Latest in physics.flu-dyn

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Contour Dynamics for Surface Quasi-Geostrophic FrontsJul 15 2019We use contour dynamics to derive equations of motion for infinite planar surface quasi-geostrophic (SQG) fronts, and show that it leads to the same result as a regularization procedure introduced previously by Hunter and Shu (2018).
Singularities in Fluid MechanicsJul 15 2019Singularities of the Navier-Stokes equations occur when some derivative of the velocity field is infinite at any point of a field of flow (or, in an evolving flow, becomes infinite at any point within a finite time). Such singularities can be mathematical ... More
Turbulent radial thermal counterflow in the framework of the HVBK modelJul 14 2019We apply the coarse-grained Hall-Vinen-Bekarevich-Khalatnikov (HVBK) equations to model the statistically steady-state, turbulent, cylindrically symmetric radial counterflow generated by a moderately large heat flux from the surface of a cylinder immersed ... More
Self-sustaining process of minimal attached eddies in turbulent channel flowJul 14 2019It has been recently shown that the energy-containing motions in turbulent channel flow exist in the form of Townsend's attached eddies by a numerical experiment which simulates the energy-containing motions only at a prescribed spanwise length scale ... More
Wake Characterisation of 3-Dimensional Multiscale Porous ObstaclesJul 13 2019In this research article we study the wake formation behind 3-Dimensional Multi-scale Porous Obstacles (3DMPOs). Particle Imaging Velocimetry (PIV) is used in a non-shallow ($B/h =1.5$) water flume, with measurements carried out across the $x$ - $y$ plane ... More
Validation of a model for estimating the strength of the vortex created by a Vortex Generator from its Bound CirculationJul 12 2019A hypothesis is tested and validated for predicting the vortex strength induced by a vortex generator in wall-bounded flow by combining the knowledge of the Vortex Generator (VG) geometry and the approaching boundary layer velocity distribution. In this ... More
Residual cross-grid flow numerical error in large-eddy simulations of cumulus-topped boundary layersJul 12 2019A computational domain translation velocity is often used in LES simulations to improve computational performance by allowing longer time-step intervals. Even though the equations of motion are Galilean invariant, LES results have been observed to depend ... More
Modeling and prediction of the peak radiated sound in sub-sonic axisymmetric air jets using acoustic analogy based asymptotic analysisJul 11 2019This paper uses asymptotic analysis within the generalized acoustic analogy formulation (Goldstein. J. Fluid Mech 488, pp. 315-333, 2003) to develop a noise prediction model for the peak sound of axisymmetric round jets at subsonic acoustic Mach numbers ... More
Active Flow Control for Drag Reduction of a Plunging Airfoil under Deep Dynamic StallJul 11 2019High-fidelity simulations are performed to study active flow control techniques for alleviating deep dynamic stall of a SD7003 airfoil in plunging motion. The flow Reynolds number is $Re=60{,}000$ and the freestream Mach number is $M=0.1$. Numerical simulations ... More
Analysis of azimuthal magnetorotational instability and Tayler instability of rotating MHD flows via an extended Hain-Lust equationJul 11 2019Short-wavelength local analysis and numerical global analysis are made of the azimuthal magnetorotational instability of rotating flows of an electrically conducting fluid, subject to an arbitrary but axisymmetric azimuthal magnetic field, to three-dimensional ... More
Optical conductivity in graphene: hydrodynamic regimeJul 11 2019Experimental investigation of hydrodynamics in electron fluids is a highly topical research area that emerged during the last few years. A recent measurement of the optical conductivity in graphene [P. Gallagher, Science 364, 158 (2019)] offers ... More
A DNS Study of entrainment in an axisymmetric turbulent jet as an episodic processJul 11 2019This investigation is based on a DNS of a steady self-preserving incompressible axisymmetric turbulent jet at a Reynolds number of 2400. The DNS data enable accurate maps of the outer irrotational flow field, and also the vorticity field in the turbulent ... More
Heteroclinic and Homoclinic Connections in a Kolmogorov-Like FlowJul 11 2019Recent studies suggest that unstable recurrent solutions of the Navier-Stokes equation provide new insights into dynamics of turbulent flows. In this study, we compute an extensive network of dynamical connections between such solutions in a weakly turbulent ... More
Statistical Measures and Selective Decay Principle for Generalized Euler DynamicsJul 11 2019We investigate the statistical mechanics of a family of two dimensional (2D) fluid flows, described by the generalized Euler equations, or {\alpha}-models. We aim to study the equilibrium mechanics, using initially a point-vortex approximation and then ... More
