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 Title
 "ACETAZOLAMIDEINDUCED DECREASE OF APICAL FLUID FLOW IN CHOROID PLEXUS IS INDEPENDENT OF THE CONCOMITANT CHANGES IN AQUAPORIN1 EXPRESSION".
 Creator

Ameli, Pouya, Chan, Sic, University of Central Florida
 Abstract / Description

Acetazolamide (AZA), the only drug approved for treatment of hydrocephalus, is effective in only 2530% of patients while its effect on fluid flow in the choroid plexus (CP) is unknown. The drug reversibly inhibits Aquaporin 4 (AQP4), the most highly expressed "water pore" in the brain, and it is postulated that it reduces cerebrospinal fluid (CSF) production by modulating AQP1 (mostly found in the apical membrane of the CP). In this study, we sought to elucidate the effect of AZA on AQP1 and...
Show moreAcetazolamide (AZA), the only drug approved for treatment of hydrocephalus, is effective in only 2530% of patients while its effect on fluid flow in the choroid plexus (CP) is unknown. The drug reversibly inhibits Aquaporin 4 (AQP4), the most highly expressed "water pore" in the brain, and it is postulated that it reduces cerebrospinal fluid (CSF) production by modulating AQP1 (mostly found in the apical membrane of the CP). In this study, we sought to elucidate the effect of AZA on AQP1 and fluid flow in CP. Primary CP culture from p10 SpragueDawley rats and TRCSFB cell line were grown on Transwell permeable supports, treated with 100uM AZA or 100uM Vinpocetine (previously shown to increase AQP1 levels), and tested by: a) Fluid assays using TRITClabeled Dextran to assay direction and extent of fluid flow; b) Immunoblot, Immunocytochemistry (ICC), and RTPCR for AQP1 expression. Immnoblots and ICC analyses showed that AQP1 protein levels decrease in a delayed manner (lowest at 12 hours) with AZA treatment. The reduction in AQP1 protein was transient and preceded by a reduction in mRNA levels (lowest at 6 hours). Transwell fluid assays indicate a shift in fluid flow at 2 hours, prior to the changes in AQP1 mRNA or protein. Alteration of fluid flow by AZA (in both primary culture and TRCSFB) is similar to Vinpocetine's effect in primary culture. Together with druginduced alterations in AQP1 levels, these data suggest independent mechanisms behind fluid flow and AQP1 expression.
Show less  Date Issued
 2010
 Identifier
 CFE0003501, ucf:48935
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0003501
 Title
 Purge and Secondary Flow Interaction Control by Means of Platform Circumferential Contouring.
 Creator

Seco Soley, Melissa, Kapat, Jayanta, Deng, Weiwei, Gordon, Ali, University of Central Florida
 Abstract / Description

This study presents an attempt to reduce the losses produced by the purge flow in a turbine stage by incorporating circumferential platform contouring. Two contours are proposed and compared against a baseline at different levels of swirl. The computational simulations were performed using a RANS threedimensional Computational Fluid Dynamics code with the Shear Stress Transport turbulence model. The results of steady simulations demonstrate that for the first contour, when the flow is...
Show moreThis study presents an attempt to reduce the losses produced by the purge flow in a turbine stage by incorporating circumferential platform contouring. Two contours are proposed and compared against a baseline at different levels of swirl. The computational simulations were performed using a RANS threedimensional Computational Fluid Dynamics code with the Shear Stress Transport turbulence model. The results of steady simulations demonstrate that for the first contour, when the flow is swirled to 50% of the rim speed, the purge flow exits the cavity with less cross flow. This in turn reduces the strength of the passage vortex. However, at swirl extremes of 0% and 100% the baseline has the best performance. The results show that a carefully designed platform has the potential to reduce losses when the operating condition is in the proximity of 50% swirl.
Show less  Date Issued
 2011
 Identifier
 CFE0004163, ucf:49054
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0004163
 Title
 Numerical Study of Interfacial flow using Algebraic Coupled Level SetVolume of Fluid (ACLSVOF) Method.
 Creator

