On the anomaly of velocity-pressure decoupling in collocated mesh solutions

The use of various pressure correction algorithms originally developed for fully staggered meshes can yield a velocity-pressure decoupled solution for collocated meshes. The mechanism that causes velocity-pressure decoupling is identified. It is shown that the use of a partial differential equation for the incremental pressure eliminates such a mechanism and yields a velocity-pressure coupled solution. Example flows considered are a three dimensional lid-driven cavity flow and a laminar flow through a 90 deg bend square duct. Numerical results obtained using the collocated mesh are in good agreement with the measured data and other numerical results

A numerical study of chemically reacting flow in nozzles

The space station uses small rocket motors, called thrusters, for orientation control. Because of the lack of viable design tools for small rockets, the initial thruster design was basically a very small version of a large rocket motor. Thrust measurements of the initial design were lower than predicted. To improve predictions it was decided to develop a verison of the RPLUS2D reacting flow code for thruster calculations. RPLUS2D employs an implicit finite volume, lower-upper symmetric successive overrelaxation (LU-SSOR) scheme for solving the complete two-dimensional Navier-Stokes equations and species transport equations in a coupled and very efficient manner. The combustion processes are modeled by a 9-species, 18 step finite-rate chemistry model, and the turbulence is simulated by a Baldwin-Lomax algebraic model. The code is extended to handle multiple subsonic inlet conditions where the total mass flow is governed by conditions calculated at the thruster-throat. Results are shown for a thruster design where the overall mixture ratio is hydrogen rich. A calculation of a large area ratio divergent nozzle is also presented

SSME fuelside preburner two-dimensional analysis

The flow field within the fuelside preburner of the Space Shuttle Main Engine is calculated using a reacting flow code (REACT2D). Inlet and modeling parameters involved in the numerical calculation are systematically varied to establish the sensitivity of the calculated exit temperature profile. It is found that differences in the inlet equivalence ratio have a large effect on the turbine inlet temperature profile. A variety of preburner inlet modeling changes such as inlet turbulence level, modeling the gases as burned, unburned, premixed, or unmixed, are shown to have a smaller effect on the calculated turbine inlet temperature profile. Also, the form of finite differencing used is shown to have an effect on the temperature profile

Thoreau, BLOOD MERIDIAN, and the Myth of the Gunslinger

The gunslinger archetype has appeared in countless western stories and seems almost synonymous with the genre itself. Yet this fixture of the western genre has escaped critical attention and has been conflated with the related, yet separate characters of the cowboy and the outlaw. This archetype finds its metaphorical and mythological roots in the writings of Henry David Thoreau and undergoes an evolution from its first major appearance in Riders of the Purple Sage, through Shane, to Once Upon a Time in the West, finally culminating in the character of the Judge, from Cormac McCarthy’s Blood Meridian. This evolution reveals how the gunslinger is an embodiment of the tension inherent to the wilderness/civilization binary which these texts employ and attempt to surpass. As each of these texts tries to reckon with the tensions the gunslinger embodies, we see that it is the pervasive use of violence that defines the gunslinger’s narrative role

U.S. Health Via Education Analysis

AN ABSTRACT OF THE RESEARCH PAPER OF DANIEL VANOVERBEKE, for the Master of Science degree in AGRIBUSINESS ECONOMICS, presented on AUGUST 18th, 2016 at Southern Illinois University Carbondale. TITLE: U.S. HEALTH VIA EDUCATION ANALYSIS MAJOR PROFESSOR: Dr. Jebaraj Asirvatham Does the level of someone’s education affect their health behaviors such as drinking and smoking? This research aims to examine the relationship between health behaviors & the level of someone’s education with health behaviors as the dependent variable. I aim to model the relationship between health behaviors and the level of education for a 2-year period from 2013-2014. My independent variables in this multiple regression are the U.S. education level, race, age and gender. And, my dependent variables in two separate regressions are the smoking health behavior variable measured in the number of cigarettes measured in the number of cigarettes one smokes in addition to the number of alcoholic drinks someone has had