Turbulence and self-similarity in highly-aerated shear flows: the stable hydraulic jumpJul 11 2019Hydraulic jumps are oftentimes encountered in natural and human-made environments. The transition from supercritical to subcritical flow involves large energy dissipation rates and substantial air entrainment, preventing the use of monophasic flow measurement ... More
A deep learning enabler for non-intrusive reduced order modeling of fluid flowsJul 10 2019In this paper, we introduce a modular deep neural network (DNN) framework for data-driven reduced order modeling of dynamical systems relevant to fluid flows. We propose various deep neural network architectures which numerically predict evolution of ... More
A new basis for filament simulation in three dimensionsJul 10 2019Jul 11 2019Simulations of slender inextensible filaments in a viscous fluid are often plagued by numerical stiffness. Recent coarse-graining studies have reduced the computational requirements of such systems, though have thus far been limited to the motion of planar ... More
A new basis for filament simulation in three dimensionsJul 10 2019Simulations of slender inextensible filaments in a viscous fluid are often plagued by numerical stiffness. Recent coarse-graining studies have reduced the computational requirements of such systems, though have thus far been limited to the motion of planar ... More
Dipolophoresis in concentrated suspensions of ideally polarizable spheresJul 10 2019The dynamics of ideally polarizable spherical particles in concentrated suspensions under the effects of nonlinear electrokinetic phenomena is analysed using large-scale numerical simulations. Particles are assumed to carry no net charge and considered ... More
Retention of rising oil droplets in density stratificationJul 09 2019Following the Deepwater Horizon oil well leak in 2010, approximately 40 percent of the spilled oil remained trapped deep beneath the ocean surface. While it has been demonstrated that these trapped intrusion layers, composed of small oil droplets, are ... More
Forced three-wave interactions of capillary-gravity surface wavesJul 09 2019{Three-wave resonant interactions constitute an essential nonlinear mechanism coupling capillary surface waves. In a previous work, Haudin et al. [Phys. Rev E 93, 043110 (2016)], we have characterized experimentally the generation by this mechanism of ... More
Nonlinear Electrophoresis of Highly Charged Nonpolarizable ParticlesJul 09 2019Nonlinear field dependence of electrophoresis in high fields has been investigated theoretically, yet experimental studies have failed to reach consensus on the effect. In this work, we present a systematic study on the nonlinear electrophoresis of highly ... More
Turbulent flows over dense filament canopiesJul 09 2019Turbulent flows over dense canopies consisting of rigid filaments of small size are investigated using direct numerical simulation. The effect of the height and spacing of the canopy elements on the overlying turbulence is studied. In these dense canopies, ... More
The nanoscale instability driving Leidenfrost film collapseJul 08 2019Above a critical temperature known as the Leidenfrost point (LFP), a heated surface can suspend a liquid droplet above a film of its own vapor. The insulating vapor film can be highly detrimental in metallurgical quenching and thermal control of electronic ... More
Formation of shocks for 2D isentropic compressible EulerJul 08 2019We consider the 2D isentropic compressible Euler equations, with pressure law $p(\rho) = (\sfrac{1}{\gamma}) \rho^\gamma$, with $\gamma >1$. We provide an elementary constructive proof of shock formation from smooth initial datum of finite energy, with ... More
Spot the Difference: Accuracy of Numerical Simulations via the Human Visual SystemJul 08 2019Comparative evaluation lies at the heart of science, and determining the accuracy of a computational method is crucial for evaluating its potential as well as for guiding future efforts. However, metrics that are typically used have inherent shortcomings ... More
The Turbulent DynamoJul 08 2019The generation of magnetic field in an electrically conducting fluid generally involves the complicated nonlinear interaction of flow turbulence, rotation and field. This dynamo process is of great importance in geophysics, planetary science and astrophysics, ... More
Dual channels of helicity cascade in turbulent flowsJul 08 2019Helicity, as one of only two inviscid invariants in three-dimensional turbulence, plays an important role in the generation and evolution of turbulence. From the traditional viewpoint, there exists only one channel of helicity cascade similar to that ... More
Buoyancy-driven exchange flows in inclined ductsJul 08 2019Buoyancy-driven exchange flows arise in the natural and built environment wherever bodies of fluids at different densities are connected by a narrow constriction. In this paper we study these flows in the laboratory using the canonical stratified inclined ... More
