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Newton, Michael James. "Experimental mechanical and fluid mechanical investigations of the brass instrument lip-reed and the human vocal folds". Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3140.
Pełny tekst źródłaDhruv, Akash. "A Multiphase Solver for High-Fidelity Phase-Change Simulations over Complex Geometries". Thesis, The George Washington University, 2021. http://pqdtopen.proquest.com/#viewpdf?dispub=28256871.
Pełny tekst źródłaEmmanuelli, Gustavo. "An Assessment of State Equations of Air for Modeling a Blast Load Simulator". Thesis, Mississippi State University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10979719.
Pełny tekst źródłaWhen an explosive detonates above ground, air is principally the only material involved in the transmission of shock waves that can result in damage. Hydrodynamic codes that simulate these explosions use equations of state (EOSs) for modeling the behavior of air at these high-pressure, high-velocity conditions. An investigation is made into the effect that the EOS selection for air has on the calculated overpressure-time waveforms of a blast event. Specifically, the ideal gas, Doan-Nickel, and SESAME EOSs in the SHAMRC code were used to reproduce experiments conducted at the Blast Load Simulator (BLS), a large-scale shock tube operated by the U.S. Army Engineer Research and Development Center, that consisted of subjecting an instrumented rigid box at three angles of orientation inside the BLS to a blast environment. Numerical comparisons were made against experimentally-derived confidence intervals using peak values and several error metrics, and an attempt was made to rank the EOS based on performance. Issues were noted with the duration of decay from maximum pressure to negative phase that resulted in a general underprediction of the integrated impulse regardless of EOS, while the largest errors were noted for gages on faces at 45 to 90 degrees from the initial flow direction. Although no significant differences were noticed in the pressure histories from different EOSs, the ideal gas consistently ranked last in terms of the error metrics considered and simultaneously required the least computing resources. Similarly, the Doan-Nickel EOS slightly performed better than SESAME while requiring additional wallclock time. The study showed that the Doan-Nickel and SESAME EOSs can produce blast signatures with less errors and more matches in peak pressure and impulse than the ideal gas EOS at the expense of more computational requirements.
Faletra, Melissa Kathleen. "Segregation of Particles of Variable Size and Density in Falling Suspension Droplets". ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/265.
Pełny tekst źródłaTourbier, Dietmar 1964. "Numerical investigation of transitional and turbulent compressible axisymmetric wakes". Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282242.
Pełny tekst źródłaChemama, Michael Leopold. "Flames, Splashes and Microdroplets: A Mathematical Approach to Three Fluid Dynamics Problems". Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:14226101.
Pełny tekst źródłaAkbari, Mohammad Hadi. "Bluff-body flow simulations using vortex methods". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq55294.pdf.
Pełny tekst źródłaLaradji, Mohamed. "Ternary mixtures of water, oil and surfactants : equilibrium and dynamics". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39483.
Pełny tekst źródłaFurthermore, we have studied the effects of surfactants on the dynamics of phase separation of two immiscible fluids, and found a drastic alteration in the kinetics. In particular, we found that surfactants slow down the growth to a non-algebraic one leading eventually to a microphase separation.
Hausner, Alejo. "Non-linear effects in pulsating pipe flow". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61228.
Pełny tekst źródłaElkouh, Nabil. "Laminar natural convection and interfacial heat flux distributions in pure water-ice systems". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40347.
Pełny tekst źródłaAttention was found on pure water and water-ice systems contained in a long cylindrical enclosure of square cross-section. One wall was maintained at a constant temperature equal to or less than $0 sp circ$C; the opposite wall was maintained at a constant temperature above the density inversion temperature of water; the other two walls of the cross-section were essentially adiabatic. Several angles of inclination, $ Theta ,$ of the hot and cold walls, with respect to the gravitational acceleration vector, were considered: $ Theta = 0 sp circ , 30 sp circ , 45 sp circ ,$ and ${-}45 sp circ .$ For these conditions, the natural convection in water is governed by three nondimensional parameters: the Rayleigh number, Ra; a density inversion parameter, R; and the Prandtl number, Pr. The following ranges of these parameters were investigated: $10 sp3 le Ra le 3.37 times 10 sp7; 0.1 le R le 0.9;$ and $6.74 le Pr le 12.4.$
A complete rig was designed and constructed. The water-ice interface positions were obtained using shadowgraphy and computer-aided image processing techniques. In the complementary numerical work, a staggered-grid finite volume method (FVM) and a co-located, equal-order, control-volume finite element method (CVFEM) were formulated and used.
