A literature survey was conducted to determine the factors which affect aerodynamic drag of spheres. Graphs are presented which show the effect of each variable where such information was available. Equipment was designed and built for the purpose of studying the effects of acceleration on the aerodynamic drag of spheres. Special emphasis was placed on the measurement and control of each of the other variables which can affect the drag. Tests were conducted using large spheres in air and water to show that the method presented can produce a valid determination of the drag coefficients. The numerical values of the measured data cannot be considered accurate because of known discrepancies in the test equipment. Information is also presented on the use of this equipment for tests with small diameter spheres. Recommendations are made for further testing on the aerodynamic drag of spheres and for needed changes and additions to the test equipment.

The object of this investigation was to obtain a reliable technique for finding the drag coefficient for a sphere falling at a non-constant velocity through air. And then to apply this technique to the data collected by R. G. Lunnon in 1925^(4)*.

Throughout literature, one finds where numerous methodologies and models have been developed to predict the effect of surface roughness on a flat surface. Many of the models utilize a drag coefficient as one of the necessary parameters. In urban settings with groups of buildings, the drag coefficient on an individual obstacle would be determined by parameters like wind direction and the relative positioning of a building, in addition to Reynolds number and shape. Computational experiments were performed to simulate the fluid flow around a single row and two rows of “cube” obstacles. Based on dimensional analysis, the drag coefficient was formulated as a function of four input variables. The effect of these input variables on the drag coefficient was individually studied. Finally, using the central composite design method and the numerically obtained experiment data, a second-order mathematical model was devised for the drag coefficient as a function of the four input variables.

A procedure for generating and using polynomial approximations to the range or to the cruise drag components in terms of 29 design variables for the High Speed Civil Transport (HSCT) configuration and performance design is presented. Response surface model methodology is used to fit quadratic polynomials to data gathered from a series of numerical analyses of different HSCT designs. Several techniques are employed to minimize the number of required analyses and to maintain accuracy. Approximate analysis techniques are used to find regions of the design space where reasonable HSCT designs could occur and response surface models are built using higher fidelity analysis results of the designs in this "reasonable" region. Regression analysis and analysis of variance are then used to reduce the number of polynomial terms in the response surface model functions. Optimizations of the HSCT are then carried out both with and without the response surface models, and the effect of the use of the response surface models is discussed. Results of the work showed that considerable reduction of the amount of numerical noise in optimization is achieved with response surface models and the convergence rate was slightly improved. Careful attention was required to keep the accuracy of the models at an acceptable level. NOTE: (07/2012) An updated copy of this ETD was added after there were patron reports of problems with the file. / Master of Science

Design of small uninhabited aerial vehicles is hampered by the relatively sparse database available for aerodynamic properties of basic shapes at low Reynolds number (Re). As a step towards remedying this situation, an experimental investigation of the influence of aspect ratio on the drag of circular cylinders at low Re has been conducted. The experiment itself faced the difficulty of measuring the small forces associated with low Re. A novel solution to this problem has been developed and applied in the Patterson Hall low speed wind tunnel at Mississippi State University. Using this method the drag characteristics of cylinders with aspect ratios varying from 16 down to 1 over a Reynolds number range from 10^5 down to 10^4 have been measured. This presentation will discuss the existing database, the present experimental method and the results that have been obtained.

No description available.

No description available.

The design of pathogen biosensors may soon incorporate beads having a nanoscale diameter, thus making the drag force on a nanoscale sphere an important engineering problem. Flows at this small of a scale begin to appear "grainy" and may not always behave as a continuous fluid. Molecular dynamics provides an approach to determine drag forces in those nanoscale flows which cannot be described with continuum (Navier-Stokes) theory. This thesis uses a molecular dynamics approach to find the drag forces acting on a sphere and a wall under several different conditions. The results are compared with approximations from a Navier-Stokes treatment and found to be within an order of magnitude despite the uncertainties involved in both the atomic interactions of the molecular dynamics simulation and the appropriate boundary conditions in the Navier-Stokes solution. / Master of Science

