Flow Visualization Pattern on Sharp Edge T-Junction through Dividing Flow Channel

2014 ◽  
Vol 493 ◽  
pp. 62-67 ◽  
Author(s):  
Y.B. Lukiyanto ◽  
I.N.G. Wardana ◽  
Widya Wijayanti ◽  
M. Agus Choiron
Keyword(s):  
Flow Visualization ◽  
Flow Pattern ◽  
Flow Model ◽  
Flow Channel ◽  
Sharp Edge ◽  
Inlet Flow ◽  
Head Losses ◽  
Model Scale ◽  
Outlet Flow ◽  
Static Conditions

In the previous study, sharp edge T-junction had been investigated to determine head losses and flow pattern. In this study, sharp edge T-junction was used as inlet flow model scale to determine flow visualization pattern. The apparatus test provide a dividing flow channel on static conditions which is the inlet pressure larger than 1 atm. Pressure difference is measured by using a U-pipe manometer. The manometer was inserted between inlet and outlet. Flow rate is measured by collecting fluid into a measuring cup. The coefficient of losses is determined as a result for predicting the losses energy. Flow Visualization Pattern is one of solution to perform the mechanism of sharp edge T-junction as inlet flow model scale. The result shows that flow pattern from simulation has the same trend with experimental results.

Characterization and Optimization of the Flow Pattern Inside a Diaphragm Blood Pump Based on Flow Visualization Techniques

ASAIO Journal ◽  
1998 ◽  
Vol 44 (5) ◽  
pp. M714-M718 ◽  
Author(s):  
Masako Nakata ◽  
Toru Masuzawa ◽  
Eisuke Tatsumi ◽  
Yoshiyuki Taenaka ◽  
Takashi Nishimura ◽  
...  
Keyword(s):  
Flow Visualization ◽  
Flow Pattern ◽  
Blood Pump ◽  
Visualization Techniques

scholarly journals Infiltration and Anti-Filtration Recharge-Pumping Well and Laboratory Recharge Tests

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1834
Author(s):  
Yuxi Li ◽  
Wanglin Li ◽  
Jiapeng He ◽  
Xiaojiao Zhang ◽  
Xinyi Li
Keyword(s):  
Steady State ◽  
Flow Pattern ◽  
Theoretical Equation ◽  
Steady State Flow ◽  
Inlet Flow ◽  
State Flow ◽  
Unconfined Aquifers ◽  
Pumping Wells ◽  
Single Well

Infiltration and anti-filtration recharge-pumping wells (hereinafter, referred to as IAF recharge-pumping wells) can enable rain-flood flowing in rivers or channel recharge to aquifers, in flood periods, and pump groundwater to be utilized in non-flood periods. In this study, a round IAF recharge-pumping well and a square IAF recharge-pumping well were developed, the structure and characteristic were introduced, the calculation equations of single-well recharge quantity of IAF recharge-pumping wells, in unconfined aquifers were deduced, and the steady-state flow recharge test was conducted in the laboratory. The conclusions were as follows. The theoretical equation of the single-well recharge quantity was reasonable. Compared to existing anti-filtration recharge wells, the new IAF recharge-pumping well had stronger anti-deposit and anti-scour abilities and the single-well recharge quantity increased by 400%. Compared to the square IAF recharge-pumping well, the round IAF recharge-pumping well had a better inlet flow pattern and a larger single-well recharge quantity. With an increase in the test times, the single-well recharge quantity gradually decreased and tended to be stable. The existence of the pumping pipe had a little influence on the single-well recharge quantity.

scholarly journals Direct Observation of Filling Process and Porosity Prediction in High Pressure Die Casting

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1099 ◽  
Author(s):  
Hanxue Cao ◽  
Chao Shen ◽  
Chengcheng Wang ◽  
Hui Xu ◽  
Juanjuan Zhu
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Visualization ◽  
Flow Pattern ◽  
Experimental Verification ◽  
Die Casting ◽  
Filling Process ◽  
High Pressure Die Casting ◽  
Visualization Experiment ◽  
Pressure Die Casting