In the first investigation, variable- and constant-property models (VPM and CPM) were used. Results of the VPM and CPM were found to be similar, except when the values of R are in the vicinity of 0.5, where significant differences in the flow patterns, but only minor changes in the overall Nusselt number, $ overline{Nu},$ were observed. It was demonstrated that the fluid flow is extremely sensitive to changes in the value of R in the vincinity of 0.5. A correlation that gives the $ overline{Nu}$ as a function of Ra and R has been proposed for the vertical enclosure $( Theta = 0 sp circ ).$
In the proposed experimental/numerical technique to determine the interfacial heat flux distributions, the interface position obtained by the shadowgraphy and image processing techniques was used as an input to the CVFEM. The CVFEM was then used to solve the heat conduction problem in the ice and obtain the interfacial heat flux distribution. It was found that if the raw digitized interface position data are directly inputted to the CVFEM simulations of heat conduction in the ice, the interfacial heat flux distributions exhibit physically untenable fluctuations. The reasons for this difficulty were identified and successfully overcome using appropriate data filtering techniques. (Abstract shortened by UMI.)
Petel, Oren E. "A study of the failure mechanism of detonations in homogeneous and heterogeneous explosives /". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99530.
Pełny tekst źródłaSudarsan, Rangarajan. "Numerical investigation of shear-driven flow in a toroid of square cross-section". Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279918.
Pełny tekst źródłaDeSilva, Sirilath. "Transient axisymmetric model for laser drilling". Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/289927.
Pełny tekst źródłaBen-Yeoshua, Moshe 1957. "Coaxial jets with swirl". Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/291734.
Pełny tekst źródłaBarnes, Caleb J. "Unsteady Physics and Aeroelastic Response of Streamwise Vortex-Surface Interactions". Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1431937866.
Pełny tekst źródłaNiederhaus, Charles Edward. "Experiments on the Richtmyer-Meshkov instability of incompressible fluids". Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284290.
Pełny tekst źródłaFerris, Ryan J. "Numerical investigations of flow past a partially rotating stepped cylinder". Thesis, California State University, Long Beach, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1570832.
Pełny tekst źródłaNumerical investigations of flow past a partially rotating, circular cross-section, stepped cylinder in uniform flow at varying velocity ratios, diameter ratios and Reynolds Numbers are performed. The resulting flow fields are analyzed visually for the effect of rotation on the wake and numerically for the effect on lift/drag forces as well as vortex shedding rates. Simulations are run where either the large or small-diameter cylinder was rotating while the other cylinder was held stationary. Simulations were performed with end plates to minimize end effects. Results show with increasing the velocity ratio when the large cylinder rotates, vortex shedding is suppressed across the entire wake span. Comparatively, an increase in velocity ratio for the small-diameter cylinder during rotation results in increased wake activity and a larger drag force.
Siegel, Stefan Gunther. "Experimental investigation of the wake behind an axisymmetric bluff body". Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/284134.
Pełny tekst źródłaSalary, Roozbeh Ross. "Computational Fluid Dynamics Modeling and in situ Physics-Based Monitoring of Aerosol Jet Printing toward Functional Assurance of Additively-Manufactured, Flexible and Hybrid Electronics". Thesis, State University of New York at Binghamton, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10840384.
