Fluid Dynamics Commons^™

Drag Reduction Using Graphene In Viscous Laminar Flow With Water And Isopropanol, Jessica M. Patalano, Akm Newaz Dr.

STAR Program Research Presentations

America has over 2.6 million miles of pipeline for the transportation of energy products, such as liquid petroleum and natural gas. Friction is one of the main sources for energy dissipation at liquid/solid interfaces that limits the transport of a fluid through a cylindrical pipe or tube. In order to make these pipelines more efficient and enhance the flow of these materials, it is necessary to find a coating material that reduces the frictional drag. The ideal material would reduce the drag between the fluid and solid interface while being easily synthesizable on the surface. The goal of this project …

Characterizing Nanoparticle Size By Dynamic Light Scattering, M. Zaman, S. Ang, S. Singh

Journal of the Arkansas Academy of Science

The Dynamic Light Scattering (DLS) Technique was used to determine the size, shape and diffusion coefficient of rod-like nanoparticles. The intensity auto-correlation functions of light scattered by particles in a solution were measured and analyzed to obtain the relaxation rates for decay of intensity correlations. These decay rates are related to the diffusion coefficients pertaining to the motion of the particle. In the case of nanorods, there are two types of motion - translational and rotational. By disentangling the relaxation rates, corresponding to these two types of motion, the shape and size of nanoparticles were characterized. These experiments, though limited …

The Dynamics Of Flat Surface Internal Geophysical Waves With Currents, Alan Compelli, Rossen Ivanov

Articles

A two-dimensional water wave system is examined consisting of two discrete incompressible fluid domains separated by a free common interface. In a geophysical context this is a model of an internal wave, formed at a pycnocline or thermocline in the ocean. The system is considered as being bounded at the bottom and top by a flatbed and wave-free surface respectively. A current profile with depth-dependent currents in each domain is considered. The Hamiltonian of the system is determined and expressed in terms of canonical wave-related variables. Limiting behavior is examined and compared to that of other known models. The linearised …

Electron Shock Waves With A Large Current Behind The Shock Front, H. D. Newberry, M. Hemmati, H. D. Moore, K. Ledbetter, M. W. Bowman

Journal of the Arkansas Academy of Science

The propagation of breakdown waves in a gas, which is primarily driven by electron gas pressure, is described by a one-dimensional, steady-state, three-component (electrons, ions, and neutral particles) fluid model. We consider the electron gas partial pressure to be much larger than that of the other species and the waves to have a shock front. Our set of equations consists of the equations of conservation of the flux of mass, momentum, and energy coupled with Poisson’s equation. This set of equations is referred to as the electron fluid dynamical equations. In this study we are considering breakdown waves propagating in …

Quantitative Assessment Of Secondary Flows Of Single-Phase Fluid Through Pipe Bends, Z. Kaldy, O. Ayala

Engineering Technology Faculty Publications

Single-phase fluid flow was simulated passing through various three dimensional pipe elbows. The simulations varied by Reynolds number, curvature ratios, and sweep angles and were all conducted using the k-e model available in COMSOL Multiphysics 5.1. The intent of this research was to qualitatively assess the flow characteristics under several different conditions. Many similarities were seen especially when comparing curvature ratios, the vorticity location for the turbulent cases show near identical behavior at the elbow midsection. One of the variables quantified in this paper is the maximum secondary velocity module which shows increasing values until the midsection of the elbow.

Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala

Engineering Technology Faculty Publications

A simulated study of oil and water in 90 degree bend was carried on COMSOL 5.1 to characterize flow pattern and analyze the secondary flow. The Euler-Euler k-e Reynolds Averaged Navier-Stokes model was used to represent the fluid motion. Changes in the Reynolds number, curvature ratio and direction of gravity were made to evaluate the effects in the intensity of the secondary flow. In the end, it was possible to see that the bend direction does not affect the formation of secondary flow for Reynolds above 100,000. It appears that the fluid behavior on the pipe bend is strongly related …

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …

Complex Capillary Fluidic Phenomena For Passive Control Of Liquids In Low-Gravity Environments, Logan Torres

Maseeh Summer Undergraduate Research Experience

In an effort to further apply the recent results of puddle jumping research, we seek to expand the oblique droplet impact studies of others by exploiting large liquid droplets in the near weightless environment of a drop tower. By using the spontaneous puddle jump mechanism, droplets of volumes 1 mL ≤ V ≤ 3 mL with corresponding Weber numbers of We ≈ 1 are impinged on surfaces inclined in the range 40° ≤ α ≤ 80° (measured from the horizontal plane). Impact surface wetting characteristics exhibit static contact angles θstatic = 165 ± 5°. All impacts result in complete rebound. …

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

LSU 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 …

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 …

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.

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.

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.

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 …

Thrust Prediction For A Rotor Operating In A Ship Airwake, Mathew Thomas

Mechanical & Aerospace Engineering Theses & Dissertations

This report details work performed at Old Dominion University focused on developing a thrust prediction capability for a rotor operating in a ship airwake. The study has built upon previous experimental work utilizing particle image velocimetry-based velocity field measurements to quantify the degree of coupling in a simplified rotor/ship airwake experiment. Using the velocity field data of the previous study, a database was built representing the volume over the landing deck. Rotor thrust was computed using blade element methods and compared to direct load cell measurements and to a superposed velocity field. Results show that the blade element method has …

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

LSU 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.

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 …

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 …

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 …

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.

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 …

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.

Performance Characteristics Of Fluidic-Based Thrust Augmentation Using A Slot Jet For Unmanned Aerial Vehicle Propulsion, Brendan A. Wiedow

Mechanical & Aerospace Engineering Theses & Dissertations

Currently most small vertical takeoff and landing Unmanned Aerial Vehicles (UA V's) use a quadcopter design by utilizing four exposed blades rotating at high RPMs around a central array of components. The research performed in this thesis is focused on understanding the underlying fluid dynamics of a slot jet through the use of flow entrainment for thrust augmentation with the application to be integrated into a novel UAV system with no external moving parts. Current publicly available quadcopter rotor design type aircraft were used as a basis for the design target weight and power to estimate the amount of thrust …