◽  
Image Velocimetry ◽  
Direct Support ◽  
Block Arrangement

An experiment was conducted at Idaho National Laboratory to investigate the bypass flow associated with a Gas Turbine-Modular Helium Reactor in direct support of Computational Fluid Dynamic validation [1]. Velocity fields within a representative quartz model, consisting of an upper plenum, upper block, and lower block, were measured using Particle Image Velocimetry; after which, flow rates were calculated in each section. The present study was carried out to determine flow distribution from the upper plenum to the fuel block assembly. It was found that the flow rates in the lower six coolant channels varied from their average only by 2.4, 4.6, and 2.5% for the low, medium, and high flow cases, respectively. Consequently, it was concluded that the non-uniform inlet velocity condition in the upper plenum had insignificant effect on flow distribution to the coolant channels and interstitial gap.

Flow Structures in a U-Shaped Fuel Cell Flow Channel: Quantitative Visualization Using Particle Image Velocimetry

2004 ◽  
Vol 2 (1) ◽  
pp. 70-80 ◽  
Author(s):  
J. Martin ◽  
P. Oshkai ◽  
N. Djilali
Keyword(s):  
Particle Image Velocimetry ◽  
Fuel Cell ◽  
Cross Sections ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Vortex Formation ◽  
Image Velocimetry ◽  
Quantitative Visualization ◽  
Image Density ◽  
Transport Channels

Flow through an experimental model of a U-shaped fuel cell channel is used to investigate the fluid dynamic phenomena that occur within serpentine reactant transport channels of fuel cells. Achieving effective mixing within these channels can significantly improve the performance of the fuel cell and proper understanding and characterization of the underlying fluid dynamics is required. Classes of vortex formation within a U-shaped channel of square cross section are characterized using high-image-density particle image velocimetry. A range of Reynolds numbers, 109⩽Re⩽872, corresponding to flow rates encountered in a fuel cell operating at low to medium current densities is investigated. The flow fields corresponding to two perpendicular cross sections of the channel are characterized in terms of the instantaneous and time-averaged representations of the velocity, streamline topology, and vorticity contours. The critical Reynolds number necessary for the onset of instability is determined, and the two perpendicular flow planes are compared in terms of absolute and averaged velocity values as well as Reynolds stress correlations. Generally, the flow undergoes a transition to a different regime when two recirculation zones, which originally develop in the U-bend region, merge into one separation region. This transition corresponds to generation of additional vortices in the secondary flow plane.

Flow Pattern Evolution With Time Mixing of Non-Newtonian Fluid in a Stirred Tank Using Particle Image Velocimetry

Volume 1 ◽  
2004 ◽  
Author(s):  
E. Fransolet ◽  
P. Marchot ◽  
D. Toye ◽  
M. Crine
Keyword(s):  
Aqueous Solution ◽  
Particle Image Velocimetry ◽  
Flow Pattern ◽  
Newtonian Fluid ◽  
Particle Image ◽  
Mixing Time ◽  
Time Dependent ◽  
Stirred Tank ◽  
Image Velocimetry ◽  
Evolution With Time

This paper presents an experimental analysis of the evolution with time of the flow pattern in a stirred tank equipped with a rotor-stator mixer, when mixing a time dependent non-Newtonian fluid. Particle image velocimetry (PIV) is used to determine 2D velocity maps. Polyacrylamide (PAAm) aqueous solution is used as model of time dependent shear thinning fluids. Creep compliance and recovery tests are performed to follow the evolution of the fluid rheology, from a viscoelastic behaviour to a purely viscous one. This indicates mixing has almost completely destroyed the initial network structure of the non-Newtonian fluid. The evolution of the flow pattern with the mixing time is compared with the flow patterns obtained in presence of Newtonian fluids as water and glycerol aqueous solution.

Particle Image Velocimetry Measurement and Computational Fluid Dynamic Simulations of the Unsteady Flow Within a Rotating Disk Cavity

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Xiang Luo ◽  
Dongdong Liu ◽  
Hongwei Wu ◽  
Zhi Tao
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Turbine Rotor ◽  
Dynamic Simulations ◽  
Image Velocimetry ◽  
The Impact

In this article a combined experimental and numerical investigation of the unsteady mixing flow of the ingestion gas and rim sealing air inside a rotating disk cavity was carried out. A new test rig was set up, and the experiments were conducted on a 1.5-stage turbine rotor disk and included pressure measurements. The flow structure of the mixing region of the ingestion gas and sealing air in cavity was measured using the particle image velocimetry (PIV) technique. To complement the experimental investigation and to aid in understanding the flow mechanism within the cavity, a three-dimensional (3D) unsteady computational fluid dynamic (CFD) analysis was undertaken. Both simulated and experimental results indicated that near the rotating disk, (i) a large amount of the ingestion gas will turn around and flow out the cavity due to the impact of the centrifugal force and the Coriolis force, (ii) a small amount of ingestion gas will mix transiently with the sealing air inside the cavity, whereas near the static disk, (iii) the ingestion gas will flow into the cavity along the static wall and mix with the sealing air.

