Mechanical Engineering Commons^™

Morton-Ordered Gpu Lattice Boltzmann Cfd Simulations With Application To Blood Flow, Gerald Gallagher, Fergal J. Boyle

Conference Papers

Computational fluid dynamics (CFD) is routinely used for numerically predicting cardiovascular-system medical device fluid flows. Most CFD simulations ignore the suspended cellular phases of blood due to computational constraints, which negatively affects simulation accuracy. A graphics processing unit (GPU) lattice Boltzmann-immersed boundary (LB-IB) CFD software package capable of accurately modelling blood flow is in development by the authors, focusing on the behaviour of plasma and stomatocyte, discocyte and echinocyte red blood cells during flow. Optimised memory ordering and layout schemes yield significant efficiency improvements for LB GPU simulations. In this work, comparisons of row-major-ordered Structure of Arrays (SoA) and Collected …

Pymoocfd - A Multi-Objective Optimization Framework For Cfd, George Martin Cunningham Love

Graduate College Dissertations and Theses

Modern computational resource have solidified the use of computer modeling as an integral part of the engineering design process. This is particularly impressive when it comes to high-dimensional models such as computational fluid dynamics (CFD) models. CFD models are now capable of producing results with a level of confidence that would previously have required physical experimentation. Simultaneously, the development of machine learning techniques and algorithms has increased exponentially in recent years. This acceleration is also due to the widespread availability of modern computational resources. Thus far, the cross-over between these fields has been mostly focused on computer models with low …

Flow Characterization In Mine Ventilation Fan Blade Design Using Cfd, Anwar Endris Hassen

Journal of Sustainable Mining

In axial ventilation fans, the generation of a uniform flow velocity is desirable for better efficiency. To that end, different fan blade types have been developed to achieve better flow uniformity. This article aimed to characterize the flow distribution and its uniformity in four blade designs, namely constant chord, tapered blade, skewed blade, and tapered skewed blade, using Computational Fluid Dynamics (CFD). The study employs an iterative study where key study decisions are made as the study progresses. The study began with the selection of a blade profile for the study. A comparative study between the NACA seven-digit and four-digit …

Particle Injection Simulation On Cold Spray Technology, Christopher A. Santini

Electronic Theses and Dissertations

Computational Fluid Dynamics (CFD) is a useful tool when it comes to research in the fields of Aerodynamics, Turbomachinery, and is used in several other fields of research. CFD is an important tool in the engineering industry because it allows for understanding and evaluation of a new design, this can lead to advancements in developing a more efficient and effective design. This tool helps in the understanding of the flow phenomena and how it can interact with its surroundings. One of the main reasons in the use of CFD is to reduce the cost of testing a design by running …

Magnetic Control Of Transport Of Particles And Droplets In Low Reynolds Number Shear Flows, Jie Zhang

Doctoral Dissertations

“Magnetic particles and droplets have been used in a wide range applications including biomedicine, biological analysis and chemical reaction. The manipulation of magnetic microparticles or microdroplets in microscale fluid environments is one of the most critical processes in the systems and platforms based on microfluidic technology. The conventional methods are based on magnetic forces to manipulate magnetic particles or droplets in a viscous fluid.

In contrast to conventional magnetic separation method, several recent experimental and theoretical studies have demonstrated a different way to manipulate magnetic non-spherical particles by using a uniform magnetic field in the microchannel. However, the fundamental mechanism …

A Cfd Study Of Steady Fully Developed Laminar Flow Through A 90-Degree Bend Pipe With A Square Cross-Sectional Area, Subodh Sushant Toraskar

Mechanical & Aerospace Engineering Theses & Dissertations

Fluid flow through a closed curved conduit has always been a topic of extensive research, as it has many practical and industrial applications. The flow is generally characterized by a presence of secondary flow, vortical motions and pressure losses for different flow regimes. These observed irregularities may positively or negatively impact the flow. They are beneficial for cases where mixing of fluids is required, usually observed for multiphase flow regimes or detrimental for cases involving particles in the fluid. There are also instances where a particle-laden fluid transported through the curved pipe was directly related to corrosion- erosion related problems. …

Fedsm 2018 Presentation, Nima Fathi, Peter Vorobieff, Seyed Sobhan Aleyasin, Goodarz Ahmadi

Nima Fathi

Transformation Of Nonlinear Waves In The Presence Of Wind, Current, And Vegetation, Haifei Chen

Electronic Theses and Dissertations

Accurate prediction of extreme wave events is crucial for the safe maritime activities and offshore operations. Improved knowledge of wave dissipation mechanisms due to breaking and vegetation leads to accurate wave forecast, protecting life and property along the coast. The scope of the thesis is to examine the wave transformations in the presence of wind, current, and vegetation, using a two-phase flow solver based on the open-source platform OpenFOAM. The Reynolds-Averaged Navier-Stokes (RANS) equations are coupled with a Volume of Fluid (VOF) surface capturing scheme and a turbulence closure model. This RANS-VOF model is adapted to develop a numerical wind-wave-current …

A Physics-Based Approach To Modeling Wildland Fire Spread Through Porous Fuel Beds, Tingting Tang

