The history and trajectory of the human race is inseparable from our innate need to explore the unknown. As human exploration drives boundless new insights into the universe, characterization and accurate modeling methods are required to develop the next generation of exploratory vehicles to map and analyze foreign lands. As such the presented work looks to provide characterization and modeling approaches for unsteady aerodynamic phenomena in the extraterrestrial environments of Mars and Titan. Specifically, unsteady aerodynamic loads including dynamic stall are characterized using high-fidelity numerical experiments to better understand the effects of low Reynolds number and high Mach number flows on the process. Additionally, modeling of unsteady aerodynamic behavior at low Reynolds numbers similar to those observed when designing the Mars ingenuity rotorcraft are developed and extensively evaluated. Lastly, the characterization and multi-fidelity modeling of unsteady aerodynamic effects under Titan atmospheric conditions is conducted for a coaxial rotor system.

This thesis discusses how the hymen is described historically in Swedish sex manuals between 1889-1904, along with descriptions of defloration and chastity. The analysis is based on the assumption that science and gender are social and cultural constructions.  The purpose of this thesis is to examine late nineteenth-early twentieth century’s conceptions of women, sexuality and chastity by discussing this period's descriptions of the hymen in a historical context. This study is concluded by reading and contextualizing sex manuals published in Sweden around the turn of the century. The conclusion of this thesis is that the hymen is not necessarily viewed as a membrane, although every sex manual writer believe that there is some sort of fold, referred to as the hymen, in virgin females' genitals. However, the hymen is not seen as evidence of women's chastity by the authors because of the assumed occurrence of irregularities in this "fold". Under "normal" circumstances, the hymen is believed to break during a woman's first intercourse which is described as painful (and bloody) by the authors of the sex manuals.

Thesis (MScEng)--Stellenbosch University, 2006. / ENGLISH ABSTRACT: The Stellenbosch University Compressor Code (SUCC) has been developed for the purpose of predicting the performance of axial flow compressors by means of axisymmetric inviscid throughflow methods with boundary layer blockage and empirical blade row loss models. This thesis describes the process of the implementation and verification of a number of stall prediction criteria in the SUCC. In addition, it was considered desirable to determine how certain factors influence the accuracy of the stall prediction criteria, namely the nature of the computational grid, the choice of throughflow method used, and the use of a boundary layer blockage model and a radial mixing model. The stall prediction criteria implemented were the di®usion factor limit criterion, de Haller's criterion, Aungier's blade row criterion, Aungier's boundary layer separation criterion, Dunham's, Aungier's and the static-to-static stability criteria. The compressors used as test cases were the Rofanco 3-stage low speed compressor, the NACA 10-stage subsonic compressor, and the NACA 5-stage and 8-stage transonic compressors. Accurate boundary layer blockage modelling was found to be of great importance in the prediction of the onset of stall, and that the matrix throughflow Method provided slightly better accuracy than the streamline curvature method as implemented in the SUCC by the author. The ideal computational grid was found to have many streamlines and a small number of quasi-orthogonals which do not occur inside blade rows. Radial mixing modelling improved the stability of both the matrix throughflow and streamline curvature methods without significantly affecting the accuracy of the stall prediction criteria. De Haller's criterion was over-conservative in estimating the stall line for transonic conditions, but more useful in subsonic conditions. Aungier's blade row criterion provided accurate results on all but the Rofanco compressor. The diffusion factor criterion provided over- optimistic predictions on all machines, but was less inaccurate than de Haller's criterion on the NACA 5-stage transsonic machine near design conditions. The stability methods performed uniformly and equally badly, supporting the claims of other researchers that they are of limited usefulness with throughflow simulations. Aungier's boundary layer separation method failed to predict stall entirely, although this could reflect a shortcoming of the boundary layer blockage model. / AFRIKAANSE OPSOMMING: Die Stellenbosch University Compressor Code (SUCC) is ontwikkel om die prestasie van aksiaalvloei kompressors te voorspel met behulp van aksisimmetriese nie-viskeuse deurvloeimetodes met grenslaagblokkasie en empiriese modelle vir die verliese binne lemrye. Hierdie tesis beskryf die proses