MATHEMATICAL MODELING OF ACOUSTIC IMPACT ON GAS FLOW  IN  VORTEX-ACOUSTIC DISPERSANT

ABSTRACTRecent studies on aluminum degassing [1, 2] show that although the impeller speed and the gas flow rate are important process variables in terms of the productivity and operational costs, the impeller design is also a key design parameter influencing the productivity and the quality of the aluminum in foundry shops. In this work, an improved design of an impeller is tested through a water physical model and mathematical modeling and its performance is compared against commercial designs of impellers. A full-scale water physical model of a batch aluminum degassing unit was used to test the impellers by using the same operating conditions (580 rpm and 40 liters per minute) and by performing deoxidation from water by purging nitrogen into the water saturated with oxygen (similar to the dehydrogenation). A mathematical model based on first principles of mass and momentum conservation equations was developed and solved numerically in the commercial CFD code ANSYS Fluent to describe the hydrodynamics of the system with the objective of explaining the deoxidation kinetics observed in the experiments. It has been found that the new impeller design shows a better performance than the commercial designs in terms of degassing kinetics for the conditions used in this study, which is explained since the new design promotes a flow dynamics that increases the pumping effect, creating a bigger pressure drop and fluid flow patterns which help to drag and distribute more evenly the bubbles in the entire ladle than the commercial designs.

Download Full-text

Mathematical Modeling of Impingement of an Air Jet in a Liquid Bath

MRS Proceedings ◽

10.1557/proc-1276-2 ◽

2010 ◽

Vol 1276 ◽

Author(s):

J. Solórzano-López ◽

R. Zenit ◽

M. A. Ramírez-Argáez

Keyword(s):

Mathematical Modeling ◽

Mathematical Model ◽

Free Surface ◽

Gas Flow ◽

Two Phase ◽

Arc Furnaces ◽

Air Jet ◽

Image Velocimetry ◽

Oxygen Gas ◽

The Mathematical Model

AbstractPhysical and mathematical modeling of jet-bath interactions in electric arc furnaces represent valuable tools to obtain a better fundamental understanding of oxygen gas injection into the furnace. In this work, a 3D mathematical model is developed based on the two phase approach called Volume of Fluid (VOF), which is able to predict free surface deformations and it is coded in the commercial fluid dynamics software FLUENTTM. Validation of the mathematical model is achieved by measurements on a transparent water physical model. Measurements of free surface depressions through a high velocity camera and velocity patterns are recorded through a Particle Image Velocimetry (PIV) Technique. Flow patterns and depression geometry are identified and characterized as function of process parameters like distance from nozzle to bath, gas flow rate and impingement angle of the gas jet into the bath. A reasonable agreement is found between simulated and experimental results.

Download Full-text

Mathematical Modeling of Gas Flow including Heat Transfer in Spiral Heat Exchanger

Transactions of the VŠB - Technical University of Ostrava Mechanical Series ◽

10.22223/tr.2011-2/1866 ◽

2011 ◽

Vol 57 (2) ◽

pp. 7-14

Author(s):

Marian Bojko ◽

Radim Kocich ◽

Adéla Macháčková ◽

Zuzana Klečková

Keyword(s):

Mathematical Modeling ◽

Heat Transfer ◽

Heat Exchanger ◽

Gas Flow ◽

Spiral Heat Exchanger

Download Full-text

Mathematical Modeling Of Radio-Frequency Electromagnetic And Acoustic Impact On Formation In Combination With Solvent Injection

Siberian Journal of Physics ◽

10.54362/1818-7919-2015-10-3-89-96 ◽

2015 ◽

Vol 10 (3) ◽

pp. 89-96

Author(s):

Gulnara Izmaylova ◽

Liana Kovaleva ◽

Nur Nasyrov

Keyword(s):

Mathematical Modeling ◽

Mathematical Model ◽

Radio Frequency ◽

Acoustic Field ◽

High Viscosity ◽

Oil Reservoir ◽

Rf Heating ◽

Low Viscosity ◽

Acoustic Impact ◽

High Viscosity Oil

We investigate the possibility of increasing the efficiency of extraction of high-viscosity oil combined effect of radio-frequency (RF) electromagnetic (EM) and acoustic fields on the formation and miscible displacement oil solvent. A mathematical model of two-stage impact on the oil reservoir. At the 1st stage, the heating of the formation RF electromagnetic and acoustic field. At the 2nd stage the RF heating of the formation with simultaneous injection of low-viscosity solvent.

