Fluid Dynamics Commons^™

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.

Inżynieria Chemiczna Ćw., Wojciech M. Budzianowski

Wojciech Budzianowski

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Tematyka Prac Doktorskich, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Moffatt Eddies In The Single Screw Extruder: Numerical And Analytical Study, Petru S. Fodor, Miron Kaufman

Miron Kaufman

A detailed analysis of the fluid flow in the single screw extruder is performed by combining numerical and analytical methods. While finite element analysis numerical models are used to extract the transversal velocity field, an analytical model in the limit of zero Reynolds numbers is used to determine the longitudinal component of the fluid velocities. The high resolution 3D model developed for the fluid flow in single screw extruders with aspect ratios (i.e. depth/width) ranging from 1 to 0.1, allows the identification of the position and extent of Moffatt eddies that impede the fluid mixing through the entire extruder’s volume. …

Effects Of Forcing Time Scale On The Simulated Turbulent Flows And Turbulent Collision Statistics Of Inertial Particles, B. Rosa, H. Parishani, O. Ayala, L.-P. Wang

Engineering Technology Faculty Publications

In this paper, we study systematically the effects of forcing time scale in the large-scale stochastic forcing scheme of Eswaran and Pope ["An examination of forcing in direct numerical simulations of turbulence," Comput. Fluids 16, 257 (1988)] on the simulated flow structures and statistics of forced turbulence. Using direct numerical simulations, we find that the forcing time scale affects the flow dissipation rate and flow Reynolds number. Other flow statistics can be predicted using the altered flow dissipation rate and flow Reynolds number, except when the forcing time scale is made unrealistically large to yield a Taylor microscale flow Reynolds …

Hamiltonian Approach To Internal Wave-Current Interactions In A Two-Media Fluid With A Rigid Lid, Alan Compelli, Rossen Ivanov

Articles

We examine a two-media 2-dimensional fluid system consisting of a lower medium bounded underneath by a flatbed and an upper medium with a free surface with wind generated surface waves but considered bounded above by a lid by an assumption that surface waves have negligible amplitude. An internal wave driven by gravity which propagates in the positive x-direction acts as a free common interface between the media. The current is such that it is zero at the flatbed but a negative constant, due to an assumption that surface winds blow in the negative x-direction, at the lid. We are concerned …

Plasma Processes And Cancer - Special Topical Cluster Of The 2nd Iwpct Meeting, Masaru Hori, Mounir Laroussi, Kai Masur, Yuzuru Ikehara

Electrical & Computer Engineering Faculty Publications

(First paragraph) Although the emerging multidisciplinary field of plasma medicine has been around for nearly two decades important advances have already taken place that could one day revolutionize healthcare and the way various challenging diseases can be treated.1-3Amongst these advances the effects of low temperature plasma (LTP) on cancer cells in vitro and in vivo stand out.4-13Current cancer treatment modalities, such as chemotherapy and radiation therapy, have serious side effects and tend to lose their benefits to the patients after a while. Therefore, novel and improved therapies that can be used alone …

Effects Of Gravity On The Acceleration And Pair Statistics Of Inertial Particles In Homogeneous Isotropic Turbulence, H. Parishani, O. Ayala, B. Rosa, L.-P. Wang, W. W. Grabowski

Engineering Technology Faculty Publications

Within the context of heavy particles suspended in a turbulent airflow, we study the effects of gravity on acceleration statistics and radial relative velocity (RRV) of inertial particles. The turbulent flow is simulated by direct numerical simulation (DNS) on a 256³ grid and the dynamics of O(10⁶) inertial particles by the point-particle approach. For particles/droplets with radius from 10 to 60 µm, we found that the gravity plays an important role in particle acceleration statistics: (a) a peak value of particle acceleration variance appears in both the horizontal and vertical directions at a particle Stokes number …

Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Rainich-Type Conditions For Perfect Fluid Spacetimes, Dionisios Krongos, Charles G. Torre

Research Vignettes

In this worksheet we describe and illustrate a relatively simple set of new Rainich-type conditions on an n-dimensional spacetime which are necessary and sufficient for it to define a perfect fluid solution of the Einstein field equations. Procedures are provided which implement these Rainich-type conditions and which reconstruct the perfect fluid from the metric. These results provide an example of the idea of geometrization of matter fields in general relativity, which is a purely geometrical characterization of matter fields via the Einstein field equations.