nÃo hà / A prÃtica drag queen diz respeito a um processo de adequaÃÃo que desloca a aparÃncia corriqueira de uma pessoa para uma outra que pode transitar entre gÃneros (masculino, feminino, polimorfo, diversos) e espÃcies (humano e animal, como à o caso de drags que se apresentam como animais e atà alienÃgenas). O presente trabalho tem por objetivo observar e participar dessa prÃtica na cidade de Fortaleza â CE com intuito de absorver seus processos de criaÃÃo, adaptaÃÃo, montagem e desmontagem. Entender as mutaÃÃes as quais essa prÃtica està sujeita, as influÃncias externas e a capacidade de adaptaÃÃo das drag queens estudadas. Usar lentes analÃticas que possibilitem enxergar as prÃticas atravÃs de uma epistemologia da performance que leve em consideraÃÃo a decolonizaÃÃo do pensamento e a apreensÃo crÃtica da tradiÃÃo cientÃfica europeia. O estudo se configura por meio de uma experiÃncia etnogrÃfica embasada no exercÃcio da descriÃÃo densa e de entrevistas pontuais. Os registros foram feitos mediante diÃrio de campo, fotografias, vÃdeos e gravador de voz. Concluiu-se que a prÃtica drag queen na cidade de Fortaleza â CE passou e passa por mudanÃas constantes no que diz respeito à tradiÃÃo e ao surgimento de novas formas de fazer drag. Formas essas impactadas pelo reality show americano RuPaulâs Drag Race e sua tendÃncia de transformaÃÃo da drag queen em um produto passÃvel de ser comercializado mundialmente atravÃs da TV. Observou-se ainda que, ademais da forte influÃncia trazida por esse reality show, o contexto local tem se mostrado resistente Ãs tentativas de suplantaÃÃo da tradiÃÃo, tendo como elementos de resistÃncia o batecabelo e o dialeto yorubà que se contrapÃem à forÃa histÃrica de opressÃo conhecida como colonizaÃÃo. / A prÃtica drag queen diz respeito a um processo de adequaÃÃo que desloca a aparÃncia corriqueira de uma pessoa para uma outra que pode transitar entre gÃneros (masculino, feminino, polimorfo, diversos) e espÃcies (humano e animal, como à o caso de drags que se apresentam como animais e atà alienÃgenas). O presente trabalho tem por objetivo observar e participar dessa prÃtica na cidade de Fortaleza â CE com intuito de absorver seus processos de criaÃÃo, adaptaÃÃo, montagem e desmontagem. Entender as mutaÃÃes as quais essa prÃtica està sujeita, as influÃncias externas e a capacidade de adaptaÃÃo das drag queens estudadas. Usar lentes analÃticas que possibilitem enxergar as prÃticas atravÃs de uma epistemologia da performance que leve em consideraÃÃo a decolonizaÃÃo do pensamento e a apreensÃo crÃtica da tradiÃÃo cientÃfica europeia. O estudo se configura por meio de uma experiÃncia etnogrÃfica embasada no exercÃcio da descriÃÃo densa e de entrevistas pontuais. Os registros foram feitos mediante diÃrio de campo, fotografias, vÃdeos e gravador de voz. Concluiu-se que a prÃtica drag queen na cidade de Fortaleza â CE passou e passa por mudanÃas constantes no que diz respeito à tradiÃÃo e ao surgimento de novas formas de fazer drag. Formas essas impactadas pelo reality show americano RuPaulâs Drag Race e sua tendÃncia de transformaÃÃo da drag queen em um produto passÃvel de ser comercializado mundialmente atravÃs da TV. Observou-se ainda que, ademais da forte influÃncia trazida por esse reality show, o contexto local tem se mostrado resistente Ãs tentativas de suplantaÃÃo da tradiÃÃo, tendo como elementos de resistÃncia o batecabelo e o dialeto yorubà que se contrapÃem à forÃa histÃrica de opressÃo conhecida como colonizaÃÃo.

For over the thirty years, drag performance has been examined for its utility to subvert or reinforce traditional gender roles. Many of these examinations have focused on performances that emphasize subversion and separated drag into two categories: the progressive drag that subverts, and the regressive drag that reinforces. While this approach has provided a wealth of understanding about drag performance and gender roles, drag can be examined without separating its subverting/reinforcing aspects. If drag is seen as the consideration of a given gender performing the not given gender, then another consideration can be made to the subverting performing the reinforcing. This new consideration, referred to here as the divine, can provide new utility for drag performance and its role in understanding gender.