Although numerical simulation accuracy makes progress rapidly, it is in an insufficient phase because of complicated phenomena of the filling process and difficulty of experimental verification in high pressure die casting (HPDC), especially in thin-wall complex die-castings. Therefore, in this paper, a flow visualization experiment is conducted, and the porosity at different locations is predicted under three different fast shot velocities. The differences in flow pattern between the actual filling process and the numerical simulation are compared. It shows that the flow visualization experiment can directly observe the actual and real-time filling process and could be an effective experimental verification method for the accuracy of the flow simulation model in HPDC. Moreover, significant differences start to appear in the flow pattern between the actual experiment and the Anycasting solution after the fragment or atomization formation. Finally, the fast shot velocity would determine the position at which the back flow meets the incoming flow. The junction of two streams of fluid would create more porosity than the other location. There is a transition in flow patterns due to drag crisis under high fast shot velocity around two staggered cylinders, which resulted in the porosity relationship also changing from R1 < R3 < R2 (0.88 m/s) to R1 < R2 < R3 (1.59 and 2.34 m/s).

Flow Visualization Study of Jet and Bucket Interactions in Traditional and Hooped Pelton Runner

2019 ◽  
Author(s):  
Gaurangkumar Chaudhari ◽  
Salim Channiwala ◽  
Samip Shah ◽  
Digvijay Kulshreshtha
Keyword(s):  
Flow Visualization ◽  
Flow Pattern ◽  
High Speed ◽  
Early Stage ◽  
Small Scale ◽  
High Speed Photography ◽  
Pelton Turbine ◽  
Single Jet ◽  
Absolute Frame ◽  
First Time

Abstract This paper aims to study the flow pattern in and around a bucket of a Traditional and a Hooped Pelton runner at single injector operation and illustrates different stages of jet interaction. High speed photography is used to study the flow pattern, keeping the camera in different positions relative to the jet and to the bucket. It is concluded from the results that the flow visualization study, provides exceptional observations with an absolute frame of reference to mark the bucket duty period of a single-jet Pelton runner. The small scale models display erosion damages at the bucket lips, this indicated that the high pressure occur in the early stage of interaction. This fact is substantiated by the present flow visualization studies for the first time. The uncertainty of the free surface outflow within the Pelton turbine bucket establishes good documentation. The results are helpful to know the interaction between the jet and bucket of Pelton turbine.

Surrogate Models for Predicting the Performance of a Liquid-Liquid Cylindrical Cyclone Separator

2006 ◽  
Author(s):  
Jorge E. Pacheco ◽  
Miguel A. Reyes
Keyword(s):  
Flow Pattern ◽  
Mean Squared Error ◽  
Surrogate Models ◽  
Mechanistic Models ◽  
Water Mixture ◽  
Inlet Flow ◽  
Prediction Tools ◽  
Squared Error ◽  
Cylindrical Cyclone ◽  
Oil Water

Liquid-Liquid Cylindrical Cyclone (LLCC) separators are devices used in the petroleum industry to extract a portion of the water from the oil-water mixture obtained at the well. The oil-water mixture entering the separator is divided due to centrifugal and buoyancy forces in an upper (oil rich) exit and a bottom (water rich) exit. The advantages in size and cost compared with traditional vessel type static separators are significant. The use of LLCC separators has not been widespread due to the lack of proven performance prediction tools. Mechanistic models have been developed over the years as tools for predicting the behavior of these separators. These mechanistic models are highly dependent on the inlet flow pattern prediction. Thus, for each specific inlet flow pattern a sub-model has to be developed. The use of surrogate models will result in prediction tools that are accurate over a wider range of operational conditions. We propose in this study to use surrogate models based on a minimum-mean-squared-error method of spatial prediction known as Kriging. Kriging models have been used in different applications ranging from structural optimization, conceptual design, multidisciplinary design optimization to mechanical and biomedical engineering. These models have been developed for deterministic data. They are targeted for applications where the available information is limited due to the cost of the experiments or the time consumed in numerical simulations. We propose to use these models with a different framework so that they can manage information from replications. For the LLCC separator a two-stage surrogate model is built based on the Bayesian surrogate multistage approach, which allows for data to be incorporated as the model is improved. Cross validation mean squared error measurements are analyzed and the model obtained shows good predicting capabilities. These surrogate models are efficient and versatile predicting tools that do not require information about the physical phenomena that drives the separation process.

