Recent Advances in Computational Methods in Fluid Dynamics and Applications

A special issue of Fluids (ISSN 2311-5521). This special issue belongs to the section "Mathematical and Computational Fluid Mechanics".

Deadline for manuscript submissions: closed (31 July 2021) | Viewed by 28444

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Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA
Interests: computational fluid dynamics (CFD); computational magnetohydrodynamics (MHD); electromagnetics; computational aeroacoustics; multidisciplinary design and optimization; rarefied gas dynamics and hypersonic flows, bio-fluid dynamics; flow and flight control
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Special Issue Information

Dear Colleagues,

With nearly five decades of development, there have been tremendous advancements in the basic building blocks of computational fluid dynamics (CFD), namely, geometry modeling and mesh generation, numerical algorithms for the solution of fluid dynamics equations, and turbulence modeling. A large number of proprietary and commercial CFD codes have been developed that are now routinely used in all industrial applications involving fluid flow. Nevertheless, new advances continue to emerge in all building blocks of CFD. In this Special Issue, papers are invited from researchers on higher-order spatial and temporal numerical schemes, entropy stable schemes, gas-kinetic schemes, algorithms for overset meshes and adaptive meshes, parallel algorithms, analysis of algorithms, uncertainty quantifications, verification and validation, large data and machine learning algorithms, and other advanced topics. Papers are also invited on wall-modeled and wall-resolved methods for DES, LES, and DNS, as well as new turbulence models for RANS. Papers on large-scale CFD computations using advanced algorithms are especially welcome.

Prof. Dr. Ramesh K. Agarwal
Guest Editor

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Keywords

  • computational fluid dynamics
  • geometry modeling
  • mesh generation
  • numerical algorithms
  • fluid dynamics equations

Published Papers (10 papers)