Haghshenas, Majid, Kumar, Ranganathan, Das, Tuhin, Ahmed, Kareem, Shivamoggi, Bhimsen, University of Central Florida
 Abstract / Description

Solving interfacial flows numerically has been a challenge due to the lack of sharpness and the presence of spurious currents at the interface. Two methods, Algebraic Coupled Level SetVolume of Fluid (ACLSVOF) method and Ghost Fluid Method (GFM) have been developed in the finite volume framework and employed in several interfacial flows such as RayleighTaylor instability, rising bubble, impinging droplet and crossflow oil plume. In the static droplet simulation, ACLSVOF substantially...
Show moreSolving interfacial flows numerically has been a challenge due to the lack of sharpness and the presence of spurious currents at the interface. Two methods, Algebraic Coupled Level SetVolume of Fluid (ACLSVOF) method and Ghost Fluid Method (GFM) have been developed in the finite volume framework and employed in several interfacial flows such as RayleighTaylor instability, rising bubble, impinging droplet and crossflow oil plume. In the static droplet simulation, ACLSVOF substantially reduces the spurious currents. The capillary wave relaxation shows that this method delivers results comparable to those of more rigorous methods such as Front Tracking methods for fine grids. The results for the other interfacial flows also compared well with the experimental results. Next, interfacial forces are implemented by enlisting the finite volume discretization of Ghost Fluid Method. To assess the ACLSVOF/GFM performance, four cases are studied. In the case of the static droplet in suspension, the combined ACLSVOF/GFM produces a sharp and accurate pressure jump compared to the traditional CSF (continuum surface force) implementation. For the linear twolayer shear flow, GFM sharp treatment of the viscosity captured the velocity gradient across the interface. For a gaseous bubble rising in a viscous fluid, GFM outperforms CSF by almost 10%. Also, a Decoupled Pressure ACLSVOF/GFM method (DPM) has been developed which separates pressure into two pressure components, one accounting for interfacial forces such as surface tension and another representing the rest of flow pressure. It is proven that the DPM implementation results in more efficiency in PISO (Pressure Implicit with Splitting of Operators) loop. A twophase solver is used to study buoyant oil discharge in quiescent and crossflow ambient. Different modes of breakup including dripping, jetting (axisymmetric and asymmetric) and atomization for crossflow oil jet are captured.
Show less  Date Issued
 2018
 Identifier
 CFE0007570, ucf:52582
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0007570
 Title
 ANALYTICAL AND NUMERICAL SOLUTIONS OF DIFFERENTIALEQUATIONS ARISING IN FLUID FLOW AND HEAT TRANSFER PROBLEMS.
 Creator

Sweet, Erik, Vajravelu, Kuppalapalle, University of Central Florida
 Abstract / Description