Contact line depinning from sharp edgesJul 08 2019With aim of finding mathematical criteria for contact line depinning from sharp corners, we have studied the equilibrium and stability of a semi-infinite planar liquid layer pinned at the vertex of a wedge. Equilibrium is compatible with a fan of apparent ... More
Lagrangian coherent sets in turbulent Rayleigh-Bénard convectionJul 08 2019Coherent circulation rolls and their relevance for the turbulent heat transfer in a two-dimensional Rayleigh--B\'{e}nard convection model are analyzed. The flow is in a closed cell of aspect ratio four at a Rayleigh number ${\rm Ra}=10^6$ and at a Prandtl ... More
Fluid flocks with inertiaJul 08 2019Inertia drives a flocking transition in extensile active suspensions. In a system with mass density $\rho$, viscosity $\mu$, mean active stress $\sigma_0$, characteristic self-propulsion speed $v_0$, Frank elastic constant $K$ and flow-alignment parameter ... More
Single-spectrum prediction of kurtosis of water waves in a non-conservative modelJul 08 2019We study statistical properties after a sudden episode of wind for water waves propagating in one direction. A wave with random initial conditions is propagated using a forced-damped higher order Nonlinear Schr\"odinger equation (NLS). During the wind ... More
Combined measurement of velocity and temperature in liquid metal convectionJul 08 2019Combined measurements of velocity components and temperature in a turbulent Rayleigh-B\'enard convection flow at a low Prandtl number of $\mathit{Pr} = 0.029$ and Rayleigh numbers between $10^6 < \mathit{Ra} < 6 \times 10^7$ are conducted in a series ... More
Simulating convection-coupled phase-change in enthalpy form with mixed finite elementsJul 08 2019Melting and solidification processes are often affected by natural convection of the liquid, posing a multi-physics problem involving fluid flow, convective and diffusive heat transfer, and phase-change reactions. Enthalpy methods formulate this convection-coupled ... More
Viscosity in cosmic fluidsJul 08 2019We consider the fluid description of Dark-matter in the presence of dissipation. In the standard scenario, dark-matter is considered to be cold and collisionless, in the effective fluid description the dissipative effects arise when the nonlinearity is ... More
Knot spectrum of turbulenceJul 08 2019Streamlines, vortex lines and magnetic flux tubes in turbulent fluids and plasmas display a great amount of coiling, twisting and linking, raising the question as to whether their topological complexity (continually created and destroyed by reconnections) ... More
Leveraging viscous peeling in soft actuators and reconfigurable microchannel networksJul 07 2019The research fields of microfluidics and soft robotics both involve complex small-scale internal channel networks, embedded within a solid structure. This work examines leveraging viscous peeling as a mechanism to create and activate soft actuators and ... More
An Initial Attempt of Converged Machine-Learning Assisted Turbulence Modeling in RANS Simulations with Eddy-Viscosity HypothesisJul 06 2019This work presents a converged framework of Machine-Learning Assisted Turbulence Modeling (MLATM). Our objective is to develop a turbulence model directly learning from high fidelity data (DNS/LES) with eddy-viscosity hypothesis induced. First, the target ... More
Lipid Bilayer Hydrodynamic DragJul 05 2019The hydrodynamic drag at a lipid bilayer surface determines in part the flow properties of suspensions of cells and liposomes. Given the fluidity of lipid bilayers, it is not obvious a priori whether solid-like no-slip, liquid-like no-stress, or intermediate ... More
A constrained pressure-temperature residual (CPTR) method for non-isothermal multiphase flow in porous mediaJul 05 2019In petroleum reservoir simulation, the standard preconditioner, the Constrained Pressure Residual (CPR) method, is a two-stage process which involves solving a restricted pressure system. Initially designed for isothermal models, this approach is often ... More
Periodic outgassing as a result of unsteady convection in Ray Lava Lake, Mount Erebus, AntarcticaJul 05 2019Persistently active lava lakes show continuous outgassing and open convection over years to decades. Ray Lake, the lava lake at Mount Erebus, Ross Island, Antarctica, maintains long-term, near steady-state behavior in temperature, heat flux, gas flux, ... More
On Hamiltonian continuum mechanicsJul 04 2019Continuum mechanics can be formulated in the Lagrangian frame (where properties of continuum particles are addressed) or in the Eulerian frame (where fields livein an inertial frame). There is a canonical Hamiltonian structure in the Lagrangian frame. ... More
