Physics Commons^™

Analysis Of Capillary Flow In Interior Corners : Perturbed Power Law Similarity Solutions, Joshua Thomas Mccraney

Dissertations and Theses

The design of fluid management systems requires accurate models for fluid transport. In the low gravity environment of space, gravity no longer dominates fluid displacement; instead capillary forces often govern flow. This thesis considers the redistribution of fluid along an interior corner. Following a rapid reduction of gravity, fluid advances along the corner measured by the column length z = L(t), which is governed by a nonlinear partial differential equation with dynamical boundary conditions. Three flow types are examined: capillary rise, spreading drop, and tapered corner. The spreading drop regime is shown to exhibit column length growth L ~ …

Developing And Testing An Anguilliform Robot Swimming With Theoretically High Hydrodynamic Efficiency, John B. Potts Iii

University of New Orleans Theses and Dissertations

An anguilliform swimming robot replicating an idealized motion is a complex marine vehicle necessitating both a theoretical and experimental analysis to completely understand its propulsion characteristics. The ideal anguilliform motion within is theorized to produce ``wakeless'' swimming (Vorus, 2011), a reactive swimming technique that produces thrust by accelerations of the added mass in the vicinity of the body. The net circulation for the unsteady motion is theorized to be eliminated.

The robot was designed to replicate the desired, theoretical motion by applying control theory methods. Independent joint control was used due to hardware limitations. The fluid velocity vectors in the …

Approximate Solutions For The Flow And Heat Transfer Due To A Stretching Sheet Embedded In A Porous Medium With Variable Thickness, Variable Thermal Conductivity And Thermal Radiation Using Laguerre Collocation Method, M. M. Khader, Ahmed M. Megahed

Applications and Applied Mathematics: An International Journal (AAM)

In this article, a numerical approach is given for studying the flow of a Newtonian fluid over an impermeable stretching sheet embedded in a porous medium with a power law surface velocity and variable thickness in the presence of thermal radiation. The flow is caused by a non-linear stretching of a sheet. Thermal conductivity of the fluid is assumed to vary linearly with temperature. The governing PDEs are transformed into a system of coupled non-linear ODEs which are using appropriate boundary conditions for various physical parameters. The proposed method is based on replacement of the unknown function by truncated series …

Laminar Boundary Layer Flow Of Sisko Fluid, Manisha Patel, Jayshri Patel, M. G. Timol

Applications and Applied Mathematics: An International Journal (AAM)

The problem of steady two dimensional laminar boundary layer flow of non-Newtonian fluid is analyzed in the present paper. Sisko fluid model, one of the various fluid models of non- Newtonian fluid, is considered for stress-strain relationship. Similarity and numerical solutions obtained for the defined flow problem.

Thermal Instability In A Horizontal Layer Of Walter’S (Model B') Visco-Elastic Nanofluid- A More Realistic Approach, Ramesh Chand, G. C. Rana

Applications and Applied Mathematics: An International Journal (AAM)

Thermal instability in a horizontal layer of Walter’s (Model B') visco-elastic nanofluid is investigated for more realistic boundary conditions. The flux of volume fraction of nanoparticles is taken to be zero on the isothermal boundaries. The model used for nanofluid incorporates the effect of Brownian diffusion and thermophoresis. Perturbation method, normal mode technique and Galerkin method are used in the solution of the eigenvalue problem. Oscillatory convection has been ruled out for the problem under consideration. The influences of the Lewis number, modified diffusivity ratio and nanoparticle Rayleigh number on the stationary convection are shown both analytically and graphically.

Hydromagnetic Flow And Heat Transfer Of Eyring-Powell Fluid Over An Oscillatory Stretching Sheet With Thermal Radiation, S. U. Khan, N. Ali

Applications and Applied Mathematics: An International Journal (AAM)

An analysis is carried out to investigate the magnetohydrodynamic flow and heat transfer in an unsteady flow of Eyring-Powell fluid over an oscillatory stretching surface. The radiation effects are also considered in energy equation. The flow is induced due to infinite elastic sheet which is stretched periodically back and forth in its own plane. Finite difference scheme is used to solve dimensionless partial differential equations. The effects of emerging parameters on both velocity and temperature profiles are illustrated through graphs. The results obtained by means of finite difference scheme are compared with earlier studies and found in excellent agreement.