The solutions of nonlinear ordinary or partial differential equations are important in the study of fluid flow and heat transfer. In this thesis we apply the Homotopy Analysis Method (HAM) and obtain solutions for several fluid flow and heat transfer problems. In chapter 1, a brief introduction to the history of homotopies and embeddings, along with some examples, are given. The application of homotopies and an introduction to the solutions procedure of differential equations (used in the...
Show moreThe solutions of nonlinear ordinary or partial differential equations are important in the study of fluid flow and heat transfer. In this thesis we apply the Homotopy Analysis Method (HAM) and obtain solutions for several fluid flow and heat transfer problems. In chapter 1, a brief introduction to the history of homotopies and embeddings, along with some examples, are given. The application of homotopies and an introduction to the solutions procedure of differential equations (used in the thesis) are provided. In the chapters that follow, we apply HAM to a variety of problems to highlight its use and versatility in solving a range of nonlinear problems arising in fluid flow. In chapter 2, a viscous fluid flow problem is considered to illustrate the application of HAM. In chapter 3, we explore the solution of a nonNewtonian fluid flow and provide a proof for the existence of solutions. In addition, chapter 3 sheds light on the versatility and the ease of the application of the Homotopy Analysis Method, and its capability in handling nonlinearity (of rational powers). In chapter 4, we apply HAM to the case in which the fluid is flowing along stretching surfaces by taking into the effects of "slip" and suction or injection at the surface. In chapter 5 we apply HAM to a Magnetohydrodynamic fluid (MHD) flow in two dimensions. Here we allow for the fluid to flow between two plates which are allowed to move together or apart. Also, by considering the effects of suction or injection at the surface, we investigate the effects of changes in the fluid density on the velocity field. Furthermore, the effect of the magnetic field is considered. Chapter 6 deals with MHD fluid flow over a sphere. This problem gave us the first opportunity to apply HAM to a coupled system of nonlinear differential equations. In chapter 7, we study the fluid flow between two infinite stretching disks. Here we solve a fourth order nonlinear ordinary differential equation. In chapter 8, we apply HAM to a nonlinear system of coupled partial differential equations known as the Drinfeld Sokolov equations and bring out the effects of the physical parameters on the traveling wave solutions. Finally, in chapter 9, we present prospects for future work.
Show less  Date Issued
 2009
 Identifier
 CFE0002889, ucf:48017
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0002889
 Title
 Study of Transport Phenomena in CarbonBased Materials.
 Creator

Aboelsoud, Walid, Chow, Louis, Kumar, Ranganathan, Deng, Weiwei, Kar, Aravinda, University of Central Florida
 Abstract / Description

In aircooled heat exchangers, airside thermal resistance is usually the largest compared to conduction and liquidside thermal resistances. Thus, reducing the airside thermal resistance with finlike structures can greatly improve overall cooling performance. The performance of these structures is usually characterized by the rate of heat which can be transferred and the pumping power required. One promising solution is to use a highthermalconductivity material with a large surface per...
Show moreIn aircooled heat exchangers, airside thermal resistance is usually the largest compared to conduction and liquidside thermal resistances. Thus, reducing the airside thermal resistance with finlike structures can greatly improve overall cooling performance. The performance of these structures is usually characterized by the rate of heat which can be transferred and the pumping power required. One promising solution is to use a highthermalconductivity material with a large surface per unit volume such as carbon foam. This study presents a method of utilizing Vshape corrugated carbon foam. The airside heat transfer coefficient and the pressure drop across the foam have been investigated using different Vshape foam geometrical configurations obtained by varying its length and height. Based on design considerations and availability, the foam length has been chosen to be 25.4, 38.1 and 52.1 mm while its height is 4.4, 6.8 and 11.7 mm, resulting in nine different test pieces of foam with different heights and lengths.A total number of 81 experiments were carried out and results show that of the nine Vshape configurations, the foam with the shortest length and tallest height gives the best performance. Experimental results are also compared with the results of prior work using different carbon foam geometries. It is shown that Vshape corrugated carbon foam provides higher heat transfer coefficient and better overall performance.Numerical method is performed next. The effect of the foam length and height on thermal and hydraulic performance is demonstrated and discussed. There is excellent agreement between numerical and experimental results. An analysis is also made to better understand the transport phenomena that occur within the porous matrix. For laminar flow of air, one of the findings is the high heat transfer effectiveness of the foam which means a foam thickness of 1 mm or less is sufficient for heat transfer enhancement for air speed of up to 4 m/s. To demonstrate the feasibility of using carbon foam, an analytical case study of carbon foam heat exchanger was performed and compared to traditional heat exchanger with the same heat load. Results show that a volume saving of up to 55% can be obtained by using carbon foam instead of traditional aluminum fins.Another attractive carbonbased material is the highly oriented pyrolytic graphite (HOPG) which has an inplane thermal conductivity of about 1700 W/m.K and an outofplane k of about 8 W/m.K at room temperature. HOPG is a graphite material with a high degree of preferred crystallographic orientation. HOPG can be very useful in thermal applications when axial conduction is critical and needed to be minimized as in recuperators used in cryocoolers and compact power generation. Also, an analysis of HOPG for microchannel applications shows that the high inplane thermal conductivity of HOPG, which is far greater than that of copper and aluminum, allows a taller height for the microchannel. This translates to an increase in the heat flux removal rate by two to three times.
Show less  Date Issued
 2013
 Identifier
 CFE0005081, ucf:50732
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0005081
 Title
 VARIABLE FLUID FLOW REGIMES ALTER ENDOTHELIAL ADHERENS JUNCTIONS AND TIGHT JUNCTIONS.
 Creator