Pełny tekst źródłaAerosol jet printing (AJP)—a direct-write, additive manufacturing technique—has emerged as the process of choice particularly for the fabrication of flexible and hybrid electronics. AJP has paved the way for high-resolution device fabrication with high placement accuracy, edge definition, and adhesion. In addition, AJP accommodates a broad range of ink viscosity, and allows for printing on non-planer surfaces. Despite the unique advantages and host of strategic applications, AJP is a highly unstable and complex process, prone to gradual drifts in machine behavior and deposited material. Hence, real-time monitoring and control of AJP process is a burgeoning need. In pursuit of this goal, the objectives of the work are, as follows: (i) In situ image acquisition from the traces/lines of printed electronic devices right after deposition. To realize this objective, the AJP experimental setup was instrumented with a high-resolution charge-coupled device (CCD) camera, mounted on a variable-magnification lens (in addition to the standard imaging system, already installed on the AJ printer). (ii) In situ image processing and quantification of the trace morphology. In this regard, several customized image processing algorithms were devised to quantify/extract various aspects of the trace morphology from online images. In addition, based on the concept of shape-from-shading (SfS), several other algorithms were introduced, allowing for not only reconstruction of the 3D profile of the AJ-printed electronic traces, but also quantification of 3D morphology traits, such as thickness, cross-sectional area, and surface roughness, among others. (iii) Development of a supervised multiple-input, single-output (MISO) machine learning model—based on sparse representation for classification (SRC)—with the aim to estimate the device functional properties (e.g., resistance) in near real-time with an accuracy of ≥ 90%. (iv) Forwarding a computational fluid dynamics (CFD) model to explain the underlying aerodynamic phenomena behind aerosol transport and deposition in AJP process, observed experimentally.
Overall, this doctoral dissertation paves the way for: (i) implementation of physics-based real-time monitoring and control of AJP process toward conformal material deposition and device fabrication; and (ii) optimal design of direct-write components, such as nozzles, deposition heads, virtual impactors, atomizers, etc.
Clifford, Christopher J. "An Investigation of Physics and Control of Flow Passing a NACA 0015 in Fully-Reversed Condition". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440156651.
Pełny tekst źródłaHoyt, Nathaniel C. "The Performance of Passive Cyclonic Separators in Microgravity". Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1369334515.
Pełny tekst źródłaAvon, Michael A. "Fluid Flow Through Carbon Nanotubes: A New Modeling and Simulation Approach". University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1248615375.
Pełny tekst źródłaJamali, Safa. "Rheology of Colloidal Suspensions: A Computational Study". Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1432054369.
Pełny tekst źródłaStanfield, Scott Alan II. "A SPECTROSCOPIC INVESTIGATION OF A SURFACE-DISCHARGE-MODE, DIELECTRIC BARRIER DISCHARGE". Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1261582116.
Pełny tekst źródłaFirouznia, Mohammadhossein. "The Hydrodynamic Interaction of Two Small Freely-moving Particles in a Couette Flow of a Yield Stress Fluid". Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1502901401749626.
Pełny tekst źródłaArcher, Andrew John. "Statistical mechanics of soft core fluid mixtures". Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288269.
Pełny tekst źródłaMilligan, Ryan Timothy. "DUAL MODE SCRAMJET: A COMPUTATIONAL INVESTIGATION ON COMBUSTOR DESIGN AND OPERATION". Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1251725076.
Pełny tekst źródłaZhang, Shaojie. "Numerical simulation of mechanical interactions between liquid and solid phase in solidification processes". Thesis, Université Paris sciences et lettres, 2020. https://pastel.archives-ouvertes.fr/tel-02897918.
Pełny tekst źródłaControl of macrosegregation phenomena and deformation related defects is the main issue in solidification processes. Numerical modeling provides an answer to industrial needs to master these defects. One of the most critical and essential issues is the concurrent computation of fluid flow in the bulk liquid and stress-strain evolution in the already solidified regions. For this specific purpose, a partitioned solution algorithm is developed to model both ingot casting and continuous casting processes. Liquid flow induced by natural convection or filling step, solidification shrinkage and thermally induced deformation of the solid phase. On the basis of the resulting liquid and solid velocity fields, the transport of chemical species (macrosegregation) is achieved
Potts, John B. III. "Developing and Testing an Anguilliform Robot Swimming with Theoretically High Hydrodynamic Efficiency". ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2103.