Theses and Dissertations--Mechanical Engineering

Wildfires are becoming increasingly erratic nowadays at least in part because of climate change. CFD (computational fluid dynamics)-based models with the potential of simulating extreme behaviors are gaining increasing attention as a means to predict such behavior in order to aid firefighting efforts. This dissertation describes a wildfire model based on the current understanding of wildfire physics. The model includes physics of turbulence, inhomogeneous porous fuel beds, heat release, ignition, and firebrands. A discrete dynamical system for flow in porous media is derived and incorporated into the subgrid-scale model for synthetic-velocity large-eddy simulation (LES), and a general porosity-permeability model is …

Numerical And Experimental Study Of Liquid Breakup Process In Solid Rocket Motor Nozzle, Yi-Hsin Yen

Theses and Dissertations

Rocket propulsion is an important travel method for space exploration and national defense, rockets needs to be able to withstand wide range of operation environment and also stable and precise enough to carry sophisticated payload into orbit, those engineering requirement makes rocket becomes one of the state of the art industry. The rocket family have been classified into two major group of liquid and solid rocket based on the fuel phase of liquid or solid state. The solid rocket has the advantages of simple working mechanism, less maintenance and preparing procedure and higher storage safety, those characters of solid rocket …

Project Oasis: Optimizing Aquaponic Systems To Improve Sustainability, Siddharth Nigam, Paige Balcom

Honors Theses and Capstones

Started in Fall 2015, Project OASIS (Optimizing Aquaponic Systems to Improve Sustainability) is an interdisciplinary capstone project with the goal of designing a sustainable and affordable small-scale aquaponic system for use in developing nations to tackle the problems of malnutrition and food insecurity. Aquaponics is a symbiotic relationship between fish and vegetables growing together in a recirculating system. The project’s goals were to minimize energy consumption and construction costs while using universally available materials. The computational fluid dynamics (CFD) software OpenFOAM was used to create transient and steady-state models of fish tanks to visualize velocity profiles, streamlines, and particle movement. …

Modelling Three-Phase Flow In Metallurgical Processes, Christoph Goniva, Gijsbert Wierink, Kari Heiskanen, Stefan Pirker, Christoph Kloss

Gijsbert Wierink

The interaction between gasses, liquids, and solids plays a critical role in many processes, such as coating, granulation and the blast furnace process. In this paper we present a comprehensive numerical model for three phase flow including droplets, particles and gas. By means of a coupled Computational Fluid Dynamics (CFD) - Discrete Element Method (DEM) approach the physical core phenomena are pictured at a detailed level. Sub-models for droplet deformation, breakup and coalescence as well as droplet-particle and wet particle-particle interaction are applied. The feasibility of this model approach is demonstrated by its application to a rotating drum coater. The …

Investigation Of Heat Transfer And Flow Using Ribs Within Gas Turbine Blade Cooling Passage: Experimental And Hybrid Les/Rans Modeling, Sourabh Kumar

Theses and Dissertations

Gas turbines are extensively used for aircraft propulsion, land based power generation and various industrial applications. Developments in innovative gas turbine cooling technology enhance the efficiency and power output, with an increase in turbine rotor inlet temperatures. These advancements of turbine cooling have allowed engine design to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on the increase of heat transfer areas and on promotion of turbulence of the cooling flow. In this study, it is obtained by casting repeated continuous V and broken V shaped …

Employing The Spectral Collocation Method In The Modeling Of Laminar Tube Flow Dynamics, Corey Michael Thibeault

All Graduate Theses, Dissertations, and Other Capstone Projects

The spectral collocation method is a numerical approximation technique that seeks the solution of a differential equation using a finite series of infinitely differentiable basis functions. This inherently global technique enjoys an exponential rate of convergence and has proven to be extremely effective in computational fluid dynamics. This paper presents a basic review of the spectral collocation method. The derivation is driven with an example of the approximation to the solution of a 1D Helmholtz equation. A Matlab code modeling two fluid dynamics problems is then given. First, the classic two-dimensional Graetz problem is simulated and compared to an analytical …

Experimental And Numerical Study Of A Proton Exchange Membrane Electrolyzer For Hydrogen Production, Sachin S. Deshmukh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen as a fuel source has received attention from researchers globally due to its potential to replace fossil based fuels for energy production. Research is being performed on hydrogen production, storage and utilization methods to make its use economically feasible relative to current energy sources. The PEM electrolyzer is used to produce hydrogen and oxygen using water and electricity. Focus of our study is to provide a benchmark experiment and numerical model of a single cell electrolyzer that can assist in improving the current state of understanding of this system. Parametric analysis of an experimental cell was performed to understand …

Numerical Simulation Of The Filling And Curing Stages In Reaction Injection Moulding, Using Ansys Cfx, Rui Igreja

Rui Igreja

Commonly used methods for injection moulding simulation involve a considerable number of simplifications, leading to a significant reduction of the computational effort but, in some cases also to limitations. In this work, Reaction Injection Moulding (RIM) simulations are performed with a minimum of simplifications, by using the general purpose CFD software package Ansys CFX, designed for numerical simulation of fluid flow and heat and mass transfer. The Ansys CFX’s homogeneous multiphase flow model, which is generally considered to be the appropriate choice for modelling free surface flows where the phases are completely stratified and the interface is well defined, is …