Boundary-Layer Flow Of Nanofluids Over A Moving Surface In The Presence Of Thermal Radiation, Viscous Dissipation And Chemical Reaction, Eshetu Haile, B. Shankar

Applications and Applied Mathematics: An International Journal (AAM)

The flow problem presented in the paper is boundary-layer flow of nanofluids over a moving surface in the presence of thermal radiation, viscous dissipation and chemical reaction. The plate is assumed to move in the same or opposite direction to the free stream which depends on the sign of the velocity parameter. The partial differential equations appearing in the governing equations are transformed into a couple of nonlinear ordinary differential equations using similarity transformations. The transformed equations in turn are solved numerically by the shooting method along with the fourth order Runge-Kutta integration technique. Influences of the pertinent parameters in …

Viscous Fluid In A Horizontally Rotating Cylinder, Kolter Bradshaw, Zach Van Engen

Student Work

If you race a hoop and a disk of equal mass and radius by rolling them down a ramp, the disk will reach the bottom first due to the difference in how the mass is distributed. For rolling solid objects, this phenomenon is straightforward to model. However, if you roll a hollow cylinder filled with fluid, the situation is more complex due to the way fluid properties, such as viscosity, effect rotation. We are analyzing the motion of fluids and beads in a cylinder in order to observe viscosity effects on the fluid-cylinder system. By examining a rolling fluid-cylinder system …

Distributions Of Long-Lived Radioactive Nuclei Provided By Star-Forming Environments, Marco Fatuzzo, Fred Adams

Faculty Scholarship

Radioactive nuclei play an important role in planetary evolution by providing an internal heat source, which affects planetary structure and helps facilitate plate tectonics. A minimum level of nuclear activity is thought to be necessary—but not sufficient—for planets to be habitable. Extending previous work that focused on short-lived nuclei, this paper considers the delivery of long-lived radioactive nuclei to circumstellar disks in star forming regions. Although the long-lived nuclear species are always present, their abundances can be enhanced through multiple mechanisms. Most stars form in embedded cluster environments, so that disks can be enriched directly by intercepting ejecta from supernovae …

A High-Speed X-Ray Detector System For Noninvasive Fluid Flow Measurements, Timothy B. Morgan, Benjamin R. Halls, Terrence R. Meyer, Theodore J. Heindel

Terrence R Meyer

The opaque nature of many multiphase flows has long posed a significant challenge to the visualization and measurement of desired characteristics. To overcome this difficulty, X-ray imaging, both in the form of radiography and computed tomography, has been used successfully to quantify various multiphase flow phenomena. However, the relatively low temporal resolution of typical X-ray systems limit their use to moderately slow flows and time-average values. This paper discusses the development of an X-ray detection system capable of high-speed radiographic imaging that can be used to visualize multiphase flows. Details of the hardware will be given and then applied to …

Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei

Electronic Thesis and Dissertation Repository

One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is …

Topographic Signatures Of Geodynamics, Samuel G. Roy

Electronic Theses and Dissertations

The surface of the Earth retains an imperfect memory of the diverse geodynamic, climatic, and surface transport processes that cooperatively drive the evolution of Earth. In this thesis I explore the potential of using topographic analysis and landscape evolution models to unlock past and/or present evidence for geodynamic activity. I explore the potential isolated effects of geodynamics on landscape evolution, particularly focusing on two byproducts of tectonic strain: rock displacement and damage. Field evidence supports a strong correlation between rock damage and erodibility, and a numerical sensitivity analysis supports the hypothesis that an order of magnitude weakening in rock, well …

Numerical Solutions Of Generalized Burgers' Equations For Some Incompressible Non-Newtonian Fluids, Yupeng Shu

University of New Orleans Theses and Dissertations

The author presents some generalized Burgers' equations for incompressible and isothermal flow of viscous non-Newtonian fluids based on the Cross model, the Carreau model, and the Power-Law model and some simple assumptions on the flows. The author numerically solves the traveling wave equations for the Cross model, the Carreau model, the Power-Law model by using industrial data. The author proves existence and uniqueness of solutions to the traveling wave equations of each of the three models. The author also provides numerical estimates of the shock thickness as well as maximum strain $\varepsilon_{11}$ for each of the fluids.

Dsmc Simulation Of Microstructure Actuation By Knudsen Thermal Force, Aaron Pikus, Israel Sebastiao, Andrew Strongrich, Alina Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

In many industrial and research applications there is a need for vacuum sensors with higher accuracy and spatial resolution than what is currently available. Examples of target applications include high-altitude platforms, satellites and in-vacuum manufacturing processes such as freeze-drying of food and pharmaceuticals. In this connection, a novel pressure sensor, named Microelectromechanical In-plane Knudsen Radiometric Actuator (MIKRA), has been developed by at Purdue University. MIKRA is based on Knudsen thermal forces generated by rarefied flow driven by thermal gradients within the microstructure Thus, the goal of this work is to model the rarefied gas flow in the MIKRA sensor under …

Formation Of Three-Dimensional Surface Waves On Deep-Water Using Elliptic Solutions Of Nonlinear Schrödinger Equation, Shahrdad G. Sajjadi, S.C. Mancas, Frederique Drullion