Pełny tekst źródłaSmith, Katherine Margaret. "Effects of Submesoscale Turbulence on Reactive Tracers in the Upper Ocean". Thesis, University of Colorado at Boulder, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10623667.
Pełny tekst źródłaIn this dissertation, Large Eddy Simulations (LES) are used to model the coupled turbulence-reactive tracer dynamics within the upper mixed layer of the ocean. Prior work has shown that LES works well over the spatial and time scales relevant to both turbulence and reactive biogeochemistry. Additionally, the code intended for use is able to carry an arbitrary number of tracer equations, allowing for easy expansion of the species reactions. Research in this dissertation includes a study of 15 idealized non-reactive tracers within an evolving large-scale temperature front in order determine and understand the fundamental dynamics underlying turbulence-tracer interaction in the absence of reactions. The focus of this study, in particular, was on understanding the evolution of biogeochemically-relevant, non-reactive tracers in the presence of both large (~5 km) submesoscale eddies and smallscale (~100 m) wave-driven Langmuir turbulence. The 15 tracers studied have different initial, boundary, and source conditions and significant differences are seen in their distributions depending on these conditions. Differences are also seen between regions where submesoscale eddies and small-scale Langmuir turbulence are both present, and in regions with only Langmuir turbulence. A second study focuses on the examination of Langmuir turbulence effects on upper ocean carbonate chemistry. Langmuir mixing time scales are similar to those of chemical reactions, resulting in potentially strong tracer-flow coupling effects. The strength of the Langmuir turbulence is varied, from no wave-driven turbulence (i.e., only shear-driven turbulence), to Langmuir turbulence that is much stronger than that found in typical upper ocean conditions. Three different carbonate chemistry models are also used in this study: time-dependent chemistry, equilibrium chemistry, and no-chemistry (i.e., non-reactive tracers). The third and final study described in this dissertation details the development of a reduced-order biogeochemical model with 17 state equations that can accurately reproduce the Bermuda Atlantic Time-series Study (BATS) ecosystem behavior, but that can also be integrated within high-resolution LES.
Vergnault, Étienne. "Vers une approche multi-échelle pour l'interaction fluide-structure". Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2009. http://tel.archives-ouvertes.fr/tel-00661195.
Pełny tekst źródłaMorris, Seth Henderson. "Quasi-Transient Calculation of Surface Temperatures on a Reusable Booster System with High Angles of Attack". University of Dayton / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1324573899.
Pełny tekst źródłaDucharme, Réjean 1970. "Capillary flow of non-Newtonian fluids". Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23392.
Pełny tekst źródłaWe thus showed that this model was effective only at low pressure and that without adding new aspects to the study of the flow, such as compressibility, we could not obtain any oscillating flow at high pressure. Despite this fact, exact steady-state solutions, as well as a time-dependant solution in the case of very small Reynolds number ($R to$ 0), have been given.
Ongkodjojo, Ong Andojo. "Electrohydrodynamic Microfabricated Ionic Wind Pumps for Electronics Cooling Applications". Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354638816.
Pełny tekst źródłaLeroy, Samuel. "Les forces de surface dynamiques pour l'investigation mécanique des surfaces molles". Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00610528.
Pełny tekst źródłaArratia, Cristobal. "Mécanismes d'instabilité non-modaux dans les écoulements cisaillés avec et sans stratification en densité". Phd thesis, Palaiseau, Ecole polytechnique, 2011. http://www.theses.fr/2011EPXX0084.
Pełny tekst źródłaArratia, Cristobal. "Mécanismes d'instabilité non-modaux dans les écoulements cisaillés avec et sans stratification en densité". Phd thesis, Ecole Polytechnique X, 2011. http://pastel.archives-ouvertes.fr/pastel-00672072.
Pełny tekst źródłaNagai, Toshiki. "Space-time Extended Finite Element Method with Applications to Fluid-structure Interaction Problems". Thesis, University of Colorado at Boulder, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10844711.