waarmee sekere staakvoorspellingsmetodes in die SUCC geïmplementeer en geverifieer is. Dit was ook nodig om die effek van sekere faktore, naamlik die vorm van die berekeningsrooster, die keuse van deurvloeimetode en die gebruik van `n grenslaagblokkasiemodel en radiale vloeivermengingsmodel op die akuraatheid van die staakvoorspellingsmetodes te bepaal. Die staakvoorspellingsmetodes wat geïmplementeer is, is die diffusie faktor beperking metode, de Haller se metode, Aungier se lemrymetode, Aungier se grenslaagmetode en die Dunham, Aungier en die statiese-tot-statiese stabiliteitsmetodes. Die kompressors wat gebruik is om die metodes te toets is die Rofanco 3-stadium lae-spoed kompressor, die NACA 10-stadium subsoniese kompressor en die NACA 5- en 8-stadium transsoniese kompressors. Daar is vasgestel dat akkurate grenslaagblokkasie modelle van groot belang was om `n akkurate aanduiding van die begin van staking te voorspel, en dat, vir die SUCC, die Matriks Deurvloei Metode oor die algemeen 'n bietjie meer akkuraat as die Stroomlyn Kromming Metode is. Daar is ook vasgestel dat die beste berekeningsrooster een is wat baie stroomlyne, en die kleinste moontlike getal quasi-ortogonale het, wat nie binne lemrye geplaas mag word nie. Die numeriese stabiliteit van beide die Matriks Deurvloei en die Stroomlyn Kromming Metode verbeter deur gebruik te maak van radiale vloeivermengingsmodelle, sonder om die akkuraatheid van voorspellings te benadeel. De Haller se metode was oorkonserwatief waar dit gebruik is om die staak-lyn vir transsoniese vloei toestande, maar meer nuttig in die subsoniese vloei gebied. Aungier se lemrymetode het akkurate resultate gelewer vir alle kompressors getoets, behalwe die Rofanco. Die diffusie faktor metode was oor die algemeen minder akuraat as Aungier se metode, maar meer akkuraat as de Haller se metode vir transsoniese toestande. Die stabiliteitsmetodes het almal ewe swak gevaar. Dit stem ooreen met die bevindings van vorige navorsing, wat bewys het dat hierdie metodes nie toepaslik is vir simulasies wat deurvloeimetodes gebruik nie. Aungier se grenslaagmetode het ook baie swak gevaar. Waarskynlik is dit as gevolg van tekortkomings in die grenslaagblokkasiemodel.

Large wind turbine blades, manufactured from fibre reinforced laminated composite materials, are key structural components of wind turbine systems. The demands for efficient and accurate modelling techniques of these composite blades have significantly increased. Over past decades, although complex computational models have been widely developed, more analytically based models are still very much desired to drive the design and optimization of these composite blades forward to be lighter, stronger, efficient and durable. The research work in this thesis aims to develop such more analytically based aerodynamic, structural and aero-elasticity models for large wind turbine blades manufactured from fibre reinforced laminated composite materials. Firstly, an improved blade element momentum (BEM) model has been developed by collectively integrating the individual corrections with the classic BEM model. Compared to other existing models, present BEM model accounts for blade tip and root losses more accurately. For laminar flow, the 3-D cross-flow is negligibly small. In this case, present BEM model with statically measured 2-D aerodynamic coefficients agrees closely to experimental measurements. However, stall delay correction is required for a 3-D rotating blade in stall. A new stall delay model is developed based on Snel s stall delay model. Verifications are performed and discussed for the extensively studied NREL UAE phase-VI test. The predictions of distributive and collective factors, e.g. normalised force coefficients, shaft torque and etc. have been compared to experimental measurements. The present BEM model and stall delay model are original and more accurate than existing models. Secondly, significant deficiency is discovered in the analytical thin-walled closed-section composite beam (TWCSCB) model proposed by Librescu and Vo, which is widely used by others for structural modelling of wind turbine blades. To correct such deficiency, an improved TWCSCB model is developed in a novel manner that is applicable to both single-cell and multi-cell closed sections made of arbitrary composite laminates. The present TWCSCB model has been validated for a variety of geometries and arbitrary laminate layups. The numerical verifications are also performed on a realistic wind turbine blade (NPS-100) for structural analysis. Consistently accurate correlations are found between present TWCSCB model and the ABAQUS finite element (FE) shell model. Finally, the static aero-elasticity model is developed by combining the developed BEM model and TWCSCB model. The interactions are accounted through an iterative process. The numerical applications are carried out on NPS-100 wind turbine. The numerical results show some significant corrections by modelling wind turbine blades with elastic coupling.