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Research

31 pages, 1922 KiB  
Article
Influence of Particle Mass Fraction over the Turbulent Behaviour of an Incompressible Particle-Laden Flow
by Carlos Alberto Duque-Daza, Jesus Ramirez-Pastran and Santiago Lain
Fluids 2021, 6(11), 374; https://doi.org/10.3390/fluids6110374 - 21 Oct 2021
Cited by 4 | Viewed by 1644
Abstract
The presence of spherical solid particles immersed in an incompressible turbulent flow was numerically investigated from the perspective of the particle mass fraction (PMF or ϕm), a measure of the particle-to-fluid mass ratio. Although a number of different changes have been [...] Read more.
The presence of spherical solid particles immersed in an incompressible turbulent flow was numerically investigated from the perspective of the particle mass fraction (PMF or ϕm), a measure of the particle-to-fluid mass ratio. Although a number of different changes have been reported to be obtained by the presence of solid particles in incompressible turbulent flows, the present study reports the findings of varying ϕm in the the turbulent behaviour of the flow, including aspects such as: turbulent statistics, skin-friction coefficient, and the general dynamics of a particle-laden flow. For this purpose, a particle-laden turbulent channel flow transporting solid particles at three different friction Reynolds numbers, namely Reτ=180, 365, and 950, with a fixed particle volume fraction of ϕv=103, was employed as conceptual flow model and simulated using large eddy simulations. The value adopted for ϕv allowed the use of a two-way coupling approach between the particles and the flow or carrier phase. Three different values of ϕm were explored in this work ϕm1,2.96, and 12.4. Assessment of the effect of ϕm was performed by examining changes of mean velocity profiles, velocity fluctuation profiles, and a number of other relevant turbulence statistics. Our results show that attenuation of turbulence activity of the carrier phase is attained, and that such attenuation increases with ϕm at fixed Reynolds numbers and ϕv. For the smallest Reynolds number case considered, flows carrying particles with higher ϕm exhibited lower energy requirements to sustain constant fluid mass flow rate conditions. By examining the flow velocity field, as well as instantaneous velocity components contours, it is shown that the attenuation acts even on the largest scales of the flow dynamics, and not only at the smaller levels. These findings reinforce the concept of a selective stabilising effect induced by the solid particles, particularly enhanced by high values of ϕm, which could eventually be exploited for improvement of energetic efficiency of piping or equivalent particles transport systems. Full article
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29 pages, 3036 KiB  
Article
Semi-Implicit Finite Volume Procedure for Compositional Subsurface Flow Simulation in Highly Anisotropic Porous Media
by Sebastián Echavarría-Montaña, Steven Velásquez, Nicolás Bueno, Juan David Valencia, Hillmert Alexander Solano and Juan Manuel Mejía
Fluids 2021, 6(10), 341; https://doi.org/10.3390/fluids6100341 - 28 Sep 2021
Cited by 2 | Viewed by 2321
Abstract
Subsurface multiphase flow in porous media simulation is extensively used in many disciplines. Large meshes with non-orthogonalities (e.g., corner point geometries) and full tensor highly anisotropy ratios are usually required for subsurface flow applications. Nonetheless, simulations using two-point flux approximations (TPFA) fail to [...] Read more.
Subsurface multiphase flow in porous media simulation is extensively used in many disciplines. Large meshes with non-orthogonalities (e.g., corner point geometries) and full tensor highly anisotropy ratios are usually required for subsurface flow applications. Nonetheless, simulations using two-point flux approximations (TPFA) fail to accurately calculate fluxes in these types of meshes. Several simulators account for non-orthogonal meshes, but their discretization method is usually non-conservative. In this work, we propose a semi-implicit procedure for general compositional flow simulation in highly anisotropic porous media as an extension of TPFA. This procedure accounts for non-orthogonalities by adding corrections to residual in the Newton-Raphson method. Our semi-implicit formulation poses the guideline for FlowTraM (Flow and Transport Modeller) implementation for research and industry subsurface purposes. We validated FlowTraM with a non-orthogonal variation of the Third SPE Comparative Solution Project case. Our model is used to successfully simulating a real Colombian oil field. Full article
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6 pages, 258 KiB  
Article
A Note on Stokes Approximations to Leray Solutions of the Incompressible Navier–Stokes Equations in ℝn
by Joyce C. Rigelo, Janaína P. Zingano and Paulo R. Zingano
Fluids 2021, 6(10), 340; https://doi.org/10.3390/fluids6100340 - 27 Sep 2021
Viewed by 1536
Abstract
In the early 1980s it was well established that Leray solutions of the unforced Navier–Stokes equations in Rn decay in energy norm for large t. With the works of T. Miyakawa, M. Schonbek and others it is now known that the [...] Read more.
In the early 1980s it was well established that Leray solutions of the unforced Navier–Stokes equations in Rn decay in energy norm for large t. With the works of T. Miyakawa, M. Schonbek and others it is now known that the energy decay rate cannot in general be any faster than t(n+2)/4 and is typically much slower. In contrast, we show in this note that, given an arbitrary Leray solution u(·,t), the difference of any two Stokes approximations to the Navier–Stokes flow u(·,t) will always decay at least as fast as t(n+2)/4, no matter how slow the decay of u(·,t)L2(Rn) might be. Full article
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15 pages, 1329 KiB  
Article
Bio-Mechanical and Bio-Rheological Aspects of Sickle Red Cells in Microcirculation: A Mathematical Modelling Approach