Pełny tekst źródłaThis thesis presents a space-time extended finite element method (space-time XFEM) based on the Heaviside enrichment for transient problems with moving interfaces, and its applications to the fluid-structure interaction (FSI) analysis. The Heaviside-enriched XFEM is a promising method to discretize partial differential equations with discontinuities in space. However, significant approximation errors are introduced by time stepping schemes when the interface geometry changes in time. The proposed space-time XFEM applies the finite element discretization and the Heaviside enrichment in both space and time with elements forming a space-time slab. A simple space-time scheme is introduced to integrate the weak form of the governing equations. This scheme considers spatial intersection configuration at multiple temporal integration points. Standard spatial integration techniques can be applied for each spatial configuration. Nitsche's method and the face-oriented ghost-penalty method are extended to the proposed space-time XFEM formulation. The stability, accuracy and flexibility of the space-time XFEM for various interface conditions including moving interfaces are demonstrated with structural and fluid problems. Moreover, the space-time XFEM enables analyzing complex FSI problems using moving interfaces, such as FSI with contact. Two FSI methods using moving interfaces (full-Eulerian FSI and Lagrangian-immersed FSI) are studied. The Lagrangian-immersed FSI method is a mixed formulation of Lagrangian and Eulerian descriptions. As solid and fluid meshes are independently defined, the FSI is computed between non-matching interfaces based on Nitsche's method and projection techniques adopted from computational contact mechanics. The stabilized Lagrange multiplier method is used for contact. Numerical examples of FSI and FSI-contact problems provide insight into the characteristics of the combination of the space-time XFEM and the Lagrangian-immersed FSI method. The proposed combination is a promising method which has the versatility for various multi-physics simulations and the applicability such as optimization.
Clark, Daniel Lee Jr. "Locally Optimized Covariance Kriging for Non-Stationary System Responses". Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464092652.
Pełny tekst źródłaBoyer, Nathan Robert. "The Effects of Viscosity and Three-Dimensionality on Shockwave-Induced Panel Flutter". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu156616766854713.
Pełny tekst źródłaAllen, Ross Roundy Jr. "Variational Principles of Fluid Mechanics and Electromagnetism: Imposition and Neglect of the Lin Constraint". DigitalCommons@USU, 1987. https://digitalcommons.usu.edu/etd/7540.
Pełny tekst źródłaFarhat, Hikmat. "Studies in computational methods for statistical mechanics of fluids". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0026/NQ50157.pdf.
Pełny tekst źródłaGhasemi, Esfahani Ata. "Physics and Control of Flow Over a Thin Airfoil using Nanosecond Pulse DBD Actuators". The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503204430451055.
Pełny tekst źródłaBerthet, Hélène. "Dynamique individuelle et collective de fibres en écoulements microfluidiques confinés". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://pastel.archives-ouvertes.fr/pastel-00765635.
Pełny tekst źródłaDurth, Mélanie. "Dynamiques d'aspirations d'interfaces complexes". Phd thesis, Palaiseau, Ecole polytechnique, 2012. https://pastel.hal.science/docs/00/70/09/99/PDF/thA_se.pdf.
Pełny tekst źródłaInterested in characterizing biological matters of small volumes (bile, cellular aggregates), we develop a capillary aspiration rheometer. We measure the physical properties of the fluid by its deformation and dynamics in the capillary according to the aspiration power. We first test the system with Newtonian fluids. The critical pressure above which the fluid moves, is linked to the initial interface deformation in the capillary and gives a measurement of the surface tension. The displacement of the fluid corresponding to an imposed pressure gives a measurement of the viscosity. Aspirating at constant pressure or at a variable pressure (linearly with time), we extend the domain of viscosities from 10−3 (bile) to 105 Pa. S (cellular aggregates). This range is adequate for biological material. Then we use the system to characterize different complex fluids. We choose the carbopol which stress follows the Herschel-Bulkley law. The critical pressure gives a measurement of the surface tension and minimal stress of carbopol. Aspirated at a pressure linear in time, the carbopol moves at constant velocity and we measure its rheological parameters. Finally, we aspirate cellular aggregates with viscoelastic properties. The aspiration at constant pressure gives a measurement of aggregates viscosity at large times, while the aspiration at variable pressure gives a measurement of the aggregates elasticity
Durth, Mélanie. "Dynamiques d'aspirations d'interfaces complexes". Phd thesis, Ecole Polytechnique X, 2012. http://pastel.archives-ouvertes.fr/pastel-00700999.