Publications

A review of three-dimensional waves on deep-water is presented. Three forms of three-dimensionality, namely oblique, forced and spontaneous types, are identified. An alternative formulation for these three-dimensional waves is given through cubic nonlinear Schrödinger equation. The periodic solutions of the cubic nonlinear Schrödinger equation are found using Weierstrass elliptic ℘ functions. It is shown that the classification of solutions depends on the boundary conditions, wavenumber and frequency. For certain parameters, Weierstrass ℘ functions are reduced to periodic, hyperbolic or Jacobi elliptic functions. It is demonstrated that some of these solutions do not have any physical significance. An analytical solution of …

Parallel Two-Dimensional Unstructured Anisotropic Delaunay Mesh Generation For Aerospace Applications, Juliette Kelly Pardue

Computer Science Theses & Dissertations

A bottom-up approach to parallel anisotropic mesh generation is presented by building a mesh generator from the principles of point-insertion, triangulation, and Delaunay refinement. Applications focusing on high-lift design or dynamic stall, or numerical methods and modeling test cases focus on two-dimensional domains. This push-button parallel mesh generation approach can generate high-fidelity unstructured meshes with anisotropic boundary layers for use in the computational fluid dynamics field.

A Hybrid Variational Iteration Method For Blasius Equation, M. Sajid, N. Ali, T. Javed

Applications and Applied Mathematics: An International Journal (AAM)

The objective of this paper is to present the hybrid variational iteration method. The proposed algorithm is based on the combination of variational iteration and shooting methods. In the proposed algorithm the entire domain is divided into subintervals to establish the accuracy and convergence of the approximate solution. It is found that in each subinterval a three term approximate solution using variational iteration method is sufficient. The proposed hybrid variational iteration method offers not only numerical values, but also closed form analytic solutions in each subinterval. The method is implemented using an example of the Blasius equation. The results show …

On The Analytic Solution For The Steady Drainage Of Magnetohydrodynamic (Mhd) Sisko Fluid Film Down A Vertical Belt, A. M. Siddiqui, Hameed Ashraf, T. Haroon, A. Walait

Applications and Applied Mathematics: An International Journal (AAM)

This paper presents an analytic study for the steady drainage of magnetohydrodynamic (MHD) Sisko fluid film down a vertical belt. The fluid film is assumed to be electrically conducting in the presence of a uniform transverse magnetic field. An analytic solution for the resulting non linear ordinary differential equation is obtained using the Adomian decomposition method. The effects of various available parameters especially the Hartmann number are observed on the velocity profile, shear stress and vorticity vector to get a physical insight of the problem. Furthermore, the shear thinning and shear thickening characteristics of the Sisko fluid are discussed. The …

Free Convective Chemically Absorption Fluid Past An Impulsively Accelerated Plate With Thermal Radiation Variable Wall Temperature And Concentrations, Sanjib Sengupta

Applications and Applied Mathematics: An International Journal (AAM)

The present paper deals with the theoretical study of thermal radiation and chemical reaction on free convective heat and mass transfer flow of a Newtonian viscous incompressible fluid past a suddenly accelerated semi–infinite vertical permeable plate immersed in Darcian absorption media. The fluid media is considered as optically thick and the Rosselend radiative heat flux model is incorporated in the energy equation. The governing equation of motions are first non-dimensionalised and then transformed into a set of ordinary differential equations by employing a suitable periodic transformation. The closed form of the expression for velocity, temperature and concentration fields as well …

Suspension Model For Blood Flow Through A Tapering Catheterized Inclined Artery With Asymmetric Stenosis, Devajyoti Biswas, Moumita Paul

Applications and Applied Mathematics: An International Journal (AAM)

We intend to study a particle fluid suspension model for blood flow through an axially asymmetric but radially symmetric mild stenosis in the annular region of an inclined tapered artery and a co-axial catheter in a suitable flow geometry has been considered to investigate the influence of velocity slip at the stenotic wall as well as hematocrit, shape parameter. The model also includes the tapering effect and inclination of the artery. Expressions for the flow variables have been derived analytically and their variations with various flow parameters are represented graphically. The results for the different values of the parameters involved …

Mathematical Modeling Of Two-Dimensional Unsteady Flow In Growing Tumor, N. Gracia, D. N. Riahi, R. Roy

Applications and Applied Mathematics: An International Journal (AAM)

We investigate the problem of unsteady fluid flow in growing solid tumors. We develop a mathematical model for a growing tumor whose boundary is taken as a sphere, and the unsteady fluid flow within the tumor is assumed to be two dimensional with respect to the radial distance and the latitudinal angle in spherical coordinates. The expressions for the time, radial and latitudinal variations of the flow velocity, pressure, and the two investigated drug concentrations within the tumor were determined analytically. We calculated these quantities in the tumor as well as in a corresponding normal tissue. We find, in particular, …