Submitted by VINÍCIUS ATHAYDES CANELLO null (vinaocanello@hotmail.com) on 2017-03-16T11:28:58Z No. of bitstreams: 1 Tese Versão Final.pdf: 4376586 bytes, checksum: 13d4cc1c29f43d7c4deb2102a7b48543 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-03-22T16:42:38Z (GMT) No. of bitstreams: 1 canello_va_dr_jabo.pdf: 4376586 bytes, checksum: 13d4cc1c29f43d7c4deb2102a7b48543 (MD5) / Made available in DSpace on 2017-03-22T16:42:38Z (GMT). No. of bitstreams: 1 canello_va_dr_jabo.pdf: 4376586 bytes, checksum: 13d4cc1c29f43d7c4deb2102a7b48543 (MD5) Previous issue date: 2017-02-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O grande desafio do sistema de defesa respiratório é a manutenção dos animais em baias. Pois, devido a diversos fatores, acaba por aumentar as chances do desenvolvimento de afecções respiratórias e a qualidade do material utilizado como cama é fator agravante. Diante disto, três grupos com 5 equinos cada foram submetidos a 45 dias sob o mesmo manejo, sendo dois grupos estabulados com diferentes tipos de cama, um com maravalha esterilizada (ME) e o outro com maravalha não esterilizada (MNE), e o terceiro grupo a pasto (Pasto). Foram realizadas análises do lavado broncoalveolar (LBA) (celularidade e marcadores de estresse oxidativo) e hemograma antes do início do manejo (Basal) e posteriormente a cada 15 dias (M15, M30 e M45). Também foi avaliada a presença de gêneros fúngicos nas amostras de cama, e do feno utilizado na alimentação dos animais. Os hemogramas permaneceram dentro dos valores da normalidade. Os valores obtidos de malondialdeído (MDA) e ácido úrico no LBA não apresentaram diferença entre os momentos e grupos avaliados. A vitamina C no LBA apresentou queda em seus valores em M30. Os três grupos apresentaram queda nas concentrações de glutationa reduzida em M30, tendo havido diferença significativas entre os grupos Pasto e MNE. Os grupos ME e MNE apresentaram queda nos valores de glutationa oxidada em M45, já o grupo Pasto apresentou queda constante a partir de M15, com diferença significativa em relação ao grupo ME em M30. A superóxido dismutase apresentou aumento em M30 no grupo MNE, levando a diferença significativa em relação aos grupos Pasto e ME. A glutationa peroxidase no LBA apresentou queda significativa no grupo ME em M45. Quanto a celularidade do LBA a contagem de células nucleadas totais e eosinófilos não apresentaram diferenças significativas. O grupo ME apresentou elevação nos valores de neutrófilos em M30, levando a diferença significativa em relação aos grupos MNE e Pasto, já o grupo MNE apresentou queda significativa em M45. Os grupos ME e MNE apresentaram queda nos valores de linfócitos no LBA em M30, já o grupo Pasto apresentou queda em M15. O grupo Pasto apresentou aumento dos macrófagos no LBA em M15 e M30. As análises das amostras de cama e feno apresentaram baixas porcentagens de gêneros fúngicos. Grande parte das alterações apresentadas ocorreram em M30, momento em que foram registradas as menores temperaturas e maiores velocidades dos ventos durante todo período experimental, o que possivelmente levou a um desequilíbrio oxidativo pontual, com pequenas variações na celularidade do LBA. Acredita-se que o manejo, as