Science topic

# Fluid Mechanics - Science topic

Fluid mechanics is the study of fluids and the forces on them. Fluid mechanics can be divided into fluid statics, the study of fluids at rest; fluid kinematics, the study of fluids in motion; and fluid dynamics, the study of the effect of forces on fluid motion.

Publications related to Fluid Mechanics (10,000)

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Recent investigations on the liquids and lattices are both active. In this paper, with symbolic computation, we consider a (3+1)-dimensional generalized Yu-Toda-Sasa-Fukuyama system for the interfacial waves in a two-layer liquid or elastic waves in a lattice, with two sets of the bilinear auto-Bäcklund transformations hereby built up. Moreover, we...

The two papers in the title contain some equations that are not complete. The missing terms, which are of topological origin, were recently unveiled by Björn Gustafsson. In this note, we present the equations of Gustafsson in the case of a single vortex in a compact boundaryless surface, and show that many conclusions we have reached with the incom...

Heat is a branch of thermodynamics that occupies a unique position due to its involvement in the field of practice. Being linked to the management, transport and exchange of energy in thermal form, it impacts all aspects of human life and activity.
Heat transfers are, by nature, classified as conduction, convection (which inserts conduction into fl...

Burgers-type equations are seen in cosmology, hydrodynamics, plasma physics, hurricane dynamics, statistical dynamics, traffic modelling, etc. For an extended (2+1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlengt...

We consider in this paper multiphase flow models involving two, three or four fields, in total mechanical and thermodynamical disequilibrium. Thus several pressure fields arise, and we precisely focus here on the pressure relaxation process, while restricting to four distinct multiphase flow models. The first two models only involve immiscible comp...

A wide variety of stationary or moving spatially localized structures is present in evolution problems on unbounded domains, governed by higher-than-second-order reversible spatial interactions. This work provides a generic unfolding in one spatial dimension of a certain codimension-three singularity that explains the organization of bifurcation di...

This book, Theory of Gyroscopic Fields, presents a new description of two types of movement already known in physics, such as rotation and precession of objects and which, according to the theory presented here, experience in a unified way, that is, that is, according to the same mathematical model, both solid and fluid bodies.
Said unification is...

Pool fires are canonical representations of many accidental fires, which can exhibit an unstable unsteady behaviour, known as puffing, which involves a strong coupling between the temperature and velocity fields. Despite their practical relevance to fire research, their experimental study can be limited due to the complexity of measuring relevant q...

Physics-informed neural networks (PINNs) can be used to solve partial differential equations (PDEs) and identify hidden variables by incorporating the governing equations into neural network training. In this study, we apply PINNs to the assimilation of mean flow data and investigate the method's ability to identify inaccessible variables and closu...

The generation of ocean surface waves by wind is a classic fluid mechanics problem whose theoretical study dates back to 1957, when the two seminal papers by Phillips and Miles were published in the incipient Journal of Fluid Mechanics. Comprehensively understanding the mechanism of wind-wave generation is of crucial importance to many naval applic...

Our presentation keeps a historical line of reasoning, since we start from old concepts of fluid mechanics and finish on concepts of modern field theory. We want to show that some facts from the nature phenomena, which have firstly been discovered on the ground of fluid mechanics, were next incorporated into physics and later become the important p...

We obtain sharp rotation bounds for the subclass of homeomorphisms $$f:{\mathbb {C}}\rightarrow {\mathbb {C}}$$ f : C → C of finite distortion which have distortion function in $$L^p_{loc}$$ L loc p , $$p>1$$ p > 1 , and for which a Hölder continuous inverse is available. The interest in this class is partially motivated by examples arising from fl...

We study the long-time behaviour of axisymmetric solutions without swirl for the three-dimensional Navier-Stokes equations in the whole space. Assuming that the initial vorticity is sufficiently localised, we compute explicitly the leading terms in the asymptotic expansion of the solution, both for the vorticity and the velocity field. In particula...

With the premise that N-soliton solutions are acquired, this paper will focus on the nonlinear superposition between one lump and other types of localised waves of the (2+1)-dimensional generalized Caudrey-Dodd-Gibbon-Kotera-Sawada(gCDGKS) equation. By introducing a novel constraint, combining the long wave limit method and mode resonance method, i...

The prediction of global optima for non-convex and expensive objective functions is a pervasive challenge across many engineering applications and research areas. Bayesian optimization (BO) is a powerful method for solving optimization problems of this type, as it replaces the expensive search space of the objective function with a less expensive G...