by Purnima Chaturvedi, Rohit Kumar and Sapna Ratan Shah
Fluids 2021, 6(9), 322; https://doi.org/10.3390/fluids6090322 - 8 Sep 2021
Cited by 1 | Viewed by 1803
Abstract
Sickle cell disease (SCD) is an inherited monogenic disease characterized by distorted red blood cells that causes vaso-occlusion and vasculopathy. Presently, electrophoresis of haemoglobin and genotyping are used as routine tests for diagnosis of the SCD. These techniques require specialized laboratories and are [...] Read more.
Sickle cell disease (SCD) is an inherited monogenic disease characterized by distorted red blood cells that causes vaso-occlusion and vasculopathy. Presently, electrophoresis of haemoglobin and genotyping are used as routine tests for diagnosis of the SCD. These techniques require specialized laboratories and are expensive. The low-cost microfluidics-based diagnostic tool holds a great attention for screening of red blood cell (RBC) deformability. In the present study, lubrication theory has been applied in order to develop a biomechanical model of microcirculation with altered rheological properties of sickle blood in the capillary, which is smaller in size compared to the cell diameter, to explain the multifactorial nature and pathogenesis of vaso-occlusion in SCD. The governing equations have been solved analytically for realistic boundary conditions and simulated using MATLAB. We found that the axial velocity of the cell decreases with a decrease in deformability and compliance. The height of the lubricating film predicts deformation of the cell with respect to local pressure in the microcirculation. Leak back and drag force depend non-linearly on the deformed cell radius with varying viscosity of the plasma and Reynolds number. The modelling predictions of this study is in coherence with experimental results. The analyzed parameters provide unique insights with novel possibilities to design a microfluidics-based effective therapeutic intervention for SCD. Full article
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13 pages, 4850 KiB  
Article
Computational Fluid Dynamics Study of the Hydrodynamic Characteristics of a Torpedo-Shaped Underwater Glider
by Thanh-Long Le and Duc-Thong Hong
Fluids 2021, 6(7), 252; https://doi.org/10.3390/fluids6070252 - 11 Jul 2021
Cited by 9 | Viewed by 4490
Abstract
In this study, numerical computation is used to investigate the hydrodynamic characteristics of a torpedo-shaped underwater glider. The physical model of a torpedo-shaped underwater glider is developed by Myring profile equations and analyzed by the computational fluid dynamics approach. The Navier–Stokes equations and [...] Read more.
In this study, numerical computation is used to investigate the hydrodynamic characteristics of a torpedo-shaped underwater glider. The physical model of a torpedo-shaped underwater glider is developed by Myring profile equations and analyzed by the computational fluid dynamics approach. The Navier–Stokes equations and the energy equation coupled with the appropriate boundary conditions are solved numerically by using Comsol Multiphysics software. The numerical results contribute to the major part of reducing the effects of fluid flow on the glider’s profile and make the underwater glider more hydrodynamically efficient. The drag and lift forces acting on the underwater glider are enhanced by a higher velocity and a larger angle of attack of the underwater glider. Since the obtained results show a good observation with the experimental works, the need and the practicality of using CFD in the glider design process are proven. Full article
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29 pages, 8939 KiB  
Article
Classical and Multisymplectic Schemes for Linearized KdV Equation: Numerical Results and Dispersion Analysis
by Adebayo Abiodun Aderogba and Appanah Rao Appadu
Fluids 2021, 6(6), 214; https://doi.org/10.3390/fluids6060214 - 8 Jun 2021
Cited by 6 | Viewed by 1853
Abstract
We construct three finite difference methods to solve a linearized Korteweg–de-Vries (KdV) equation with advective and dispersive terms and specified initial and boundary conditions. Two numerical experiments are considered; case 1 is when the coefficient of advection is greater than the coefficient of [...] Read more.
We construct three finite difference methods to solve a linearized Korteweg–de-Vries (KdV) equation with advective and dispersive terms and specified initial and boundary conditions. Two numerical experiments are considered; case 1 is when the coefficient of advection is greater than the coefficient of dispersion, while case 2 is when the coefficient of dispersion is greater than the coefficient of advection. The three finite difference methods constructed include classical, multisymplectic and a modified explicit scheme. We obtain the stability region and study the consistency and dispersion properties of the various finite difference methods for the two cases. This is one of the rare papers that analyse dispersive properties of methods for dispersive partial differential equations. The performance of the schemes are gauged over short and long propagation times. Absolute and relative errors are computed at a given time at the spatial nodes used. Full article
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16 pages, 359 KiB  
Article
On Solving the Nonlinear Falkner–Skan Boundary-Value Problem: A Review
by Asai Asaithambi
Fluids 2021, 6(4), 153; https://doi.org/10.3390/fluids6040153 - 9 Apr 2021
Cited by 4 | Viewed by 2644
Abstract
This article is a review of ongoing research on analytical, numerical, and mixed methods for the solution of the third-order nonlinear Falkner–Skan boundary-value problem, which models the non-dimensional velocity distribution in the laminar boundary layer. Full article
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21 pages, 10484 KiB  
Article
Effects of Mesh Generation on Modelling Aluminium Anode Baking Furnaces
by Jose Libreros and Maria Trujillo
Fluids 2021, 6(4), 140; https://doi.org/10.3390/fluids6040140 - 4 Apr 2021