Heat transfer in rough-wall turbulent thermal convection in the ultimate regimeJul 04 2019Heat and momentum transfer in wall-bounded turbulent flow, coupled with the effects of wall-roughness, is one of the outstanding questions in turbulence research. In the standard Rayleigh-B\'enard problem for natural thermal convection, it is notoriously ... More
Sharp transitions in rotating turbulent convection: Lagrangian acceleration statistics reveal a second critical Rossby numberJul 04 2019In RB convection for fluids with Prandtl number $Pr\gtrsim 1$, rotation beyond a critical (small) rotation rate is known to cause a sudden enhancement of heat transfer which can be explained by a change in the character of the BL dynamics near the top ... More
Helical distributed chaos in magnetic field of solar windJul 04 2019Helical distributed chaos in magnetic field has been studied using results of direct numerical simulations (dominated by magnetic helicity), of a laboratory experiment with plasma wind tunnel and of solar wind measurements (dominated by combined magnetic ... More
Light-Control of Localised Photo-Bio-ConvectionJul 04 2019Microorganismal motility is often characterised by complex responses to environmental physico-chemical stimuli. Although the biological basis of these responses is often not well understood, their exploitation already promises novel avenues to directly ... More
Subcritical asymmetric Rayleigh breakup of a charged drop in an AC quadrupole trapJul 04 2019In a first of its kind high-speed imaging of breakup of a charged drop, we unambiguously demonstrate Rayleigh fission of a charged droplet. Specifically, we demonstrate using experiments and numerical calculations that an isolated charged drop, levitated ... More
Particles in turbulent separated flow over a bump: effect of the Stokes number and lift forceJul 04 2019Particle-laden turbulent flow that separates due to a bump inside a channel is simulated to analyse the effects of the Stokes number and the lift force on the particle spatial distribution. The fluid friction Reynolds number is approximately 900 over ... More
Mass transport for Pollard wavesJul 03 2019We provide an in-depth exploration of the mass-transport properties of Pollard's exact solution for a zonally-propagating surface water-wave in infinite depth. Without resorting to approximations we discuss the Eulerian mass transport of this fully nonlinear, ... More
Boltzmann distribution of sediment transportJul 03 2019The coupling of sediment transport with the flow that drives it allows rivers to shape their own bed. Cross-stream fluxes of sediment play a crucial, yet poorly understood, role in this process. Here, we track particles in a laboratory flume to relate ... More
Optimal spanwise-periodic control for recirculation length in a backward-facing step flowJul 03 2019Three-dimensional control is considered in the flow past a backward-facing step (BFS). The BFS flow at Reynolds number $Re=500$ (defined with the step height and the maximum inlet velocity) is two-dimensional and linearly stable but increasingly receptive ... More
Control-oriented model reduction for minimizing transient energy growth in shear flowsJul 02 2019A linear non-modal mechanism for transient amplification of perturbation energy is known to trigger sub-critical transition to turbulence in many shear flows. Feedback control strategies for minimizing this transient energy growth can be formulated as ... More
Some preliminary observations on a defect Navier-Stokes systemJul 02 2019Some implications of the simplest accounting of defects of compatibility in the velocity field on the structure of the classical Navier-Stokes equations are explored, leading to connections between classical elasticity, the elastic theory of defects, ... More
Experimental Evidence of Hydrodynamic Instantons: The Universal Route to Rogue WavesJul 02 2019A statistical theory of rogue waves is proposed and tested against experimental data collected in a long water tank where random waves with different degrees of nonlinearity are mechanically generated and free to propagate along the flume. Strong evidence ... More
The onset of thermo-compositional convection in rotating spherical shellsJul 02 2019Double-diffusive convection driven by both thermal and compositional buoyancy in a rotating spherical shell can exhibit a rather large number of behaviours often distinct from that of the single diffusive system. In order to understand how the differences ... More
Numerical modelling of shock-bubble interactions using a pressure-based algorithm without Riemann solversJul 02 2019Jul 03 2019The interaction of a shock wave with a bubble features in many engineering and emerging technological applications, and has been used widely to test new numerical methods for compressible interfacial flows. Recently, density-based algorithms with pressure-correction ... More
How do trapped particles interact with and sample superfluid vortex excitations?Jul 02 2019Particles have been used for more than a decade to visualize and study the dynamics of quantum vortices in superfluid helium. In this work we study how the dynamics of a collection of particles set inside a vortex reflects the motion of the vortex. We ... More