Ranadewa, Dilshan, Steward, Robert, Gou, Jihua, Mansy, Hansen, University of Central Florida
 Abstract / Description

Variable blood flow regimes influence a range of cellular properties ranging from cell orientation, shape, and permeability: all of which are dependent on endothelial cellcell junctions. In fact, cellcell junctions have shown to be an integral part of vascular homeostasis through the endothelium by allowing intercellular signaling and passage control through tight junctions (TJs), adherens junctions (AJs), and gap junctions (GJs). It was our objective to determine the structural response of...
Show moreVariable blood flow regimes influence a range of cellular properties ranging from cell orientation, shape, and permeability: all of which are dependent on endothelial cellcell junctions. In fact, cellcell junctions have shown to be an integral part of vascular homeostasis through the endothelium by allowing intercellular signaling and passage control through tight junctions (TJs), adherens junctions (AJs), and gap junctions (GJs). It was our objective to determine the structural response of both AJs and TJs under steady and oscillatory flow. Human brain microvascular endothelial cells (HBMECs) were cultured in a parallel plate flow chamber and exposed to separate trails of steady and oscillatory fluid shear stress for 24 hours. Steady flow regimes consisted of a low laminar flow (LLF) of 1 dyne/cm2, and a high laminar flow (HLF) of 10 dyne/cm2 and oscillatory flow regimes consisted of low oscillatory flow (LOF) +/ 1 dyne/cm2 and high oscillatory flow (HLF) of +/ 10 dyne/cm2. We then imaged the TJs ZO1 Claudin5 and AJs JAMA VECadherin and subsequently analyzed their structural response as a function of pixel intensity. Our findings revealed an increase in pixel intensity between LLF and LOF along the boundary of the cells in both TJs ZO1 Claudin 5. Therefore, our results demonstrate the variable response of different cellcell junctions under fluid shear, and for the first time, observes the difference in cellcell junctional structure amongst steady and oscillatory flow regimes
Show less  Date Issued
 2019
 Identifier
 CFE0007518, ucf:52618
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0007518
 Title
 Fluid Flow Characteristics of a CoFlow Fluidic Slot Jet Thrust Augmentation Propulsion System.
 Creator

Garrett, Brian, Ahmed, Kareem, Kapat, Jayanta, Bhattacharya, Samik, University of Central Florida
 Abstract / Description

