Fluids

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Special Issue Editor

Dr. Amir Riaz

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Guest Editor

Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
Interests: numerical methods for multiphase flow; multiscale modeling and simulation of multiphase flow in porous media, microchannels and heat exchangers; multiphase transport of mixtures in porous media; perturbation analysis of interfacial instability; carbon dioxide sequestration; enhanced oil recovery; boiling in low gravity

Special Issue Information

Dear Colleagues,

Modeling and simulation of the coupled multiphase motion of immiscible fluids and the associated thermal transport is of fundamental importance in the study of a wide range of physical processes occurring in nature and engineered processes. Multiphase flow is important for the mixing of reactants in combustion and for the dispersion of pollutants in the atmosphere and the oceans. It plays an important role in the thermal packaging of electronics, in the thermal management of nuclear reactors, as well as the diagnosis and prevention of disease in biological systems.

Despite enjoying a long history of activity due to its central importance in nature and engineering applications, modeling and simulation of multiphase flow continues to receive wide attention due to the substantial challenges associated with the accuracy, efficiency, and robustness of simulation techniques as well as the modeling of physics related to the interfacial transport of mass, momentum, and energy. Over the years, numerous methods and approaches have evolved to address myriad aspects of these challenges.

This Special Issue aims to report novel numerical methods and new physical phenomena related to multiphase flow as well as provide an overview of recent developments, progress, and implementation of these methods in diverse applications, including bubbly flow, spray atomization, drop formation, viscoelastic solids, and thermal transport processes involving nucleate, film, and flow boiling processes.

Dr. Amir Riaz
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fluids is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

multiphase flow
numerical simulation
phase change
nucleate boiling
flow boiling
viscoelastic solid
fluid solid interaction
dynamic contact line
interfacial jump conditions
instability

Published Papers (2 papers)

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Research

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18 pages, 3814 KiB

Open AccessArticle

An Explicit Analytical Solution for Transient Two-Phase Flow in Inclined Fluid Transmission Lines

by Taoufik Wassar, Matthew A. Franchek, Hamdi Mnasri and Yingjie Tang

Fluids 2021, 6(9), 300; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids6090300 - 24 Aug 2021

Viewed by 2015

Abstract

Due to the complex nonlinearity characteristics, analytical modeling of compressible flow in inclined transmission lines remains a challenge. This paper proposes an analytical model for one-dimensional flow of a two-phase gas-liquid fluid in inclined transmission lines. The proposed model is comprised of a steady-state two-phase flow mechanistic model in-series with a dynamic single-phase flow model. The two-phase mechanistic model captures the steady-state pressure drop and liquid holdup properties of the gas-liquid fluid. The developed dynamic single-phase flow model is an analytical model comprised of rational polynomial transfer functions that are explicitly functions of fluid properties, line geometry, and inclination angle. The accuracy of the fluid resonant frequencies predicted by the transient flow model is precise and not a function of transmission line spatial discretization. Therefore, model complexity is solely a function of the number of desired modes. The dynamic single-phase model is applicable for under-damped and over-damped systems, laminar, and turbulent flow conditions. The accuracy of the overall two-phase flow model is investigated using the commercial multiphase flow dynamic code OLGA. The mean absolute error between the two models in step response overshoot and settling time is less than 8% and 2 s, respectively. Full article

(This article belongs to the Special Issue Numerical Methods and Physical Aspects of Multiphase Flow)

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Review

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48 pages, 8203 KiB

Open AccessEditor’s ChoiceReview

An Overview of the Lagrangian Dispersion Modeling of Heavy Particles in Homogeneous Isotropic Turbulence and Considerations on Related LES Simulations

by Daniel G. F. Huilier

Fluids 2021, 6(4), 145; https://0-doi-org.brum.beds.ac.uk/10.3390/fluids6040145 - 08 Apr 2021

Cited by 11 | Viewed by 3457

Abstract

Particle tracking is a competitive technique widely used in two-phase flows and best suited to simulate the dispersion of heavy particles in the atmosphere. Most Lagrangian models in the statistical approach to turbulence are based either on the eddy interaction model (EIM) and the Monte-Carlo method or on random walk models (RWMs) making use of Markov chains and a Langevin equation. In the present work, both discontinuous and continuous random walk techniques are used to model the dispersion of heavy spherical particles in homogeneous isotropic stationary turbulence (HIST). Their efficiency to predict particle long time dispersion, mean-square velocity and Lagrangian integral time scales are discussed. Computation results with zero and no-zero mean drift velocity are reported; they are intended to quantify the inertia, gravity, crossing-trajectory and continuity effects controlling the dispersion. The calculations concern dense monodisperse spheres in air, the particle Stokes number ranging from 0.007 to 4. Due to the weaknesses of such models, a more sophisticated matrix method will also be explored, able to simulate the true fluid turbulence experienced by the particle for long time dispersion studies. Computer evolution and performance since allowed to develop, instead of Reynold-Averaged Navier-Stokes (RANS)-based studies, large eddy simulation (LES) and direct numerical simulation (DNS) of turbulence coupled to Generalized Langevin Models. A short review on the progress of the Lagrangian simulations based on large eddy simulation (LES) will therefore be provided too, highlighting preferential concentration. The theoretical framework for the fluid time correlation functions along the heavy particle path is that suggested by Wang and Stock. Full article

(This article belongs to the Special Issue Numerical Methods and Physical Aspects of Multiphase Flow)

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