An Analysis of Internal Flow Through a Swirl Nozzle with a VOF Model and Its Application to Nozzle Design

2003 ◽  
Vol 2003.3 (0) ◽  
pp. 61-62
Author(s):  
Masaaki KUBO ◽  
Kaori ARAI ◽  
Akihiro SAKAKIDA ◽  
Akihiro IIYAMA
Keyword(s):  
Internal Flow ◽  
Nozzle Design ◽  
Vof Model ◽  
Flow Through

An Analysis of Internal Flow Through a Swirl Injector with a VOF Model

2000 ◽  
Vol 2000.4 (0) ◽  
pp. 313-314
Author(s):  
Masaaki KUBO ◽  
Akihiro SAKAKIDA ◽  
Akihiro IIYAMA ◽  
Nobuo SAKIYAMA
Keyword(s):  
Internal Flow ◽  
Vof Model ◽  
Swirl Injector ◽  
Flow Through

A Numerical Approach for the Simulation of Internal Nozzle Flow in a Pressure Swirl Atomizer Using Different Turbulent Models and Towards an Effective Inlet Weber Number

2013 ◽  
Author(s):  
Ahmadreza Abbasi Baharanchi ◽  
Seckin Gokaltun ◽  
Shahla Eshraghi
Keyword(s):  
Weber Number ◽  
Computational Cost ◽  
Internal Flow ◽  
Numerical Approach ◽  
Reynolds Stress Model ◽  
Multiphase Model ◽  
Vof Model ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

VOF Multiphase model is used to simulate the flow inside a pressure-swirl-atomizer. The capability of the Reynolds Stress Model and variants of the K-ε and K-ω models in modeling of turbulence has been investigated in the commercial computational fluid dynamics (CFD) software FLUENT 6.3. The Implicit scheme available in the volume-of-fluid (VOF) model is used to calculate the interface representation between phases. The atomization characteristics have been investigated as well as the influence of the inlet swirl strength of the internal flow. The numerical results have been successfully validated against experimental data available for the computed parameters. The performance of the RNG K-ε model was found to be satisfactory in reducing the computational cost and introducing an effective Weber number for the flow simulated in this study.

Simulation of the Flow Condition Near the Intake of a Pump Sump

2006 ◽  
Author(s):  
Shuhong Liu ◽  
Yong Li ◽  
Xianwu Luo ◽  
Yulin Wu
Keyword(s):  
Flow Condition ◽  
Water Surface ◽  
Free Water ◽  
Internal Flow ◽  
Free Water Surface ◽  
Pump Station ◽  
Vof Model ◽  
Calculation Results ◽  
Pump Sump ◽  
Steady Simulation

It is known that the flow condition in the pump sump is very complicated, which usually performs as several types of vortex, water wave of free surface, vibration, noise, and etc. To make clear the flow condition experimentally and numerically is very important to develop the performance and operating stability of the pump station. As one of the projects with Hitachi Industries ltd. Co., Japan, the investigation experimentally on the internal flow condition of the pump sump has been carried out in Tsinghua University. In this paper, we introduce the simulation results, which can show more detail information near the intake of the pump sump. The simulation is focused on the area near the intake, together with the extension of up-stream and down-stream. The calculation research includes two parts: steady simulation and unsteady simulation by VOF model, which is provided by the commercial software of Fluent. Through the steady simulation, the distribution of free water surface (water height) near the intake, as well as the flow condition inside the intake, were obtained. Comparing with the experimental data, a good agreement was observed. After analyzing the unsteady calculation results by VOF, four stages of the development of air-entraining vortex, and the wave characteristic of free water surface, were obtained, which were in accord with the experiment visualizing.

scholarly journals The temporal evolution of neutral modes in the impulsively started flow through a circular pipe and their connection to the nonlinear stability of Hagen–Poiseuille flow

2002 ◽  
Vol 457 ◽  
pp. 339-376 ◽  
Author(s):  
ANDREW G. WALTON
Keyword(s):  
Poiseuille Flow ◽  
Multiple Scales ◽  
Stability Boundary ◽  
Circular Cross Section ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Bypass Transition ◽  
Flow Through ◽  
High Reynolds ◽  
Wave Limit