The UAV industry is booming with investments in research and development on improving UAV systems in order to increase applications and reduce costs of the use of these machines. Current UAV machines are developed according to the quadcopter design which has a rotary propulsion system which provides the lift needed for the aerial vehicles. This design has some flaws; namely safety concerns and noise/vibration production both of which come from the rotary propulsion system. As such, a novel...
Show moreThe UAV industry is booming with investments in research and development on improving UAV systems in order to increase applications and reduce costs of the use of these machines. Current UAV machines are developed according to the quadcopter design which has a rotary propulsion system which provides the lift needed for the aerial vehicles. This design has some flaws; namely safety concerns and noise/vibration production both of which come from the rotary propulsion system. As such, a novel propulsion system using slip stream air passed through high performance slot jets is proposed and analysis of the fluid characteristics is presented in this report.The test section for the experiment is developed using 3D printed ABS plastic airfoils modified with internal cavities where pressurized air is introduced and then expelled through slot jets on the pressure side of the airfoils. Entrainment processes develop in the system through high momentum fluid introduction into a sedentary secondary fluid. Entrainment is governed by pressure gradients and turbulent mixing and so turbulent quantities that measure these processes are extracted and analyzed according to the independent variable's effects on these quantities. Pitot probe testing extracted one dimensional fluid information and PIV analysis is used to characterize the twodimensional flow aspects.High slot jet velocities are seen to develop flows dominated by convection pushing momentum mixing downstream reducing the mixing while low slot jet speeds exhibit higher mass fluxes and thrust development. Confinement spacing is seen to cause a decrease in flow velocity and thrust as the spacing is decreased for high speed runs. The most constricted cross sectional runs showed high momentum mixing and developed combined selfsimilar flow through higher boundary layer interactions and pressures, but this also hurt thrust development. The Angle of Attack of the assembly proved to be the most important variable. Outward angling showed the influence of coanda effects but also demonstrated the highest bulk fluid flow with turbulence driven momentum mixing. Inward angling created combined fluid flow downstream with high momentum mixing upstream driven by pressure. Minimal mixing is seen when the airfoils are not angled and high recirculation zones along the boundaries. The optimal setup is seen to when the airfoils are angled outwards where the highest thrust and bulk fluid movement is developed driven by the turbulent mixing induced by the increasing cross sectional area of the system.
Show less  Date Issued
 2019
 Identifier
 CFE0007636, ucf:52509
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0007636
 Title
 EFFECT OF CORIOLIS AND CENTRIFUGAL FORCES ON TURBULENCE AND TRANSPORT AT HIGH ROTATION AND BUOYANCY NUMBERS.
 Creator

Sleiti, Ahmad Khalaf, Kapat, Jay, University of Central Florida
 Abstract / Description

This study attempts to understand one of the most fundamental and challenging problems in fluid flow and heat transfer for rotating machines. The study focuses on gas turbines and electric generators for high temperature and high energy density applications, respectively, both which employ rotating cooling channels so that materials do not fail under high temperature and high stress environment.Prediction of fluid flow and heat transfer inside internal cooling channels that rotate at high...
Show moreThis study attempts to understand one of the most fundamental and challenging problems in fluid flow and heat transfer for rotating machines. The study focuses on gas turbines and electric generators for high temperature and high energy density applications, respectively, both which employ rotating cooling channels so that materials do not fail under high temperature and high stress environment.Prediction of fluid flow and heat transfer inside internal cooling channels that rotate at high rotation number and high density ratio similar to those that are existing in turbine blades and generator rotors is the main focus of this study. Both smoothwall and ribroughened channels are considered here. Rotation, buoyancy, bends, ribs and boundary conditions affect the flow inside theses channels. Introducing ribs inside internal cooling channel can enhance the heat transfer rate. As the introduction of ribs approach causes rapid increase in the severely limited pressure drop and requires high cost, other means of achieving high heat transfer rate are desired. Another approach to increase heat transfer rate to a values that are comparable to those achieved by introduction of ribs is to increase rotation number. One objective of this research is to study and compare theses two approaches in order to decide the optimum range of application and a possible replacement of the highcost and complex ribs by increasing rotation number.A fully computational approach is employed in this study. On the basis of comparison between twoequation (ke and kw) and RSM turbulence models, it is concluded that the twoequation turbulence models cannot predict the flow field and heat transfer correctly, while RSM showed improved prediction. For the near wall region, two approaches with standard wall functions and enhanced near wall treatment were investigated. The enhanced near wall approach showed superior results to the standard wall functions approach. Thus RSM with enhanced near wall treatment is validated against available experimental data (which are primarily at low rotation and buoyancy numbers). The model was then used for cases with high rotation numbers (as much as 1.29) and highdensity ratios (up to 0.4). Particular attention is given to how turbulence intensity, Reynolds stresses and transport are affected by Coriolis and buoyancy/centrifugal forces caused by high levels of rotation and density ratio. The results obtained are explained in view of physical interpretation of Coriolis and centrifugal forces. Investigation of channels with smooth and with ribroughened walls that are rotating about an orthogonal axis showed that increasing rotation number always enhances turbulence and the heat transfer rate, while at high rotation numbers, increasing density ratio although causes higher turbulence activity but dose not increase Nu and in some locations even decreases Nu. The increasing thermal boundary layer thickness near walls is the possible reason for this behavior of Nu. The heat transfer enhancement correlates linearly with rotation number and hence it is possible to derive linear correlation for the increase in Nu as a function of Ro. Investigation of channels with ribroughened walls that rotate about orthogonal axis showed that 4sideaverage Nur correlates with Ro linearly, where a linear correlation for Nur/Nus as a function of rotation number is derived. It is also observed that the heat transfer rate on smoothwall channel can be enhanced rapidly by increasing Ro to values that are comparable to the enhancement due to the introduction of ribs inside internal cooling channels. This observation suggests that ribs may be unnecessary in highspeed machines, and has tremendous implications for possible cost savings in these turbines.In square channels that are rotating about parallel axis, the heat transfer rate enhances by increasing Ro on three surfaces of the square channel and decreases on the fourth surface. Th
Show less  Date Issued
 2004
 Identifier
 CFE0000014, ucf:52854
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0000014
 Title
 Computational Fluid Dynamics Simulation of United Launch Alliance Delta IV Hydrogen Plume Mitigation Strategies.
 Creator