Variable thrust and high efficiency propulsion with oscillating foils at high Reynolds numbersJul 01 2019Bio-inspired oscillatory foil propulsion has the ability to traverse various propulsive modes by dynamically changing the foil's heave and pitch kinematics. This research characterizes the propulsion properties of a symmetric oscillating foil at a high ... More
Swimming eukaryotic microorganisms exhibit a universal speed distributionJul 01 2019One approach to quantifying biological diversity consists of characterizing the statistical distribution of specific properties of a taxonomic group or habitat. Microorganisms living in fluid environments, and for whom motility is key, exploit propulsion ... More
A volume-of-fluid method for interface-resolved simulations of phase-changing two-fluid flowsJul 01 2019We present a numerical method for interface-resolved simulations of evaporating two-fluid flows based on the volume-of-fluid (VoF) method. The method has been implemented in an efficient FFT-based two-fluid Navier-Stokes solver, using an algebraic VoF ... More
A Light-Driven Microgel RotorJul 01 2019The current understanding of motility through body shape deformation of microorganisms and the knowledge of fluid flows at the microscale provides ample examples for mimicry and design of soft microrobots. In this work, a two-dimensional spiral is presented ... More
Nonlinear theory of magnetohydrodynamic flows of stratified rotating plasma in two-layer shallow water approximation. Rossby waves and their three-wave interactionsJul 01 2019This article deals with rotating magnetohydrodynamic flows of a thin stratified layer of astrophysical plasma in a gravitational field with a free-surface in a vertical external magnetic field. Magnetohydrodynamic equations are obtained in the two-layer ... More
Direct Measurement of the Elastohydrodynamic Lift Force at the NanoscaleJul 01 2019Friction in soft and wet contacts is crucial for industry and engineering, but it might also play a central role for the motion of various physiological and biological entities, as well as for the nanorheology of very soft materials. Here, we report on ... More
Discrete effect on the anti-bounce-back boundary condition of lattice Bhatnagar-Gross-Krook model for convection-diffusion equationsJul 01 2019The discrete effect on the boundary condition has been a fundamental topic for the lattice Boltzmann method in simulating heat and mass transfer problems. In previous works based on the halfway anti-bounce-back (ABB) boundary condition for convection-diffusion ... More
Determination of energy flux rate in homogeneous ferrohydrodynamic turbulence using two-point statisticsJul 01 2019In ferrofluids the suspended ferromagnetic particles agglomerate due to the interaction between the particle magnetic moment and the external magnetic field, which in turn, influences the turbulence and relaxation time. The relaxation time becomes large ... More
Translation and rotation of a spherical particle in a turbulent boundary layerJul 01 2019Three-dimensional particle tracking experiments were conducted in a turbulent boundary layer with friction Reynolds number $Re_\tau$ of 700 and 1300. Two finite size spheres with specific gravities of 1.003 (P1) and 1.050 (P2) and diameters of 60 and ... More
Deformation and sorting of capsules in a T-junctionJun 30 2019We study experimentally the motion and deformation of individual capsules transported by a constant volume-flux flow of low Reynolds number, through the T-junction of a channel with rectangular cross-section. We use millimetric ovalbumin-alginate capsules ... More
Consolidation of freshly deposited cohesive and non-cohesive sediment: particle-resolved simulationsJun 30 2019We analyze the consolidation of freshly deposited cohesive and non-cohesive sediment by means of particle-resolved direct Navier-Stokes simulations based on the Immersed Boundary Method. The computational model is parameterized by material properties ... More
Electrokinetics Enhances Cross-stream Particle Migration in Viscoelastic FlowsJun 29 2019Advancements in understanding the lateral migration of particles have helped in enhanced separation in microfluidic devices. In this work, we investigate the effects of electrokinetics on the particle migration in a viscoelastic flow, where the electric ... More
Spontaneous critical layer formation and robustness beneath rotational wavesJun 28 2019Non-stationary rotational surface waves are considered, where the underlying current has constant vorticity. A study is presented on the robustness of a critical layer in the presence of a bottom topography, as well as on its spontaneous formation for ... More