Cited by 2 | Viewed by 2292
Abstract
Anode baking is critical in carbon anode production for aluminium extraction. Operational and geometrical parameters have a direct impact on the performance of anode baking furnaces (ABF), and hence on the resulting anode quality. Gas flow patterns, velocity field, pressure drop, shear stress [...] Read more.
Anode baking is critical in carbon anode production for aluminium extraction. Operational and geometrical parameters have a direct impact on the performance of anode baking furnaces (ABF), and hence on the resulting anode quality. Gas flow patterns, velocity field, pressure drop, shear stress and turbulent dissipation rate are the main operational parameters to be optimised, considering a specific geometry that is discretised as a mesh. Therefore, this paper aims to establish the need to generate an appropriate mesh to perform accurate numerical simulations of three-dimensional turbulent flow in a single section of an ABF. Two geometries are considered for generating three meshes, using COMSOL and cfMesh, with different refinement zones. The three meshes are used for creating nine incompressible isothermal turbulent flow models, with varying operational parameters. Velocity field, convergence and turbulent viscosity ratio in the outlet of fuel inlet pipes are the quantification criteria. Quantification criteria have shown that a better physical representation is obtained by refining in the whole combustion zone. COMSOL Multiphysics’ built-in mesh generator allows quadrilateral, tetrahedron and hexahedron shapes. Adaptive cell sizes and shapes have a place within modelling, since refining a mesh in appropriate zones brings the Peclet number down when the incompressible isothermal turbulent flow is simulated. Full article
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16 pages, 95290 KiB  
Article
CFD and Experimental Study of Wind Pressure Distribution on the High-Rise Building in the Shape of an Equilateral Acute Triangle
by Norbert Jendzelovsky and Roland Antal
Fluids 2021, 6(2), 81; https://doi.org/10.3390/fluids6020081 - 12 Feb 2021
Cited by 7 | Viewed by 4708
Abstract
There is a lack of detailed information about wind flow and distribution of wind pressure around atypically shaped high-rise buildings. The national standard EN 1991-1-4 Eurocode 1 used to determine the effects of wind on the territory of Slovakia (and indeed other countries [...] Read more.
There is a lack of detailed information about wind flow and distribution of wind pressure around atypically shaped high-rise buildings. The national standard EN 1991-1-4 Eurocode 1 used to determine the effects of wind on the territory of Slovakia (and indeed other countries of the European Union) does not have a procedure for determining the effects of wind on objects of triangular shape. This presents a problem for designers and engineers, as there exist no generally binding/valid rules to follow when performing the wind effect analysis. This paper shows the procedure of identification and results of the external wind pressure coefficient for the triangularly shaped high-rise building. Two methods of calculation have been chosen for this purpose. First, experimental measurements were performed on a scaled model of the building cross-section in the wind tunnel. Subsequently, software simulations were performed on the same scaled model in the CFD (computational fluid dynamics) program ANSYS CFX. Results of wind pressure were obtained for two directions of wind flow measured in 16 sampling points distributed irregularly around the circumference of the model. Results were mutually compared and verified. At the end, the wind flow effects on a real-size triangular high-rise building in the built-up area performed by software simulation are shown. Full article
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21 pages, 8964 KiB  
Article
Effects of Inflow Condition on RANS and LES Predictions of the Flow around a High-Rise Building
by Giulio Vita, Simone Salvadori, Daniela Anna Misul and Hassan Hemida
Fluids 2020, 5(4), 233; https://doi.org/10.3390/fluids5040233 - 7 Dec 2020
Cited by 11 | Viewed by 3335
Abstract
An increasing number of engineering applications require accurate predictions of the flow around buildings to guarantee performance and safety. This paper investigates the effects of variations in the turbulent inflow, as predicted in different numerical simulations, on the flow pattern prediction around buildings, [...] Read more.
An increasing number of engineering applications require accurate predictions of the flow around buildings to guarantee performance and safety. This paper investigates the effects of variations in the turbulent inflow, as predicted in different numerical simulations, on the flow pattern prediction around buildings, compared to wind tunnel tests. Turbulence characteristics were assessed at several locations around a model square high-rise building, namely, above the roof region, at the pedestrian level, and in the wake. Both Reynolds-averaged Navier–Stokes (RANS, where turbulence is fully modelled) equations and large-eddy simulation (LES, where turbulence is partially resolved) were used to model an experimental setup providing validation for the roof region. The performances of both techniques were compared in ability to predict the flow features. It was found that RANS provides reliable results in regions of the flow heavily influenced by the building model, and it is unreliable where the flow is influenced by ambient conditions. In contrast, LES is generally reliable, provided that a suitable turbulent inflow is included in the simulation. RANS also benefits when a turbulent inflow is provided in simulations. In general, LES should be the methodology of choice if engineering applications are involved with the highly separated and turbulent flow features around the building, and RANS provides reliable information when regions of high wind speed and low turbulence are investigated. Full article
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