In this paper the numerical simulation of the interaction between viscoelastic fluid flows and hyperelastic solids is approached. The algorithm employed is a classical block-iterative scheme, in which the solid and the fluid mechanics problems are solved sequentially. A Galerkin finite element approach has been employed for the numerical approximat...

Wavelets methods are commonly used for the numerical solution of partial differential equations. In this paper, we extend the Legendre wavelet polynomial of one variable to Legendre wavelet polynomial of two variables to approximate the solution of fractional partial differential equations. Convergence analysis for the solution is discussed. Total...

Water inrush of collapse column in the coal seam floor in the karst area is a frequent hydrogeological disaster, and it is becoming one of the significant hidden dangers threatening the safety of coal mine production in China. Based on the self-developed variable mass seepage test system of broken rock mass, different Talbot gradation seepage tests...

We investigate the statistics of rogue waves occurring in the inverse cascade of surface gravity wave turbulence. In such statistically homogeneous, stationary and isotropic wave fields, low-frequency waves are generated by nonlinear interactions rather than directly forced by a wave maker. This provides a laboratory realization of arguably the sim...

In this paper we construct a large class of non-trivial (non-radial) self-similar solutions of the generalized surface quasi-geostrophic equation (gSQG). To the best of our knowledge, this is the first rigorous construction of any self-similar solution for these equations. The solutions are of spiral type, locally integrable, and may have mixed sig...

Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical analysis and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-...

Biosensors are ubiquitous in a variety of disciplines, such as biochemical, electrochemical, agricultural, and biomedical areas. They can integrate various point-of-care applications, such as in the food, healthcare, environmental monitoring, water quality, forensics, drug development, and biological domains. Multiple strategies have been employed...

The dynamic response of structural elements subjected to blast loading is a problem of growing interest in the field of defense and security. In this work, a novel computational tool for the rapid evaluation of the effects of explosions, hereafter referred as SimEx, is presented and discussed. The classical correlations for the reference chemical (...

In the domain of aeronautical industry, the risk of lightning strike is taken into account from the conception of the aircrafts as the phenomenon statistically occurs every 1000 to 10000 flight hours. As this phenomenon involves a lightning channel that is static in the terrestrial reference frame and an aircraft that can reach a speed of 100 m/s i...

Background and aim:
This study evaluates the upper airway flow characteristics, anatomical features and analyzes their correlations with AHI in patients with varied degrees of OSA severity seeking for discernments of the underlying pathophysiological profile.
Materials and methods:
Patient-specific computational fluid dynamics models were recons...

Lab-on-PCB (LoP) has been the subject of increasing research. These devices emerge as an evolution of “lab on a chip” and “PCB-MEMS”. They share interesting properties with lab-on-chip devices, for example, rapid response time and small fluid volume. In addition, lab-on-PCB devices are interesting due to the integration of electronics, sensors, act...

In big thermal power plants, mixed flow pumps are commonly utilized for cooling water operations. In mixed flow pump impeller design, meridional streamlines are estimated by dividing the annulus by equal area. Inlet and output blade angles are determined empirically based on speed. Before estimating meridional streamlines, similar coefficients are...

Despite rapid advances in the field of organic solar cells (OSCs), high‐performance large‐scale OSC modules are limited. In this study, it is found that the non‐Newtonian fluid feature of conjugated polymer primarily causes the wedge‐shaped mass (donor and/or acceptor component)/phase distribution of blends in large‐scale blade coating, which resul...

This paper aims to study the path oscillations of single, spherical water droplets levitated in a wind tunnel to better comprehend the mechanical motion of small raindrops. The observations were carried out in the Mainz vertical wind tunnel. The discrete, fast Fourier transform was used to determine the oscillatory frequencies of the droplet paths,...

We present a pragmatic view of self-similarity, which is indeed rooted in refined mathematical theory and unravelling in multiple approximations , hypotheses, and working approaches, all aimed at solving differential problems by extracting the essence of the results. In developing self-similar solutions, the main concern of the scientist is not the...

We show that the (symmetry-reduced) gravitational sectors describing i) the flat FRLW cosmology filled with a massless scalar field and ii) the Schwarzschild black hole mechanics both admit the two dimensional centrally extended Schrödinger group as a dynamical symmetry, a symmetry shared by the compressible Navier-Stokes equation. To this end, we...