boas condições de higiene e ventilação das baias tenham contribuído para que não houvesse o desenvolvimento de alterações inflamatórias no sistema respiratório dos animais avaliados. Deste modo, podemos concluir que não houve diferenças significativas na manutenção dos animais nos diferentes tipos de cama em relação a resposta inflamatória, estresse oxidativo e desenvolvimento fúngico. / The great challenge of the respiratory defense system is the maintenance of animals in stalls, which due to several factors ends up increasing the chances of development of respiratory diseases. The quality of the material used as bed is an aggravating factor. Three groups of 5 horses were submitted to 45 days under the same management, and two groups were housed with different types of beds, one with sterilized wood shaving (ME) and the other with unsterilized wood shaving (MNE), and the third group was maintened in the pasture. Bronchoalveolar lavage fluid (BALF) and hemoglobin analyzes were performed before baseline and then every 15 days (M15, M30 and M45). It was also evaluated the possible presence of fungal genera in bed samples, and in hay used in animal feeding. The hemograms remained within normal values. The values of malondialdehyde (MDA) and uric acid in BALF showed no difference between the moments and groups evaluated. Vitamin C in BALF showed a decrease in M30 values. The three groups showed a decrease in the concentrations of glutathione reduced in M30, and there were significant differences between the groups pasture and MNE. The ME and MNE groups showed a decrease in the values of oxidized glutathione in M45, whereas the pasture group presented a constant drop from M15, with a significant difference in relation to the ME group in M30. Superoxide dismutase increased in M30 in the MNE group, leading to a significant difference in relation to the pasture and ME groups. Glutathione peroxidase in BALF showed a significant decrease in the ME group in M45. As for the cellularity of BALF, total nucleated and eosinophil counts did not showed significant differences. The ME group presented elevation in neutrophil values in M30, leading to a significant difference in relation to the MNE and pasture groups, whereas the MNE group presented a significant decrease in M45. The ME and MNE groups presented a decrease in lymphocyte values in the BALF in M30, whereas the pasture group presented a decrease in M15. The pasture group presented increase of the macrophages in the BALF in M15 and M30. Bed and hay samples showed low percentages of fungal genera. Most of the alterations presented occurred in M30, at which time the lowest temperatures were recorded throughout the experimental period, possibly leading to a punctual oxidative imbalance, with small variations in BALF cellularity. It is believed that management, good conditions of hygiene and ventilation of the boxes contributed to the no development of inflammatory changes in the respiratory system of the animals evaluated. Thus, we can conclude that there were no significant differences in the maintenance of the animals in the different types of bed in relation to the inflammatory response, oxidative stress and fungal development.