The linear stability of the impulsively started flow through a pipe of circular cross-section is studied at high Reynolds number R. A crucial non-dimensional time of O(R7/9) is identified at which the disturbance acquires internal flow characteristics. It is shown that even if the disturbance amplitude at this time is as small as O(R−22/27) the subsequent evolution of the perturbation is nonlinear, although it can still be followed analytically using a multiple-scales approach. The amplitude and wave speed of the nonlinear disturbance are calculated as functions of time and we show that as t → ∞, the disturbance evolves into the long-wave limit of the neutral mode structure found by Smith & Bodonyi in the fully developed Hagen–Poiseuille flow, into which our basic flow ultimately evolves. It is proposed that the critical amplitude found here forms a stability boundary between the decay of linear disturbances and ‘bypass’ transition, in which the fully developed state is never attained.

scholarly journals Design of Pressurized Metered Dose Inhalers Modeling of Internal Flow and Atomization

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Henk Versteeg ◽  
Abdul Qaiyum Shaik
Keyword(s):  
Experimental Work ◽  
Equilibrium Model ◽  
Lung Diseases ◽  
Internal Flow ◽  
Flow Conditions ◽  
Metered Dose Inhalers ◽  
Numerical Predictions ◽  
Metered Dose ◽  
Flow Through ◽  
Pressurized Metered Dose Inhalers

Pressurized metered-dose inhalers (pMDIs) have been the most effective therapeutic treatment for controlling lung diseases such as asthma and COPD. The flow through a two-orifice system of pMDI is very complex and poorly understood. Previous experimental work has shown that metastability may play a significant role in determining the flow conditions inside pMDIs. In this paper, we present the findings of a homogeneous equilibrium model with those of a delayed equilibrium model (DEM) accounting for propellant metastability. These results are compared with the available experimental and numerical predictions Further, the DEM was applied with HFA propellants R134A and R227, and the results were compared with traditional propellant R12.

Impact of Print Parameters on Pressure Drop in Turbulent Flow Through 3-D Printed Pipes

2020 ◽  
Author(s):  
Thomas G. Shepard ◽  
John Wentz ◽  
Tucker Bender ◽  
Derek Olmschenk ◽  
Alex Gutenberg
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Acrylonitrile Butadiene Styrene ◽  
Industrial Applications ◽  
Relative Pressure ◽  
Fused Filament Fabrication ◽  
Pressure Drops ◽  
Flow Through

Abstract Flow conduits made via additive manufacturing, commonly referred to as 3-D printing, are of increasing interest for a variety of industrial applications due to the ability to create unique and conformal flow paths that would not be possible with other fabrication techniques. Fused filament fabrication (FFF) is an additive manufacturing technique that is seeing new interest in the creation of internal flow channels with its ability to print high-temperature polymers and soluble supports. Printing parameter choices in the FFF printing process result in surfaces that can have significant profile differences that may significantly impact the flow characteristics within the conduits. In this study, two print parameters were experimentally studied for turbulent water flow through circular pipes created by fused filament fabrication out of acrylonitrile butadiene styrene (ABS). The print layer orientation relative to the flow was investigated for printing layers parallel, perpendicular, and at 45 degrees from the flow axis. Layer thickness were varied from 0.254 mm to 0.330 mm and all channels were created using soluble support structures. Pressure drops were measured for fully developed flow through pipes with an inside diameter of 5 mm and Reynolds numbers up to 62,000. Results are presented in terms of relative pressure drops as well as the wall surface roughness that would lead to such impacts. These flow-determined grain surface roughnesses are then compared against measurements of print surface roughness.

Numerical simulation and experiment for study on internal flow pattern of vortex pump

2019 ◽  
Vol 36 (5) ◽  
pp. 1579-1596
Author(s):  
Hui Quan ◽  
Yi Chai ◽  
Rennian Li ◽  
Jianhui Guo
Keyword(s):  
Flow Pattern ◽  
Theoretical Foundation ◽  
Internal Flow ◽  
Content Type ◽  
Vortex Pump ◽  
Hydraulic Design ◽  
Through Flow ◽  
Simulation And Experiment ◽  
Flow Through ◽  
Working Out