We show that the (symmetry-reduced) gravitational sectors describing i) the flat FRLW cosmology filled with a massless scalar field and ii) the Schwarzschild black hole mechanics both admit the two dimensional centrally extended Schr\"{o}dinger group as a dynamical symmetry, a symmetry shared by the compressible Navier-Stokes equation. To this end,...

The identification of the correct thermodynamic states forming in supercritical mixing and combustion is an important area of research in engineering. When a multi-component mixture evolves at pressures that are higher than the critical pressures of each individual component, a real-gas (RG) equation of state (EoS) must be used in order to achieve...

The techniques in functional analysis have widespread applications in the modeling of numerous natural phenomena. As such, these techniques and tools are multidisciplinary in nature and indispensable in the study of natural sciences. Fixed-point theory, fractional calculus, partial differential equations, integral equations, wavelet analysis, and a...

This study extends the input-output framework for the receptivity analysis of an incompressible boundary layer introduced by Ran et al. [Phys. Rev. Fluids 4, 093901 (2019)] to the laminar adiabatic supersonic case. Spatially distributed in the wall-normal direction, a δ-correlated Gaussian noise is considered as input, both including the velocity a...

Unexploded ordnance devices (UXO) pose a potential threat to human life and material during offshore construction activities. Extensive survey activities are conducted to locate, identify, and clear these objects as necessary. For the period thereafter, it is necessary to investigate whether areas that have already been cleared, or even objects tha...

Practice shows that CO2/N2-ECBM is an effective technology to enhance coalbed methane. However, there are few field tests in which the technology is applied to enhance the gas drainage in underground coal mines, and the effect is uncertain. In this study, firstly, the reasons for the decrease of gas drainage efficiency in the exhaustion period were...

Even though both fluid mechanics and numerical studies have considerably progressed in the past decades, experimental knowledge remains an important tool for studying the resistance to flow in fluid media where a complex environment dominates the flow pattern. After a comprehensive review of the recent literature on the drag coefficient in open cha...

The acceleration and heating of particles in gas-particle flows represents a general question in fluid mechanics and has been widely studied since the 1920s. However, studies on the gas adsorption-desorption process of a particle in a gas-particle flow are still lacking. In this paper, we aim to introduce a framework with which to explain the gas a...

Standard neural networks can approximate general nonlinear operators, represented either explicitly by a combination of mathematical operators, e.g., in an advection-diffusion-reaction partial differential equation, or simply as a black box, e.g., a system-of-systems. The first neural operator was the Deep Operator Network (DeepONet), proposed in 2...

Natural materials are highly organized into intricate and sophisticated hierarchical structures from which superior properties emerge. In the wake of biomimicry, there is a growing interest in designing architected materials in the laboratory as such structures could enable myriad functionalities in engineering. Yet, their fabrication remains chall...

Using a Cauchy integral formulation of the boundary integral equations, we simulate the erosion a porous medium comprised of up to 100 solid bodies embedded in a Stokes flow. The grains of the medium are resolved individually and erode under the action of surface shear stress. Through nonlinear feedback with the surrounding flow fields, microscopic...

This book is new version as of July 5, 2022. This book was downloaded over 10 million times in the last 10 year. For this version new the open channel flow chapter and several examples of the fish locomotion. 831 pages with many breakthroughs packed with many examples.

A swarm of volcano-tectonic earthquakes (VTEs) started in May 2018 at the east of Mayotte. In addition, in the following month, long-period earthquakes (LPEs) also started occurring at this swarm zone, transmitting long-period (LP) waves whose records in broadband seismographs are analyzed. Since then, 251 LPEs of magnitude (Ms) between 3.2 and 4.9...

This paper describes a numerical investigation of the characteristics of supercavitating flow using hot gas. The numerical results are validated through an experimental study under the same conditions at Chungnam National University Cavitation Tunnel. The temperature gradient, velocity profile, and pressure distribution inside the supercavity are i...

We introduce a data-driven approach to the modelling and analysis of viscous fluid mechanics. Instead of including constitutive laws for the fluid's viscosity in the mathematical model, we suggest to directly use experimental data. Only a set of differential constraints, derived from first principles, and boundary conditions are kept of the classic...

Cubic catalysts are very crucial in the fluid mechanics due to the chemical processes boosted with less energy. Cubic catalysts in the chemical process have numerous applications in the chemical engineering and food industry, like transformation or storage of different types of food materials, turning raw materials into useful products and accelera...