Separated flows about single and multi-element airfoils are featured in many scenarios of practical interest, including: stall of fixed wing aircraft, dynamic stall of rotorcraft blades, and stall of compressor and turbine elements within jet engines. In each case, static and/or dynamic stall can lead to losses in performance. More importantly, modeling and analysis tools for stalled flows are relatively poorly evolved and designs must completely avoid stall due to a lack of understanding. The underlying argument is that advancements are necessary to facilitate understanding of and applications involving static and dynamic stall. The state-of-the-art in modeling stall involves numerical solutions to the governing equations of fluids. These tools often either lack fidelity or are prohibitively expensive. Ever-increasing computational power will likely lead to increased application of numerical solutions. The focus of this thesis is improvements in numerical modeling of stall, the need of which arises from poorly evolved analysis tools and the spread of numerical approaches. Technical barriers have included ensuring unsteady flow field and vorticity reproduction, transition modeling, non-linear effects such as viscosity, and convergence of predictions. Contributions to static and dynamic stall analysis have been been made. A hybrid Reynolds-Averaged Navier-Stokes/Large-Eddy-Simulation turbulence technique was demonstrated to predict the unsteadiness and acoustics within a cavity with accuracy approaching Large-Eddy-Simulation. Practices to model separated flows were developed and applied to stalled airfoils. Convergence was characterized to allow computational resources to be focused only as needed. Techniques were established for estimation of integrated coefficients, onset of stall, and reattachment from unconverged data. Separation and stall onset were governed by turbulent transport, while the location of reattachment depended on the mean flow. Application of these methodologies to oscillating flapped airfoils revealed flow through the gap was dominated by the flap angle for low angles of attack. Lag between the aerodynamic response and input flap scheduling was associated with increased oscillation frequency and airfoil/flap gap size. Massively separated flow structures were also examined.

Delaying stall is always an attractive option in the aerospace industry. The major benefit of delaying stall is increased lift during takeoff and landings as well as during high angle of attack situations. Devices, such as fluidic oscillators, can be integrated into wing flaps to help delay the occurrence of stall by adding energized air to the airflow on the upper surface of the wing flap. The energized air from the oscillator allows the airflow to remain attached to the upper surface of the wing flap. The fluidic oscillator being integrated in this thesis is an active flow control device (AFC). One common method for integrating any device into a wing flap is to remove a section of the flap and mechanically secure the device. A current trend in the aerospace industry is the increased use of fiber-reinforced composites to replace traditional metal components on aircraft. The traditional methods of device integration cause additional complications when applied to composite components as compared to metal components. This thesis proposes an alternative method for integration of the AFC devices, which occurs before the fabrication of wing flaps is completed and they are attached to the aircraft wing. Seven design concepts are created to reduce the complications from using current methods of integration on composite wing flaps. The concepts are based on four design requirements: aerodynamics, manufacturing, maintenance, and structure. Four of the design concepts created are external designs, which place the AFC on the exterior surface of the wing flap in two types of grooved channels. The other three designs place the AFC inside the wing flap skin and are categorized as internal designs. In order for the air exiting the AFC to reach the upper surface of the wing flap, slots are created in the wing flap skin for the internal designs. Within each of the seven design concepts two design variants are created based on foam or ribbed core types. Prototypes were created for all of the external design AFC devices and the side inserted AFC and retaining pieces. Wing flap prototypes were created for the rounded groove straight AFC design, the semi-circular groove with straight AFC, and the side inserted AFC designs. The wing flaps were created using the VARTM process with a vertical layup for the external designs. The rounded groove and semi-circular groove prototypes each went through three generations of prototypes until an acceptable wing flap was created. The side inserted design utilized the lessons learned through each generation of the external design prototypes eliminating the need for multiple generations. The lessons learned through the prototyping process helped refine the designs and determine the ease of manufacturing to be used in the design evaluation. The evaluation of the designs is based on the four design requirements stated above. The assessment of the designs uses two levels of evaluation matrices to determine the most fitting design concept. As a result of the evaluation, all four of the external designs and one of the internal designs are eliminated. The two remaining internal designs' foam core and ribbed variants are compared to establish the final design selection. The vertically inserted AFC foam core design is the most fitting design concept for the integration of an AFC device into a composite wing flap.

