scholarly journals Experimental investigation of free surface vortices and definition of gas entrainment occurrence maps

2014 ◽  
Vol 501 ◽  
pp. 012019 ◽  
Author(s):  
G Caruso ◽  
L Cristofano ◽  
M Nobili ◽  
D Vitale Di Maio
Keyword(s):  
Experimental Investigation ◽  
Free Surface ◽  
Gas Entrainment ◽  
Definition Of

Base-Vented Hydrofoils of Finite Span Under a Free Surface: An Experimental Investigation

1984 ◽  
Vol 28 (02) ◽  
pp. 90-106
Author(s):  
Jacques Verron ◽  
Jean-Marie Michel
Keyword(s):  
Experimental Investigation ◽  
Free Surface ◽  
Flow Rate ◽  
Cavity Length ◽  
Three Dimensional ◽  
Leading Edge ◽  
Pulsation Frequency ◽  
Cavity Pressure ◽  
Air Flow Rate ◽  
Cavity Configuration

Experimental results are given concerning the behavior of the flow around three-dimensional base-vented hydrofoils with wetted upper side. The influence of planform is given particular consideration so that the sections of the foils are simple wedges with rounded noses. Results concern cavity configuration, the relation between the air flow rate and cavity pressure, leading-edge cavitation, cavity length, pulsation frequency, and force coefficients.

Evaluation of the Solid Boundary Treatment Methods in SPH

2018 ◽  
Vol 01 (02) ◽  
pp. 1840002 ◽  
Author(s):  
Shilong Liu ◽  
Ioan Nistor ◽  
Majid Mohammadian
Keyword(s):  
Free Surface ◽  
Free Water ◽  
Treatment Method ◽  
Free Surface Flows ◽  
Solid Boundary ◽  
Surface Flows ◽  
Boundary Treatment ◽  
Particle Hydrodynamics ◽  
Source Models ◽  
Definition Of

The smoothed particle hydrodynamics (SPH) method has been proved as a powerful algorithm for fluid mechanics, especially in the simulation of free surface flows with high speeds or drastic impacts. The solid boundary treatment method is important for the accuracy and stability of the numerical results, as the support domain of fluid particles is truncated near the vicinity of the boundary. This paper presents two commonly used methods for simulating a solid boundary in SPH simulations. Emphasis is placed on the description of the methods, definition of the boundary particles’ parameters, and discussion of their advantages and shortcomings. The classical dam break simulation is conducted using self-developed code and open source models such as DualSPHysics and PySPH in order to investigate the effects of the boundary methods. The results show that methods based on dynamic boundary particles can simulate the free water surface well with a good agreement with experimental results. The conclusions can also be used in research for boundary implementation methods for practical ocean and coastal engineering problems with free surface flows.

Experimental Investigation of Free Surface Gradients in a 90° Angled Asymmetrical Open Channel Confluence

2018 ◽  
pp. 803-819 ◽  
Author(s):  
Stéphan Creëlle ◽  
Lukas Engelen ◽  
Laurent Schindfessel ◽  
Pedro X. Ramos ◽  
Tom De Mulder
Keyword(s):  
Experimental Investigation ◽  
Free Surface ◽  
Open Channel ◽  
Channel Confluence

An Experimental Investigation of Free Surface Transport, Bifurcation, and Adhesion Phenomena as Related to a Hollow Glass Ampule and a Metallic Conductor

1992 ◽  
Vol 114 (3) ◽  
pp. 743-751 ◽  
Author(s):  
S. C. Chen ◽  
K. Vafai
Keyword(s):  
Experimental Investigation ◽  
Free Surface ◽  
Surface Transport ◽  
Fiber Production ◽  
Hollow Glass ◽  
Physical Mechanisms ◽  
Glass Ampule ◽  
Glass Processing ◽  
Metallic Conductor ◽  
Basic Understanding

An experimental investigation of free surface transport and subsequent bifurcation and adhesion for a hollow glass ampule is presented in this work. Detailed phenomenological features of the process are displayed and discussed. This experimental investigation, which is generic in nature, provides the much needed phenomenological information on free surface transport, glass processing as related to optical fiber production, and glass-to-metal sealing processes. Detailed images of the actual sealing process provide valuable information on identifying and isolating the key regimes in the process and mapping out process defects, and contribute to a basic understanding of the physical mechanisms involved in the sealing process.