Unsteady Boundary Layer Flow Of Thermophoretic Mhd Nanofluid Past A Stretching Sheet With Space And Time Dependent Internal Heat Source/Sink, N. Sandeep, C. Sulochana, C. S. K. Raju, M. J. Babu, V. Sugunamma

Applications and Applied Mathematics: An International Journal (AAM)

In this study we analyze the boundary layer flow of a thermophoretic magnetohydrodynamic dissipative nanofluid over an unsteady stretching sheet in a porous medium with space and time dependent internal heat source/sink. The governing equations are transformed to ordinary differential equations by using similarity transformation. Numerical solutions of these equations are obtained by using the Shooting Technique. The effects of non-dimensional governing parameters on the velocity, temperature, concentration profiles, friction factor, Nusselt and Sherwood numbers are discussed and presented through graphs and tables. Accuracy of the results compared with the existing ones. Excellent agreement is found with earlier studies.

Transition Orbits Of Walking Droplets, Joshua Parker

Physics

It was recently discovered that millimeter-sized droplets bouncing on the surface of an oscillating bath of the same fluid can couple with the surface waves it produces and begin walking across the fluid bath. These walkers have been shown to behave similarly to quantum particles; a few examples include single-particle diffraction, tunneling, and quantized orbits. Such behavior occurs because the drop and surface waves depend on each other to exist, making this the first and only known macroscopic pilot-wave system. In this paper, the quantized orbits between two identical drops are explored. By sending a perturbation to a pair of …

A Study Of Mixing In A Magnetohydrodynamic (Mhd) Microfluidic Cell By Numerical Simulations, Fangping Yuan, Kakkattukuzhy M. Isaac

Collaborative Research: Actively Controllable Microfluidics with Film-Confined Redox-Magnetohydrodynamics -- Video and Data

No abstract provided.

Aggregation And Interfacial Behavior Of Charged Surfactants In Ionic Liquids, Lang Chen

Doctoral Dissertations

Room-temperature ionic liquids (ILs) exhibit a unique set of properties, leading to opportunities for numerous applications such as green solvents, batteries and lubricants. Their properties can be greatly tuned and controlled by addition of surfactants. It is therefore critical to obtain a better understanding of the aggregation and interfacial behavior of surfactants within ILs. Firstly, the phase diagram and aggregation isotherms of surfactants in several distinct ILs were investigated by solubility and tensiometry. A connection between solubility of the surfactant and the physical properties of the underlying ionic liquid was established. We found that the interfacial energy was crucial in …

A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

The phenomenon of overbanking tendency for a rigid-body, fixed-wing aircraft is investigated. Overbanking tendency is defined as a spontaneous, unbalanced rolling moment that keeps increasing an airplane’s bank angle in steep turns and must be arrested by opposite aileron action. As stated by the Federal Aviation Administration, the overbanking tendency may lead to a loss of control, especially in instrument meteorological conditions. It was found in this study that the speed differential over wing halves in horizontal turns indeed creates a rolling moment that achieves maximum values for bank angles between 45 and 55 degrees. However, this induced rolling moment …

A Unified And Preserved Dirichlet Boundary Treatment For The Cell-Centered Finite Volume Discrete Boltzmann Method, Leitao Chen, Laura A. Schaefer

Publications

A new boundary treatment is proposed for the finite volume discrete Boltzmann method (FVDBM) that can be used for accurate simulations of curved boundaries and complicated flow conditions. First, a brief review of different boundary treatments for the general Boltzmann simulations is made in order to primarily explain what type of boundary treatment will be developed in this paper for the cell-centered FVDBM. After that, the new boundary treatment along with the cell-centered FVDBM model is developed in detail. Next, the proposed boundary treatment is applied to a series of numerical tests with a detailed discussion of its qualitative and …

Advantages Of A Finite Extensible Nonlinear Elastic Potential In Lattice Boltzmann Simulations, Tai-Hsien Wu, Dewei Qi

The Hilltop Review

A new structure, generalized lattice nonlinear spring model (GLNSM), which adopts non-linear FENE-LJ potential instead of harmonic potential, has been coupled with lattice Boltzmann simulation for solving fluid-solid interaction problem. In this article, a significant work is the relationship between the GLNSM (FENE-LJ potential) and Young’s modulus has been described in detail. A validation has also been presented to prove that GLNSM is reliable.

Charged Particle Dynamics In The Magnetic Field Of A Long Straight Current-Carrying Wire, M. Fatuzzo, A. Prentice, T. Toepker

Faculty Scholarship

The article discusses the concept behind motion of a charged particle in a non-uniform filed of a wire carrying current. Topics discussed include possible types of motion in a current carrying field, vector analysis of velocity and magnetic field of the particle and Coupled differential equations.

New Interpretation Of Experimental Data On Si−As Alloy Solidification With Planar Interface, Sergey Sobolev

Sergey Sobolev

No abstract provided.