Scaling Group Analysis On Mhd Free Convective Heat And Mass Transfer Over A Stretching Surface With Suction / Injection, Heat Source/Sink Considering Viscous Dissipation And Chemical Reaction Effects, Hunegnaw Dessie, Naikoti Kishan

Applications and Applied Mathematics: An International Journal (AAM)

This paper concerns with scaling group analysis on MHD free convective heat and mass transfer over stretching surface considering effects of thermal-diffusion and diffusion-thermo with suction /injection, heat source/sink and chemical reaction by taking into account viscous dissipation. Scaling group transformations are used to convert the partial differential equations of governing equations into ordinary differential equation and are solved numerically by Keller Box Method. Numerical results obtained for different parameters are drawn graphically and their effects on velocity, temperature and concentration profiles are discussed and shown graphically. Skin-friction coefficient, Nusselt number and Sherwood number are presented in table. It is …

Steady Quadratic Stokes Flow Past Deformed Sphere: A Novel Perturbation Technique, Deepak K. Srivastava, Nirmal Srivastava, Raja R. Yadav

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, the problem of steady quadratic Stokes flow past a deformed sphere has been tackled with the use of a novel perturbation technique in both situations when a uniform stream is along the axis of symmetry (axial flow) and when it is perpendicular to the axis of symmetry (transverse flow). The most general form of the deformed sphere, governed by polar equation, is considered here for the study. The general expressions for axial and transverse Stokes drag for deformed sphere has been derived up to the second order of deformation parameter for parabolic and stagnation like parabolic flow. …

A Novel Approach For Solving Burger’S Equation, Amruta Daga, Vikas Pradhan

Applications and Applied Mathematics: An International Journal (AAM)

The paper presents a new analytical method called Variational Homotopy Perturbation Method (VHPM), which is a combination of the well-known Variational Iteration method (VIM) and the Homotopy Perturbation method (HPM) for solving the one-dimensional Burger’s equation. Two test problems are presented to demontrate the efficiency and the accuracy of the proposed method.The numerical solutions obtained are compared with the exact solution. Furthermore, this method does not require spatial discretization or restrictive assumptions and is free from round-off errors and therefore reduce the numerical computation significanly. The results reveal that the Variational Homotopy Perturbation Method is very effective and convenient to …

Effects Of Radiation Absorption And Thermo-Diffusion On Mhd Heat And Mass Transfer Flow Of A Micro-Polar Fluid In The Presence Of Heat Source, J. I. Oahimire, B. I. Olajuwon

Applications and Applied Mathematics: An International Journal (AAM)

An analysis of the heat and mass transfer effects on an unsteady flow of a micro-polar fluid over an infinite moving permeable plate in a saturated porous medium in the presence of a transverse magnetic field, radiation absorption and thermo-diffusion were studied. The governing system of partial differential equations was transformed to dimensionless equations using suitable dimensionless variables. The dimensionless equations were then solved analytically using perturbation technique to obtain the expressions for the velocity, micro-rotation, temperature and concentration. With the help of graphs, the effects of the various important parameters such as the translational velocity, micro-rotational velocity, temperature and …

Mitigation Of Moving Shocks In An Expanding Duct, Veraun Chipman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Inviscid flow theory governs the bulk motion of a gas at some distance away from the walls (i.e. outside the boundary layer). That is to say, there are no viscous forces in the bulk flow, which is modeled using the Euler equations. The Euler equations are simply the Navier-Stokes equations with zero viscosity terms. An ideal inviscid fluid, when brought into contact with a surface or wall, would naturally slip right past it since the fluid has no viscosity. In real life, however, a thin boundary layer forms between the wall or surface and the bulk flow. Shock wave boundary …

Stilling Basin Performance Analysis By Adv, Seyed Sobhan Aleyasin, Nima Fathi, Peter Vorobieff

Nima Fathi

Dynamics Of Skirting Droplets, Caleb Akers, Jacob Hale

Annual Student Research Poster Session

No abstract provided.