Purpose The special structure of the vortex pump contributes to its complex internal flow pattern. A type of horizontal 150WX-200-20 vortex pump is taken as a research subject to deeply study the progression and distribution of flow pattern in its channel. To explain the mechanism of flow in this pump, numerical analysis of the whole flow and experiment have been conducted. Design/methodology/approach The authors studied and analyzed the distribution and evolution of flow pattern under different flow, such as circulating-flow, through-flow and other forms. Finally, a model of flow pattern in the vortex pump has been built, which has more perfectly fit the reality. Findings They are through-flow affected by circulating-flow, main and subsidiary circulating-flow, vortices between vanes and other vortices (or liquid impingement) in volute. Entering the pump, part of the flow stays in vanes and turn into vortices while the other goes into the front chamber. The flow that runs into the front chamber will be divided into two parts. One part will be collected by viscosity into a vortex rope when it passing through the interface between the impeller and the vaneless chamber, which closely relates to the circulating-flow, and the rest directly goes out of the field through the diffuser. Besides, a fraction of circulating-flow joins the through-flow when it goes through the section V and leaves the pump. Originality/value The research results build a theoretical foundation for working out the flow mechanism of the vortex pump, improving its efficiency and optimizing its hydraulic design.

E205 Visualization Study on Interaction of Jet Internal Flow and Surrounding Flow through Interface in Pool

2009 ◽  
Vol 2009.14 (0) ◽  
pp. 431-434
Author(s):  
Yuta UCHIYAMA ◽  
Yutaka ABE ◽  
Akiko KANEKO ◽  
Hideki NARIAI ◽  
Makoto YAMAGISHI ◽  
...  
Keyword(s):  
Internal Flow ◽  
Flow Through

scholarly journals Optimization of a Hydraulic Mixing Nozzle

2008 ◽  
Author(s):  
Joshua J. Engelbrecht ◽  
Douglas S. McCorkle ◽  
Daniel A. Ashlock ◽  
Kenneth M. Bryden
Keyword(s):  
Forced Flow ◽  
Limiting Factors ◽  
Optimized Design ◽  
Nozzle Design ◽  
Cfd Model ◽  
Minimum Power Consumption ◽  
Magnification Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

In industry, mixing tanks are used to homogenize two or more different products that have been combined. This work investigates the use of computational fluid dynamics (CFD) to seek an enhanced design for a hydraulic mixing nozzle. This paper outlines a method for a numerical specification of a nozzle design and generation of a CFD model to analyze it. Characteristics that influence jet distance and trajectory, such as horn size, shape, and entrainment area, are reviewed. The relative importance of each of these traits and which traits have the most significant impact on the quality of a given design are explored. Suggestions for nozzle design are summarized. This information allows the most limiting factors of a tank mixing design to be mitigated to the largest extent possible. Currently industry uses magnification ratio (the ratio of flow out of the nozzle divided by the forced flow through the nozzle jet) for mixing tank nozzle design. This paper illustrates that using magnification ratio or velocity alone does not result in an optimized design. These factors must be weighted to obtain a design that balances these factors to mix the geometry of fluid volume. Additionally, this work shows that nozzle placement is perhaps more significant than nozzle design for optimum mixing with minimum power consumption.

scholarly journals EXPERIMENTAL INVESTIGATION INTO FACTORS AFFECTING THE TRANSIENT FLOW OF FLUID THROUGH AN ORIFICE IN REALISTIC CONDITIONS

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
C D Wood ◽  
D A Hudson ◽  
M Tan ◽  
A J Sobey ◽  
Y Wang
Keyword(s):  
Transient Flow ◽  
Internal Flow ◽  
Environmental Safety ◽  
Empirical Measure ◽  
Factors Affecting ◽  
Hull Girder ◽  
Flooding Event ◽  
Simplified Method ◽  
Flow Through ◽  
Coefficient Of Discharge

During operations, damage can occur with a resulting ingress or egress of fluid. The incoming water affects the reserve buoyancy and it can also change stability and hull girder loading. During a flooding event it is vital that the flow through the damaged orifice and the movement of floodwater around the structure can be predicted quickly to avoid further damage and ensure environmental safety. The empirical measure coefficient of discharge is used as a simplified method to quantify the flooding rate. In many internal flow applications the coefficient of discharge is estimated to be 0.6 but recent research shows that it can vary considerably when applied to transient flooding flows. This paper uses an experimental setup to investigate how changes to the orifice edges and position within the structure affect the flow. It is then used to investigate the coefficient in a more realistic scenario, a static compartment in waves.

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