Kinetic and internal energy transfer in forced compressible turbulenceJun 28 2019We revisit the problem of how energy transfer through the turbulent cascade operates in compressible hydrodynamic turbulence. In general, there is no conservative compressible cascade since the kinetic and internal energy reservoirs can exchange energy ... More
Dynamics of groups of magnetically driven artificial microswimmersJun 28 2019Magnetically driven artificial microswimmers have the potential to revolutionize many biomedical technologies, such as minimally-invasive microsurgery, micro-particle manipulation, and localized drug delivery. However, many of these applications will ... More
Third-order structure functions for isotropic turbulence with bidirectional energy transferJun 27 2019We derive and test a new heuristic theory for third-order structure functions that resolve the forcing scale in the scenario of simultaneous spectral energy transfer to both small and large scales, which can occur naturally in rotating stratified turbulence ... More
The Charged FENE-P Dumbbell model: explaining the rheology of dilute polyelectrolyte solutionsJun 27 2019A robust model of dilute polyelectrolyte solutions is constructed based on kinetic theory arguments. The polyelectrolyte molecules are modelled by finitely elongated non-linear elastic dumbbells with beads carrying identical effective charges. The electric ... More
Disorder suppresses chaos in viscoelastic flowsJun 27 2019Jul 11 2019Viscoelastic flows transition from steady to time-dependent, chaotic dynamics under critical flow conditions, but the implications of geometric disorder for flow stability in these systems are unknown. Utilizing microfluidics, we flow a viscoelastic fluid ... More
Disorder suppresses chaos in viscoelastic flowsJun 27 2019Viscoelastic flows transition from steady to time-dependent, chaotic dynamics under critical flow conditions, but the implications of geometric disorder for flow stability in these systems are unknown. Utilizing microfluidics, we flow a viscoelastic fluid ... More
On the Maxwell-Stefan diffusion limit for a reactive mixture of polyatomic gases in non-isothermal settingJun 27 2019In this article we deduce a mathematical model of Maxwell-Stefan type for a reactive mixture of polyatomic gases with a continuous structure of internal energy. The equations of the model are derived in the diffusive limit of a kinetic system of Boltzmann ... More
Reduced-Order Quasilinear Model of Ocean Boundary-Layer TurbulenceJun 27 2019The combined effectiveness of model reduction and the quasilinear approximation for the reproduction of the low-order statistics of oceanic surface boundary-layer turbulence is investigated. Idealized horizontally homogeneous problems of surface-forced ... More
Orbital Bifurcations and Shoaling of Cnoidal WavesJun 27 2019We study the parameter space of cnoidal waves -- the periodic solitons of the Korteweg-de Vries equation -- from the perspective of Virasoro coadjoint orbits. The monodromy method familiar from inverse scattering implies that many, but not all, of these ... More
-8/3 spectrum in kinetic Alfvén wave turbulence: implications for the solar windJun 27 2019The nature of solar wind turbulence at large scale is rather well understood in the theoretical framework of magnetohydrodynamics. The situation is quite different at sub-proton scales where the magnetic energy spectrum measured by different spacecrafts ... More
On the prediction of critical heat flux using a physics-informed machine learning-aided frameworkJun 26 2019The critical heat flux (CHF) corresponding to the departure from nucleate boiling (DNB) crisis is essential to the design and safety of a two-phase flow boiling system. Despite the abundance of predictive tools available to the thermal engineering community, ... More
Swimmers' wakes are not reliable indicators of swimming performanceJun 26 2019The structure of swimmers' wakes is often assumed to be an indicator of swimming performance. Here, we discuss three cases where this assumption fails. In general, great care should be taken in deriving any conclusions about swimming performance from ... More
Vascular journey and adhesion mechanics of micro-sized carriers in narrow capillariesJun 25 2019Micro and nano-particles are systemically injected as drug carriers to specifically deliver therapeutics into diseased tissue. Their vascular journey and adhesion mechanics are key ingredient to optimize strategies mainly against cancer and cardiovascular ... More
Injection of Deformable Capsules in a Reservoir, a Systematic AnalysisJun 25 2019A computational study of capsule ejection from a narrow channel into a reservoir is undertaken for a combination of varying deformable capsule sizes and channel dimensions. A mass spring membrane model is coupled to an Immersed Boundary Lattice Boltzmann ... More
On the intrinsic three-dimensionality of the flow normal to a circular diskJun 25 2019Direct numerical simulations are performed for the steady flow normal to a circular disk at the Reynolds number of 1000. Numerical simulations are conducted with different levels of simplification procedure by reducing the azimuthal extension of the disk. ... More