This thesis combines measurements with the development of simulation tools for vertical axis wind turbines (VAWT). Numerical models of aerodynamic blade forces are developed and validated against experiments. The studies were made on VAWTs which were operated at open sites. Significant progress within the modeling of aerodynamics of VAWTs has been achieved by the development of new simulation tools and by conducting experimental studies.         An existing dynamic stall model was investigated and further modified for the conditions of the VAWT operation. This model was coupled with a streamtube model and assessed against blade force measurements from a VAWT with curved blades, operated by Sandia National Laboratories. The comparison has shown that the accuracy of the streamtube model has been improved compared to its previous versions. The dynamic stall model was further modified by coupling it with a free vortex model. The new model has become less dependent on empirical constants and has shown an improved accuracy.     Unique blade force measurements on a 12 kW VAWT were conducted. The turbine was operated north of Uppsala. Load cells were used to measure the forces on the turbine. A comprehensive analysis of the measurement accuracy has been performed and the major error sources have been identified. The measured aerodynamic normal force has been presented and analyzed for a wide range of operational conditions including dynamic stall, nominal operation and the region of high flow expansion. The improved vortex model has been validated against the data from the new measurements. The model agrees quite well with the experiments for the regions of nominal operation and high flow expansion. Although it does not reproduce all measurements in great detail, it is suggested that the presented vortex model can be used for preliminary estimations of blade forces due to its high computational speed and reasonable accuracy.

A wind turbine needs to be controlled to ensure its safe and optimal operation, especially during high wind speeds. The most common control objectives are to limit the power and rotational speed of the wind turbine by using pitch control. Aero Energy is a company based in Potchefstroom, South Africa, that has been developing and manufacturing wind turbine blades since 2000. Their most popular product is the AE1kW blades. The blades have a tendency to over-speed in high wind speeds and the cut-in wind speed must be improved. The objective of this study was to develop an active pitch control system for wind turbines. A prototype active pitch control system had to be developed for the AE1kW blades. The objectives of the control system are to protect the wind turbine from over-speeding and to improve start-up performance. An accurate model was firstly developed to predict a wind turbine’s performance with active pitch control. The active pitch control was implemented by means of a two-stage centrifugal governor. The governor uses negative or stalling pitch control. The first linear stage uses a soft spring to provide improved start-up performance. The second non-linear stage uses a hard spring to provide over-speed protection. The governor was manufactured and then tested with the AE1kW blades. The governor achieved both the control objectives of over-speed protection and improved start-up performance. The models were validated by the results. It was established that the two-stage centrifugal governor concept can be implemented on any wind turbine, provided the blades and tower are strong enough to handle the thrust forces associated with negative pitch control. It was recommended that an active pitch control system be developed that uses positive pitching for the over-speed protection, which will eliminate the large thrust forces. Keywords: pitch control, wind turbine, centrifugal governor, over-speed protection, cut-in wind speed, blade element-momentum theory, rotor, generator, stall, feathering. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.

A wind turbine needs to be controlled to ensure its safe and optimal operation, especially during high wind speeds. The most common control objectives are to limit the power and rotational speed of the wind turbine by using pitch control. Aero Energy is a company based in Potchefstroom, South Africa, that has been developing and manufacturing wind turbine blades since 2000. Their most popular product is the AE1kW blades. The blades have a tendency to over-speed in high wind speeds and the cut-in wind speed must be improved. The objective of this study was to develop an active pitch control system for wind turbines. A prototype active pitch control system had to be developed for the AE1kW blades. The objectives of the control system are to protect the wind turbine from over-speeding and to improve start-up performance. An accurate model was firstly developed to predict a wind turbine’s performance with active pitch control. The active pitch control was implemented by means of a two-stage centrifugal governor. The governor uses negative or stalling pitch control. The first linear stage uses a soft spring to provide improved start-up performance. The second non-linear stage uses a hard spring to provide over-speed protection. The governor was manufactured and then tested with the AE1kW blades. The governor achieved both the control objectives of over-speed protection and improved start-up performance. The models were validated by the results. It was established that the two-stage centrifugal governor concept can be implemented on any wind turbine, provided the blades and tower are strong enough to handle the thrust forces associated with negative pitch control. It was recommended that an active pitch control system be developed that uses positive pitching for the over-speed protection, which will eliminate the large thrust forces. Keywords: pitch control, wind turbine, centrifugal governor, over-speed protection, cut-in wind speed, blade element-momentum theory, rotor, generator, stall, feathering. / Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.