Guimond, Stephen, Kassab, Alain, Divo, Eduardo, Vasu Sumathi, Subith, University of Central Florida
 Abstract / Description

During the launch sequence of the United Launch Alliance Delta IV launch vehicle, large amounts of pure hydrogen are introduced into the launch table and ignited by RadialOutwardFiringIgniters (ROFIs). This ignition results in a significant flame, or plume, that rises upwards out of the launch table due to buoyancy. The presence of the plume causes increased and unwanted heat loads on the surface of the vehicle. A proposed solution is to add a series of fans and structures to the existing...
Show moreDuring the launch sequence of the United Launch Alliance Delta IV launch vehicle, large amounts of pure hydrogen are introduced into the launch table and ignited by RadialOutwardFiringIgniters (ROFIs). This ignition results in a significant flame, or plume, that rises upwards out of the launch table due to buoyancy. The presence of the plume causes increased and unwanted heat loads on the surface of the vehicle. A proposed solution is to add a series of fans and structures to the existing launch table configuration that are designed to inject ambient air in the immediate vicinity of the launch vehicle's nozzles to suppress the plume rise. In addition to the air injection, secondary fan systems can be added around the launch table openings to further suppress the hydrogen plume. The proposed air injection solution is validated by computational fluid dynamics simulations that capture the combustion and compressible flow observed during the Delta IV launch sequence. A solution to the hydrogen plume problem will have direct influence on the efficiency of the launch vehicle: lower heat loads result in thinner vehicle insulation and thus allow for a larger payload mass. Current results show that air injection around the launch vehicle nozzles and air suppression around the launch table openings significantly reduces the size of the plume around the launch vehicle prior to liftoff.
Show less  Date Issued
 2014
 Identifier
 CFE0005500, ucf:50345
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0005500
 Title
 SemiAnalytical Solutions of Nonlinear Differential Equations Arising in Science and Engineering.
 Creator

Dewasurendra, Mangalagama, Vajravelu, Kuppalapalle, Mohapatra, Ram, Rollins, David, Kumar, Ranganathan, University of Central Florida
 Abstract / Description