Country-of-origin and customer purchasing decision

2020 was a year of many challenges in business world from presidential elections, Covid-19 crisis to the moral conflict between Turkey and EU. Those crises differ in nature but led many individuals to question the importance of national industries and supply chain. Country-of-origin effect (to be called COO) argues that some factors are operating at the individual consumer’s psychological level when it comes to purchase a product, or judge someone. Stereotypes have a lot to play in this concept and will be looked at when it comes to understand the roots or this psychological bias. This paper addresses the concept and the roots of the country-of-origin effect, then will look at the concept of customer purchasing decision and how it can be influenced by the COO. This study will be conducted with concerns for the food industry as it has become a hot topic for managers in this sector. In addition to narrowing on the food industry, this paper will try to demonstrate that generational segmentation is to consider when looking at that impact COO has on purchasing decision. To do so we will be launching a questionnaire so to gather data regarding people purchasing behaviour in the light of country-of-origin. This paper found out that even though COO is one of the major factor people consider when buying food related goods, the impact of COO effect differs depending on generations individuals belong to and the region the food-related good originates from.2020 foi um ano de muitos desafios no mundo dos negócios. Essas crises diferem em natureza, mas levaram muitos indivíduos a questionar a importância das indústrias nacionais e da cadeia de suprimentos. O efeito do país de origem (COO) argumenta que alguns fatores estão operando no nível psicológico do consumidor individual quando se trata de comprar um produto ou julgar alguém. Os estereótipos têm muito a jogar neste conceito e serão examinados quando se trata de compreender as raízes ou esse viés psicológico. Este artigo aborda o conceito e as raízes do efeito país de origem e, em seguida, examinará o conceito de decisão de compra do cliente e como ela pode ser influenciada pelo COO. Este estudo será conduzido com preocupações para a indústria de alimentos, uma vez que se tornou um tema quente para os gestores deste setor. Além de estreitar na indústria de alimentos, este artigo tentará demonstrar que a segmentação geracional deve ser considerada quando se olha o impacto que o COO tem na decisão de compra. Para isso, lançaremos um questionário com o objetivo de reunir dados sobre o comportamento de compra das pessoas em função do país de origem. Este artigo descobriu que, embora o COO seja um dos principais fatores que as pessoas consideram ao comprar bens relacionados a alimentos, o impacto do efeito COO difere dependendo da geração a que os indivíduos pertencem e da região de origem do bem relacionado a alimentos

Improved Modeling of Finite-Rate Turbulent Combustion Processes in Research Combustors

The objective of this thesis is to further develop and test a stochastic model of turbulent combustion in recirculating flows. There is a requirement to increase the accuracy of multi-dimensional combustion predictions. As turbulence affects reaction rates, this interaction must be more accurately evaluated. In this work a more physically correct way of handling the interaction of turbulence on combustion is further developed and tested. As turbulence involves randomness, stochastic modeling is used. Averaged values such as temperature and species concentration are found by integrating the probability density function (pdf) over the range of the scalar. The model in this work does not assume the pdf type, but solves for the evolution of the pdf using the Monte Carlo solution technique. The model is further developed by including a more robust reaction solver, by using accurate thermodynamics and by more accurate transport elements. The stochastic method is used with Semi-Implicit Method for Pressure-Linked Equations. The SIMPLE method is used to solve for velocity, pressure, turbulent kinetic energy and dissipation. The pdf solver solves for temperature and species concentration. Thus, the method is partially familiar to combustor engineers. The method is compared to benchmark experimental data and baseline calculations. The baseline method was tested on isothermal flows, evaporating sprays and combusting sprays. Pdf and baseline predictions were performed for three diffusion flames and one premixed flame. The pdf method predicted lower combustion rates than the baseline method in agreement with the data, except for the premixed flame. The baseline and stochastic predictions bounded the experimental data for the premixed flame. The use of a continuous mixing model or relax to mean mixing model had little effect on the prediction of average temperature. Two grids were used in a hydrogen diffusion flame simulation. Grid density did not effect the predictions except for peak temperature and tangential velocity. The hybrid pdf method did take longer and required more memory, but has a theoretical basis to extend to many reaction steps which cannot be said of current turbulent combustion models

A numerical study of the hot gas environment around a STOVL aircraft in ground proximity

The development of Short Takeoff Vertical Landing (STOVL) aircraft has historically been an empirical- and experienced-based technology. A 3-D turbulent flow CFD code was used to calculate the hot gas environment around an STOVL aircraft operating in ground proximity. Preliminary calculations are reported for a typical STOVL aircraft configuration to identify key features of the flow field, and to demonstrate and assess the capability of current 3-D CFD codes to calculate the temperature of the gases ingested at the engine inlet as a function of flow and geometric conditions