Measurement of Gas Entrainment Rate From Free Surface by Vortex

2012 ◽  
Author(s):  
Yasuo Koizumi ◽  
Naosuke Ohte ◽  
Kamide Hideki ◽  
Shuji Ohno ◽  
Kei Ito
Keyword(s):  
Free Surface ◽  
High Speed ◽  
Silicone Oil ◽  
Liquid Velocity ◽  
Liquid Level ◽  
Test Fluid ◽  
Entrainment Rate ◽  
Flow State ◽  
Gas Entrainment ◽  
Test Vessel

A sodium-cooled fast breeder reactor is now at the developing stage in Japan. One concern for safety is cover gas entrainment into the sodium coolant. The gas entrainment rate into liquid by the vortex formed on the free surface was examined experimentally. Liquid flowed into a cylindrical vessel from a wall tangentially. Swirl flow was formed in the vessel, and then liquid drained from the bottom outlet of the vessel. A hollow vortex was formed on the free surface in the test vessel. Air was entrained under the free surface of the vortex and carried away from the bottom of the vessel. The flow state of the gas entrainment was visually observed by using a high speed video camera. The gas entrainment rate into liquid was measured. In the present experiments, test fluid was changed from water in the previous experiments to 20 cSt silicone oil. The liquid level in the test vessel was 25 mm in the present experiments. Only the vortex-type gas-entrainment was observed as in the previous experiments since the liquid level was low. The flow state observed at the flow visualization section of the outlet pipe was only a semi-annular flow. The initiation of the gas entrainment was delayed in the case of silicone oil compared with the case of water. The increasing rate of the gas entrainment to the liquid velocity is milder in the case of silicone oil than in the case of water.

Experimental Investigation of the Flow With a Free Surface in an Impulsively Rotating Cylinder

1991 ◽  
Vol 113 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Sangmin Choi ◽  
Jae Won Kim ◽  
Jae Min Hyun
Keyword(s):  
Image Processing ◽  
Experimental Investigation ◽  
Free Surface ◽  
Processing Technique ◽  
Velocity Shear ◽  
Image Processing Technique ◽  
Laser Doppler Velocimeter ◽  
Numerical Predictions ◽  
Shear Front ◽  
Propagating Shear

An experimental investigation was made of the impulsive spin-up from rest of a liquid in a partially filled cylindrical container. The main impetus was placed on delineating the effects of the presence of a free surface on the transient development of flow. Of particular interest were the situations in which the free surface intersected either or both of the endwall disks during the course of spin-up. Extensive flow visualizations were carried out by using suspended metal particles. An image processing technique was utilized to determine accurately the propagating velocity shear front as well as the time-dependent free surface contour. Precise measurements of the fluids velocities were obtained by using a laser Doppler velocimeter. The transient velocity profiles were mapped out, and they were found to be in satisfactory agreement with the predictions based on the simplified analysis. The radial location, Rs(t), of the propagating shear front was measured by applying the image processing technique to the visualized azimuthal flow field. The experimental data were found to be consistent with the numerical predictions.

scholarly journals Moving particle semi-implicit method with improved pressures stability properties

2017 ◽  
Vol 20 (6) ◽  
pp. 1268-1285 ◽  
Author(s):  
Masoud Arami Fadafan ◽  
Masoud-Reza Hessami Kermani
Keyword(s):  
Free Surface ◽  
Kernel Functions ◽  
Original Form ◽  
Test Case ◽  
Mps Method ◽  
Time Flow ◽  
Dummy Particles ◽  
Moving Particle ◽  
The Stability ◽  
Definition Of

Abstract Moving particle semi-implicit (MPS) method is one of the Lagrangian methods widely used in engineering issues. This method, however, suffers from unphysical oscillations in its original form. In the present study, a modified incompressible MPS method is proposed to suppress these oscillations and is used for simulating free surface problems. To demonstrate the stability of the presented method, different kernel functions are used in the case of numerical dam break modeling as a benchmark simulation. A simple form of definition of curved wall boundaries is suggested which eliminates dummy particles and subsequently saves CPU time. Flow over an ogee spillway is simulated for the first time with the I-MPS method and as a new test case which has several curved lines in its geometry. The comparisons between theoretical solutions/experimental data and simulation results in terms of free surface and pressure show the accuracy of the method.

Experimental Investigation of Single-Phase Micro Jets Impingement Cooling for Electronic Applications

2003 ◽  
Author(s):  
Matteo Fabbri ◽  
Shanjuan Jiang ◽  
Vijay K. Dhir
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Free Surface ◽  
Single Phase ◽  
Impinging Jets ◽  
Heat Fluxes ◽  
Number Range ◽  
Impingement Cooling ◽  
Circular Arrays

Impinging jets for cooling of electronic equipment have been used by many researchers. Only few studies using arrays composed of a small number of jets are available in the literature. When very small jet diameters are used, the jet Reynolds number becomes quite small and no data are available for Reynolds number values below 500. In this work attention has been focused on circular arrays of free surface micro jets. Experiments were conducted by employing three jet pitches, 1, 2 and 3 mm and four jet diameters 50, 100, 150 and 250 μm and two different fluids, DI water and FC 40. The jet Reynolds number range was varied between 90 and 2000 while the Prandtl number varied from 6 to 84. Heat fluxes as high as 250 W/cm2 could be removed when water was utilized. Experimental data have been correlated within ±20%.

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