Systems of coupled nonlinear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higherorder deformation equation by...
Show moreSystems of coupled nonlinear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higherorder deformation equation by spending lots of CPU time. However, in the latest innovation of Liao's " Method of Directly Defining inverse Mapping (MDDiM)" which he introduced to solve a single nonlinear ordinary differential equation has great freedom to define the inverse linear map directly. In this way, one can solve higher order deformation equations quickly, and it is unnecessary to calculate an inverse linear operator.Our primary goal is to extend MDDiM to solve systems of coupled nonlinear ordinary differential equations. In the first chapter, we will introduce MDDiM and briefly discuss the advantages of MDDiM Over OHAM. In the second chapter, we will study a nonlinear coupled system using OHAM. Next three chapters, we will apply MDDiM to coupled nonlinear systems arise in mechanical engineering to study fluid flow and heat transfer. In chapter six we will apply this novel method to study coupled nonlinear systems in epidemiology to investigate how diseases spread throughout time. In the last chapter, we will discuss our conclusions and will propose some future work. Another main focus is to compare MDDiM with OHAM.
Show less  Date Issued
 2019
 Identifier
 CFE0007624, ucf:52551
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0007624
 Title
 A MODEL INTEGRATED MESHLESS SOLVER (MIMS) FOR FLUID FLOW AND HEAT TRANSFER.
 Creator

Gerace, Salvadore, Kassab, Alain, University of Central Florida
 Abstract / Description

Numerical methods for solving partial differential equations are commonplace in the engineering community and their popularity can be attributed to the rapid performance improvement of modern workstations and desktop computers. The ubiquity of computer technology has allowed all areas of engineering to have access to detailed thermal, stress, and fluid flow analysis packages capable of performing complex studies of current and future designs. The rapid pace of computer development, however,...
Show moreNumerical methods for solving partial differential equations are commonplace in the engineering community and their popularity can be attributed to the rapid performance improvement of modern workstations and desktop computers. The ubiquity of computer technology has allowed all areas of engineering to have access to detailed thermal, stress, and fluid flow analysis packages capable of performing complex studies of current and future designs. The rapid pace of computer development, however, has begun to outstrip efforts to reduce analysis overhead. As such, most commercially available software packages are now limited by the human effort required to prepare, develop, and initialize the necessary computational models. Primarily due to the meshbased analysis methods utilized in these software packages, the dependence on model preparation greatly limits the accessibility of these analysis tools. In response, the socalled meshless or meshfree methods have seen considerable interest as they promise to greatly reduce the necessary human interaction during model setup. However, despite the success of these methods in areas demanding high degrees of model adaptability (such as crack growth, multiphase flow, and solid friction), meshless methods have yet to gain notoriety as a viable alternative to more traditional solution approaches in general solution domains. Although this may be due (at least in part) to the relative youth of the techniques, another potential cause is the lack of focus on developing robust methodologies. The failure to approach development from a practical perspective has prevented researchers from obtaining commercially relevant meshless methodologies which reach the full potential of the approach. The primary goal of this research is to present a novel meshless approach called MIMS (Model Integrated Meshless Solver) which establishes the method as a generalized solution technique capable of competing with more traditional PDE methodologies (such as the finite element and finite volume methods). This was accomplished by developing a robust meshless technique as well as a comprehensive model generation procedure. By closely integrating the model generation process into the overall solution methodology, the presented techniques are able to fully exploit the strengths of the meshless approach to achieve levels of automation, stability, and accuracy currently unseen in the area of engineering analysis. Specifically, MIMS implements a blended meshless solution approach which utilizes a variety of shape functions to obtain a stable and accurate iteration process. This solution approach is then integrated with a newly developed, highly adaptive model generation process which employs a quaternary triangular surface discretization for the boundary, a binarysubdivision discretization for the interior, and a unique shadow layer discretization for nearboundary regions. Together, these discretization techniques are able to achieve directionally independent, automatic refinement of the underlying model, allowing the method to generate accurate solutions without need for intermediate human involvement. In addition, by coupling the model generation with the solution process, the presented method is able to address the issue of illconstructed geometric input (small features, poorly formed faces, etc.) to provide an intuitive, yet powerful approach to solving modern engineering analysis problems.
Show less  Date Issued
 2010
 Identifier
 CFE0003299, ucf:48489
 Format
 Document (PDF)
 PURL
 http://purl.flvc.org/ucf/fd/CFE0003299