Pełny tekst źródłaAl-Awad, Musaed Naser J. "Physico-chemical analysis of shale-drilling fluid interaction and its application in borehole stability studies". Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1368.
Pełny tekst źródłaCapobianco, Vincent J. "Effect of slot height variation on the aerodynamic performance of a circulation control airfoil| A CFD analysis". Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10639011.
Pełny tekst źródłaComputational fluid dynamic (CFD) simulations were conducted on a known low aspect ratio wing design as well as four variant designs incorporating Coanda effect circulation control (CC) for lift generation. The U.S. Navy’s Kestrel code was employed to explore the relation of slot height and lip thickness to maximize lift augmentation. Reynolds Averaged Navier-Stokes calculations were performed at a Reynolds number of 2.1 million over wing configurations with a 1 ft span and chord with top slot flow blowing coefficients of 0, 0.005, 0.05, 0.1, and 0.15 over the angles of attack of 0°, 4°, 8°, 14°, and 18°. The computational results were compared to experimental measurements of slot unblown and blown configurations. General findings include higher lift augmentation ratios of modified designs with similar lip thickness and larger slot gap. Greater lift coefficients were found with larger lip thicknesses and smaller slot heights.
Cox, Christopher. "Development of a High-Order Navier-Stokes Solver Using Flux Reconstruction to Simulate Three-Dimensional Vortex Structures in a Curved Artery Model". Thesis, The George Washington University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10742679.
Pełny tekst źródłaLow-order numerical methods are widespread in academic solvers and ubiquitous in industrial solvers due to their robustness and usability. High-order methods are less robust and more complicated to implement; however, they exhibit low numerical dissipation and have the potential to improve the accuracy of flow simulations at a lower computational cost when compared to low-order methods. This motivates our development of a high-order compact method using Huynh's flux reconstruction scheme for solving unsteady incompressible flow on unstructured grids. We use Chorin's classic artificial compressibility formulation with dual time stepping to solve unsteady flow problems. In 2D, an implicit non-linear lower-upper symmetric Gauss-Seidel scheme with backward Euler discretization is used to efficiently march the solution in pseudo time, while a second-order backward Euler discretization is used to march in physical time. We verify and validate implementation of the high-order method coupled with our implicit time stepping scheme using both steady and unsteady incompressible flow problems. The current implicit time stepping scheme is proven effective in satisfying the divergence-free constraint on the velocity field in the artificial compressibility formulation. The high-order solver is extended to 3D and parallelized using MPI. Due to its simplicity, time marching for 3D problems is done explicitly. The feasibility of using the current implicit time stepping scheme for large scale three-dimensional problems with high-order polynomial basis still remains to be seen.
We directly use the aforementioned numerical solver to simulate pulsatile flow of a Newtonian blood-analog fluid through a rigid 180-degree curved artery model. One of the most physiologically relevant forces within the cardiovascular system is the wall shear stress. This force is important because atherosclerotic regions are strongly correlated with curvature and branching in the human vasculature, where the shear stress is both oscillatory and multidirectional. Also, the combined effect of curvature and pulsatility in cardiovascular flows produces unsteady vortices. The aim of this research as it relates to cardiovascular fluid dynamics is to predict the spatial and temporal evolution of vortical structures generated by secondary flows, as well as to assess the correlation between multiple vortex pairs and wall shear stress. We use a physiologically (pulsatile) relevant flow rate and generate results using both fully developed and uniform entrance conditions, the latter being motivated by the fact that flow upstream of a curved artery may not have sufficient straight entrance length to become fully developed. Under the two pulsatile inflow conditions, we characterize the morphology and evolution of various vortex pairs and their subsequent effect on relevant haemodynamic wall shear stress metrics.
Liu, Chonghui. "A numerical investigation of instability and transition in adverse pressure gradient boundary layers". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0010/NQ36999.pdf.
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