Download Full-text

Mathematical Modeling of Growth Conditions and Interpretation of Phase Diagram for InxGa1-xN Epitaxial Layer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.372.70 ◽

2013 ◽

Vol 372 ◽

pp. 70-74 ◽

Cited By ~ 2

Author(s):

Md. Soyaeb Hasan ◽

Apurba Kumar Saha ◽

Md. Rafiqul Islam ◽

Nowshad Amin

Keyword(s):

Mathematical Modeling ◽

Phase Diagram ◽

Gas Flow ◽

Epitaxial Film ◽

Growth Parameters ◽

Growth Conditions ◽

Indium Content ◽

Molar Ratio ◽

Organic Vapor ◽

Metal Organic

It is imperative to determine the dependence of the quality and characteristics of the epitaxial film on different growth parameters. A mathematical model has been developed showing the effect of different growth parameters e.g. temperature, TMI and TEG flow rate, molar ratio on epitaxial film. This model is considered for InGaN film on GaN template with an Indium mole fraction up to 0.4 by Metal Organic Vapor Phase Epitaxy (MOVPE). The results obtained from this model has been compared and fitted with experimentally obtained data through XRD, RSM, PL, SEM etc. Finally, a phase diagram has been proposed to interpret the phase separation and Indium content evolution under the influence of growth temperature and precursor gas flow.

Download Full-text

MATHEMATICAL MODELING OF A SUPERSONIC TWIN JET INTERACTION WITH AN OBSTACLE

Vestnik Tomskogo gosudarstvennogo universiteta Matematika i mekhanika ◽

10.17223/19988621/68/7 ◽

2020 ◽

pp. 72-79

Author(s):

Kagenov A.M. ◽

◽

Kostyushin K.V. ◽

Aligasanova K.L. ◽

Kotonogov V.A. ◽

...

Keyword(s):

Mathematical Modeling ◽

Gas Flow ◽

Stokes Equations ◽

Mathematical Formulation ◽

Wave Structure ◽

Stationary Regime ◽

Ideal Gas ◽

Godunov Method ◽

Force Action ◽

Jet Interaction

The paper presents the results of the mathematical modeling of a supersonic twin jet interaction with an obstacle for the Mach number of 4.5 specified at the nozzle exit. Mathematical formulation of the problem includes a system of Favre-averaged Navier-Stokes equations and SST turbulence model for a viscous compressible ideal gas. The calculations are carried out using the free software OpenFOAM Extended with the Godunov method employed. The effect of the distance between nozzles on the shock-wave structure of the gas flow and on the force action of the plumes on the obstacle is studied. The distance between the nozzles varied in the range of 0.1−4. It is found that with an increase in the distance from 0.1 to 0.5, the flow structure is significantly rearranged, and two pressure maxima arise, which increase in comparison to the distance of 0.2. A decrease in pressure on the obstacle is observed at the distance over 1.0. For a distance of 4, two pressure maxima occur on the axis of each jet, while the force action of each jet is half as high as the resultant jet force action for a distance of 0.1. The transition from a stationary regime to a self-oscillating one is observed when the distance exceeds the value of 1.5.

Download Full-text

Physical and Mathematical Modeling of the Interaction of Water Droplets and High-Speed Gas Flow

Applied Sciences ◽

10.3390/app112311146 ◽

2021 ◽

Vol 11 (23) ◽

pp. 11146

Author(s):

Aleksandr Minko ◽

Oleg Guskov ◽

Konstantin Arefyev ◽

Andrey Saveliev

Keyword(s):

Mathematical Modeling ◽

High Speed ◽

Gas Flow ◽

Reynolds Numbers ◽

Droplet Breakup ◽

Flow Conditions ◽

Two Phase ◽

Gas Dynamic ◽

Physical And Mathematical Modeling ◽

Mach Numbers

Present work is devoted to physical and mathematical modeling of the secondary disintegration of a liquid jet and gas-dynamic breakup of droplets in high-speed air flows. In this work the analysis of the experiments of water droplet breakup in the supersonic flow with Mach numbers up to M = 3 was carried out. The influence of shock wave presence in the flow on the intensity of droplets gas-dynamic breakup is shown. A developed empirical model is presented. It allows to predict the distribution of droplet diameters and velocities depending on the gas flow conditions, as well as the physical properties of the liquid. The effect of the Weber and Reynolds numbers on the rate of droplets gas-dynamic breakup at various Mach numbers is shown. The obtained data can be useful in the development of mathematical models for the numerical simulation of two-phase flows in the combined Lagrange-Euler formulation.

Download Full-text