Singularity formation as a wetting mechanism in a dispersionless water wave modelJun 25 2019The behavior of a class of solutions of the shallow water Airy system originating from initial data with discontinuous derivatives is considered. Initial data are obtained by splicing together self-similar parabolae with a constant background state. These ... More
Viscous fingering in fractured porous mediaJun 25 2019The effect of heterogeneities induced by highly permeable fracture networks on viscous miscible fingering in porous media is examined using high-resolution numerical simulations. We consider the planar injection of a less viscous fluid into a two-dimensional ... More
Direct numerical simulations of atomization of a liquid jet in a swirling gas crossflowJun 25 2019Breakup of a liquid jet in a high speed gaseous crossflow finds wide range of engineering and technological applications, especially in the combustors of the gas turbine engines in aerospace industry. In this study, we present volume-of-fluid method based ... More
Clustering of floating tracers in weakly divergent velocity fieldsJun 25 2019This work focuses on buoyant tracers floating on the ocean surface and treats the geostrophic and ageostrophic surface velocities as the 2D solenoidal (non-divergent) and potential (divergent) flow components, respectively. We consider a random kinematic ... More
Experimental and Numerical Investigation of Corona Discharge Induced Flow on a Flat PlateJun 24 2019Electrohydrodynamic (EHD) flow induced by planar corona discharge in the wall boundary layer region is investigated experimentally and via a multiphysics computational model. The EHD phenomena has many potential engineering applications, its optimization ... More
Non-local model for surface tension in fluid-fluid simulationsJun 24 2019We propose a non-local model for surface tension obtained in the form of an integral of a molecular-force-like function with support $3.5\varepsilon$ added to the Navier-Stokes momentum conservation equation. We demonstrate analytically and numerically ... More
Effective drag of a rod in fluid-saturated granular bedsJun 24 2019We measure the drag encountered by a vertically oriented rod moving across a sedimented granular bed immersed in a fluid under steady-state conditions. At low rod speeds, the presence of the fluid leads to a lower drag because of buoyancy, whereas a significantly ... More
Generation of a large-scale vorticity in a fast rotating density stratified turbulence or turbulent convectionJun 24 2019We find an instability resulting in generation of large-scale vorticity in a fast rotating density stratified small-scale turbulence or turbulent convection. In a simplest case when the angular velocity is along gravity (the vertical direction), the large-scale ... More
Role of the sonic scale in the growth of magnetic field in compressible turbulenceJun 24 2019We study the growth of small fluctuations of magnetic field in supersonic turbulence, the small-scale dynamo. The growth is due to the fastest turbulent eddies above the resistive scale. We observe that for supersonic turbulence these eddies are effectively ... More
Non-uniform electro-osmotic flow drives fluid-structure instabilityJun 24 2019We demonstrate the existence of a fluid-structure instability arising from the interaction of electro-osmotic flow with an elastic substrate. Considering the case of flow within a soft fluidic chamber, we show that above a certain electric field threshold, ... More
A non-intrusive reduced order modeling framework for quasi-geostrophic turbulenceJun 24 2019In this study, we present a non-intrusive reduced order modeling (ROM) framework for large-scale quasi-stationary systems. The framework proposed herein exploits the time series prediction capability of long short-term memory (LSTM) recurrent neural network ... More
Vortex Simulations on a 3-SphereJun 23 2019We generate vortex tangles using a Hopf flow on a 3-sphere, in place of the standard torus defined by periodic boundary conditions. These tangles are highly anisotropic, with vortices tending to align along the flow direction. Standard power law dependences ... More
Automated Droplet Size Distribution Measurements Using Digital Inline HolographyJun 23 2019Droplet generation through spray breakup is an unsteady and non-linear process which produces a relatively dense, highly polydisperse aerosol containing non-spherical droplets with sizes spanning several orders of magnitude. Such variability in size and ... More
Electrophoresis of active Janus particlesJun 23 2019We theoretically consider the dynamics of a self-propelled active Janus motor moving in an external electric field. The external field can manipulate the route of a Janus particle and enforce it to move towards the desired targets. To investigate the ... More