PIV Analysis of the Flow Pattern Around an Ablation Catheter to Observe the Flow Effect on the Electrode

2013 ◽  
Author(s):  
Kaihong Yu ◽  
Tetsui Yamashita ◽  
Shigeaki Shingyochi ◽  
Kazuo Matsumoto ◽  
Makoto Ohta
Keyword(s):  
Blood Flow ◽  
Particle Image Velocimetry ◽  
Catheter Ablation ◽  
Flow Pattern ◽  
Open Channel ◽  
Particle Image ◽  
Circulation System ◽  
Convection Flow ◽  
Image Velocimetry ◽  
Catheter Tip

Radiofrequency (RF) catheter ablation is a highly effective treatment for many cardiac arrhythmias, especially for tachyarrhythmia. RF energy is introduced through the catheter onto the endocardial surface to destroy the abnormal heart tissue causing the heart rhythm disorder. Many parameters relate to myocardial temperature, such as RF power, tissue contact, and blood flow. Blood flow is an important factor that has a cooling effect on myocardium and affects the final lesion size. Many previous studies have shown that under temperature control, lesion sizes are larger and tissue temperatures rise faster with a high flow rate. If the flow causes a decrease in the temperature of the catheter tip, the generator will increase the power output to maintain the tip at a constant temperature. However, few studies of RF catheter ablation have investigated how ablation affects blood flow. Observation of the flow pattern around the catheter can help to determine the mechanism of the flow effects on the temperature of the catheter tip. The purpose of this study is to observe the flow pattern during ablation using an in-vitro circulation system developed for Particle Image Velocimetry (PIV). We developed an open-channel circulation system to simulate blood flow. The mold for the open-channel was built with acrylic boards for transparency. The working fluid was 0.9% saline, which was used at room temperature (20°C). Instead of animal myocardium, we used a poly (vinyl alcohol) hydrogel (PVA-H), which has mechanical characteristics that approximate those of biological soft tissue, and contact with the PVA-H surface by the catheter is similar to that with myocardium. A 7 Fr catheter with a 4-mm ablation electrode tip was set perpendicular to the PVA-H surface, and the contact weight between the electrode of the catheter and the PVA-H surface was 2.2 gf. To measure the temperature profile in the PVA-H, a K-type thermocouple with the diameter of 0.5 mm was placed at the depth of 2 mm from the surface. The thermocouple tip was always placed on the catheter axis. The flow pattern at the location where the catheter was held was observed by a high speed camera, and the resulting images were analyzed by particle image velocimetry (PIV). The results showed that in the absence of applied flow, convection flow from the electrode is observed in the areas around the catheter. However, under a 1.6 L/min flow rate, convection flow disappears. In conclusion, blood flow could decrease the catheter tip temperature, and the influence of ablation in the flow around the catheter disappeared.

scholarly journals Particle Image Velocimetry Measurements in a Representative Gas-Cooled Prismatic Reactor Core Model: Flow in the Coolant Channels and Interstitial Bypass Gaps

2012 ◽  
Author(s):  
Thomas E. Conder ◽  
Richard S. Skifton ◽  
Ralph S. Budwig
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Reactor Core ◽  
Index Of Refraction ◽  
Bypass Flow ◽  
Model Flow ◽  
Image Velocimetry ◽  
Key Issues ◽  
Representative Model

Core bypass flow is one of the key issues with the prismatic Gas Turbine-Modular Helium Reactor, and it refers to the coolant that navigates through the interstitial passages between the graphite fuel blocks instead of traveling through the designated coolant channels. To determine the bypass flow, a double scale representative model was manufactured and installed in the Matched Index-of-Refraction flow facility; after which, stereo Particle Image Velocimetry (PIV) was employed to measure the flow field within. PIV images were analyzed to produce vector maps, and flow rates were calculated by numerically integrating the velocity field. It was found that the bypass flow varied between 6.9–15.8% for channel Reynolds numbers of 1,746 and 4,618 with a 6mm gap. The results were compared to computational fluid dynamic (CFD) pre-test simulations. When compared to these pretest calculations, the CFD analysis appeared to under predict the flow through the gap.

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