Flow Behavior and Flow Boiling Heat Transfer in Thin-Rectangular Mini-Channels

2008 ◽  
Author(s):  
Yasuo Koizumi ◽  
Hiroyasu Ohtake ◽  
Tomonari Yamada
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Pattern ◽  
Critical Heat Flux ◽  
Boiling Heat Transfer ◽  
Annular Flow ◽  
Flow Channel ◽  
Heat Transfer Surface ◽  
Liquid Slug ◽  
Flux Condition

Boiling heat transfer of thin-rectangular channels of the width of 10 mm has been examined. The height of the flow channel was in a range from 0.6 mm to 0.4 mm. Experimental fluid was water. Bubbly flow, slug flow, semi annular flow and annular flow were observed. The flow pattern transition agreed well with the Baker flow pattern map for the usual sized flow path. The critical heat flux was lower than the value of the usual sized flow channel. The Koizumi and Ueda method predicted well the trend of the critical heat flux of the present experiments. At the critical heat flux condition, the heat transfer surface was covered by liquid slug, a large bubble pushed away the liquid slug, a dry area was formed on the heat transfer surface and then liquid slug came around to cover the heat transfer surface again. This process repeated rapidly. Following this observation, a heat transfer surface temperature calculation model at the critical heat flux condition was proposed. The calculated result re produced the experimental result.

Effect of Deflected Inflow on Flows in a Strongly-Curved 90 Degree Elbow

2015 ◽  
Author(s):  
Yukiharu Iwamoto ◽  
Ryo Kusuzaki ◽  
Motosuke Sogo ◽  
Kazunori Yasuda ◽  
Hidemasa Yamano ◽  
...  
Keyword(s):  
Flow Visualization ◽  
Pressure Distribution ◽  
Reynolds Numbers ◽  
Bulk Velocity ◽  
Curvature Radius ◽  
Inlet Flow ◽  
Pressure Region ◽  
Spectral Density Functions ◽  
Inner Diameter ◽  
Flow Case

Wall pressure measurements and flow visualization were conducted for a 90 degree elbow with an axis curvature radius the same as its inner diameter (125 mm, Rc/D = 1). Reynolds numbers 320,000 and 500,000, based on the inner diameter and bulk velocity, were examined. A deflected inflow, having an almost constant velocity slope, was introduced in the present study. The velocity at the inside was 20% faster than the bulk velocity in the plane one diameter upstream of the elbow inlet. Ensemble averaged pressure distributions showed that no difference of normalized pressure could be found in cases of Reynolds numbers of 320,000 and 500,000. Comparisons with a uniform inlet flow case [1] proved that a low-pressure region at the intrados of the elbow was weakened and that a high-pressure region outside strengthened in the deflected inflow case. The present case had a characteristic pressure distribution that the pressure downstream of the elbow increased at the inside until two diameters downstream from the elbow exit. Flow visualization concluded that the corresponding pressure increase was caused by a collision of a strengthened secondary flow convected from the extrados. The unsteady pressure distribution in the present case showed that a circumferential extent of a strongly fluctuating region in the inside and downstream of the elbow decreased, comparing with the uniform inlet flow case.[1] Power spectral density functions of pressures exhibited that the fluctuation having the Strouhal number (based on the inner diameter and bulk velocity) of 0.6 existed in the downstream region of the elbow, which is 0.1 larger than that of the uniform inflow case.

scholarly journals Evaluation of a Desktop 3D Printed Rigid Refractive-Indexed-Matched Flow Phantom for PIV Measurements on Cerebral Aneurysms

2019 ◽  
Vol 11 (1) ◽  
pp. 14-23 ◽  
Author(s):  
W. H. Ho ◽  
I. J. Tshimanga ◽  
M. N. Ngoepe ◽  
M. C. Jermy ◽  
P. H. Geoghegan
Keyword(s):  
3D Printing ◽  
Flow Visualization ◽  
Investment Casting ◽  
Flow Model ◽  
Low Cost ◽  
Ammonium Thiocyanate ◽  
Cerebral Aneurysms ◽  
Model Material ◽  
Flow Phantom ◽  
3D Printed

Abstract Purpose Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication. Methods Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin. Results An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH4SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies. Conclusions This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.

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