Formation Characteristics of Two-Phase Drops From Coaxial Nozzles

2019 ◽  
Author(s):  
Naoya Kamatani ◽  
Satoshi Ogata
Keyword(s):  
Numerical Analysis ◽  
Newtonian Fluid ◽  
Single Layer ◽  
Theoretical Expression ◽  
Liquid Droplets ◽  
Two Phase ◽  
Coaxial Nozzle ◽  
Outer Interface ◽  
Conditional Expression ◽  
Production Conditions

Abstract The purpose of this study is to clarify the formation characteristics and production conditions of two-layer droplets using coaxial nozzle. In this study, we focus on Newtonian fluid only to pay attention to the fundamental formation characteristics of two-layer droplet. Also, the three liquids flowing in the apparatus were assumed to have the same viscosity and density. First, theoretical equations concerning the outer diameters of the single layer droplet and the two-layer droplet were obtained, and a conditional expression for detaching both nozzles simultaneously from the nozzle in dripping was obtained. These theoretical equations were verified using numerical analysis. By analyzing with various parameters changed, the following six formation modes could be confirmed. 2 interface both dripping, 2 interface both jetting, Outer interface is jetting and The inner interface is dripping, 2 interface comes into contact and the encapsulated liquid is discharged to the outside, Two or more droplets are formed in the interior, Liquid droplets containing liquid droplets and liquid droplets not containing liquid droplets are alternately formed. The validity of each theoretical expression and conditional expression was also be confirmed.

NUMERICAL ANALYSIS OF DUAL TWO-PHASE DISCHARGE FROM A HEADER

2018 ◽  
Author(s):  
M. K. Guyot ◽  
Scott J. Ormiston ◽  
Hassan M. Soliman
Keyword(s):  
Numerical Analysis ◽  
Two Phase

NUMERICAL ANALYSIS OF NEWTONIAN FLUID FLOW VARYING THE CONTRACTION GEOMETRY USING OPENFOAM

2019 ◽  
Author(s):  
João Pedro Costa Eliziário ◽  
andrevidy honório ◽  
Marcos Lourenço ◽  
Elie Luis Martínez Padilla
Keyword(s):  
Fluid Flow ◽  
Numerical Analysis ◽  
Newtonian Fluid

Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

2003 ◽  
Vol 125 (1) ◽  
pp. 103-109 ◽  
Author(s):  
C. Ramaswamy ◽  
Y. Joshi ◽  
W. Nakayama ◽  
W. B. Johnson
Keyword(s):  
Heat Dissipation ◽  
Layer Structure ◽  
Single Layer ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Small Range ◽  
Two Phase ◽  
Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

scholarly journals Modification of Mechanical Properties of High-Strength Titanium Alloys VT23 and VT23M Due to Impact-Oscillatory Loading

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 80 ◽  
Author(s):  
Mykola Chausov ◽  
Janette Brezinová ◽  
Andrii Pylypenko ◽  
Pavlo Maruschak ◽  
Liudmyla Titova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
High Strength ◽  
The Self ◽  
Self Organization ◽  
Two Phase ◽  
Rolled Metal ◽  
Technological Method ◽  
Equilibrium Processes ◽  
Production Conditions

A simple technological method is proposed and tested experimentally, which allows for the improvement of mechanical properties in sheet two-phase high-strength titanium alloys VT23 and VT23M on the finished product (rolled metal), due to impact-oscillatory loading. Under impact-oscillatory loading and dynamic non-equilibrium processes (DNP) are realized in titanium alloys, leading to the self-organization of the structure. As a result, the mechanical properties of titanium alloys vary significantly with subsequent loading after the realization of DNP. In this study, the test modes are found, which can be used in the production conditions.

scholarly journals Numerical Analysis of Bearing Capacity of a Ring Footing on Geogrid Reinforced Sand

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 68
Author(s):  
Haidar Hosamo ◽  
Iyad Sliteen ◽  
Songxiong Ding
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Double Layer ◽  
Practical Importance ◽  
Single Layer ◽  
Outer Diameter ◽  
Storage Container ◽  
Reinforced Sand ◽  
Oil Storage ◽  
Ring Footing

A ring footing is found to be of practical importance in supporting symmetrical constructions for example silos, oil storage container etc. In the present paper, numerical analysis was carried out with explicit code FLAC3D 7.0 to investigate bearing capacity of a ring footing on geogrid reinforced sand. Effects of the ratio n of its inner/outer diameter (Di/D) of a ring footing, an optimum depth to lay the geogrid layer were examined. It was found that an intersection zone was developed in soil under inner-side (aisle) of ring footing, contributing to its bearing capacity. Substantial increase of bearing capacities could be realized if ratio n of a ring footing was around 0.6. Numerical results also showed that, bearing capacity of a ring footing could increase significantly if a single-layer geogrid was laid at a proper depth under the footing. Similar contribution was found if a double-layer geogrid was implemented. However, such increases appeared to be rather limited if a triple-layer geogrid or a four-layer geogrid was used. A double-layer geogrid was recommended to increase the bearing capacity of a ring footing; the depth to lay this double-layer geogrid was also discussed.

Numerical Analysis of Influence of Roughness of Material Surface on High-Speed Liquid Droplet Impingement

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Hirotoshi Sasaki ◽  
Yuka Iga
Keyword(s):  
Numerical Analysis ◽  
High Speed ◽  
Erosion Rate ◽  
Liquid Droplet ◽  
Material Surface ◽  
Liquid Droplets ◽  
Fluid Machinery ◽  
Droplet Impingement ◽  
Surface Liquid ◽  
Droplet Impingement Erosion

This study explains why the deep erosion pits are formed in liquid droplet impingement erosion even though the droplets uniformly impinge on the entire material surface. Liquid droplet impingement erosion occurs in fluid machinery on which droplets impinge at high speed. In the process of erosion, the material surface becomes completely roughened by erosion pits. In addition, most material surface is not completely smooth and has some degree of initial roughness from manufacturing and processing and so on. In this study, to consider the influence of the roughness on the material surface under droplet impingement, a numerical analysis of droplets impinging on the material surface with a single wedge and a single bump was conducted with changing offsets between the droplet impingement centers and the roughness centers on each a wedge bottom and a bump top. As results, two mechanisms are predicted from the present numerical results: the erosion rate accelerates and transitions from the incubation stage to the acceleration stage once roughness occurs on the material surface; the other is that deep erosion pits are formed even in the case of liquid droplets impinging uniformly on the entire material surface.

scholarly journals Buckling folds of a single layer embedded in matrix – Folding behavior revealed by numerical analysis

2010 ◽  
Vol 32 (7) ◽  
pp. 960-974 ◽  
Author(s):  
Kuo-Pin Huang ◽  
Kuo-Jen Chang ◽  
Tai-Tien Wang ◽  
Fu-Shu Jeng
Keyword(s):  
Numerical Analysis ◽  
Single Layer
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