EU Academy of Sciences
Universal Journal of Fluid Mechanics 10 (2022)

A leading two-dimensional aerodynamics representation analysis is further improved and investigated for the determination of inviscid flowfields of unsteady airfoils. Thus, the above problem of the unsteady flow of a two-dimensional NACA airfoil is reduced to the solution of a non-linear multidimensional singular integral equation, when the form of...

In this paper, a generalized mixed nonlinear Schrödinger equation, which arises in several physical applications including fluid mechanics (for the weakly nonlinear dispersive water waves), quantum field theory and nonlinear optics, is investigated. An N-fold generalized Darboux transformation (GDT) is constructed, where N is a positive integer. Ba...

Noise emitted from a rotor due to its interaction with ingested turbulence is dominant for modern submarine propulsors. An experimental study of broadband thrust from a couple of representative pumpjet configurations is conducted in this work. The associated loading noise is further predicted by incorporating the Ffowcs Williams-Hawkings acoustic a...

Background: The relationship between maxillary sinus pneumatization and respiratory-induced fluid mechanics remains unclear. The purpose of this study was to simulate and measure the respiratory-induced mechanical stimulation at the sinus floor under different respiratory conditions and to investigate its potential effect on the elevated sinus foll...

Key Points
An analytical solution in terms of dimensionless fluid‐mechanical circulation versus dimensionless time is for the first time provided in the literature for the modeling of river meander cyclic growth and death and the prediction of the related characteristic times and parameters. The proposed theoretical model hinges on the potential fl...

Computational fluid dynamics (CFD) is a field of fluid mechanics that employs numerical evaluation and interpretation of statistical structures to examine and determine solutions to issues involving fluid flow. Computer systems are programmed to make calculations suited for simulating the free flow of fluids, as well as the interaction of fluids wi...

Resonancia y mecánica de fluidos en el cuerpo humano Pedro Hugo García Peláez Reservados todos los derechos. No se permite la reproducción total o parcial de esta obra, ni su incorporación a un sistema informático, ni su transmisión en cualquier forma o por cualquier medio (electrónico, mecánico, fotocopia, grabación u otros) sin autorización previ...

In cooking, food gels such as agar-agar or alginate are often prepared and presented in the form of spheres or spaghetti. While experimenting in our kitchen, we realized that it is quite difficult to make more advanced shapes. In this study, we sought to develop new methods to obtain more complex shapes. Our first challenge was to obtain helices. T...

The flow of non-Newtonian fluids is extremely important in a variety of industrial applications and processes, including painting, printing, and coating. The goal of this paper is to develop a mathematical model for an incompressible, non-isothermal third-grade fluid as it travels through a minor gap between two heated rolls that are revolving in t...

The flow of non-Newtonian fluids is extremely important in a variety of industrial applications and processes, including painting, printing, and coating. The goal of this paper is to develop a mathematical model for an incompressible, non-isothermal third-grade fluid as it travels through a minor gap between two heated rolls that are revolving in t...

We present a publicly accessible database designed to aid in the conception, training, demonstration, evaluation, and comparison of reduced-complexity models for fluid mechanics. Availability of high-quality flow data is essential for all of these aspects of model development for both data-driven and physics-based methods. The database contains tim...

Multiphysics is a computational discipline which treats simulations that involve multiple physical models or multiple simultaneous physical phenomena. For example, combining chemical kinetics and fluid mechanics or combining finite elements with molecular dynamics. Multiphysics typically involves solving Coupled Systems of partial differential equa...

Poster to be presented at The 1st Spanish Fluid Mechanics Conference (SFMC)

We consider the iterative solution of large linear systems of equations in which the coefficient matrix is the sum of two terms, a sparse matrix $A$ and a possibly dense, rank deficient matrix of the form $\gamma UU^T$, where $\gamma > 0$ is a parameter which in some applications may be taken to be 1. The matrix $A$ itself can be singular, but we a...

We identify incompressible planar linear flows that are generalizations of the well known one-parameter family characterized by the ratio of in-plane extension to (out-of-plane) vorticity. The latter `canonical' family is classified into elliptic and hyperbolic linear flows with closed and open streamlines, respectively, corresponding to the extens...

Navier–Stokes (NS) equation, in fluid mechanics, is a partial differential equation that
describes the flow of incompressible fluids. We study the fractional derivative by using fractional
differential equation by using a mild solution. In this work, anomaly diffusion in fractal media
is simulated using the Navier–Stokes equations (NSEs) with time-...