Bileaflet mechanical heart valves (BMHVs), though a life-saving tool in treating heart valve disease, are often associated with serious complications, including a high risk of hemolysis, platelet activation, and thromboembolism. One likely cause of this hyper-coagulative state is the nonphysiologic levels of stress experienced by the erythrocytes and platelets flowing through the BMHVs. Research has shown that the combination of shear stress magnitude and exposure time found in the highly transient leakage jet emanating from the b-datum gap during valve closure is sufficient to cause hemolysis and platelet activation. Regions of flow stasis in the valve vicinity may also allow activated platelets to aggregate and form thrombus. This thesis addresses the hypothesis that passive flow control may have the potential to reduce flow-induced thrombogenicity by altering the fluid mechanics of bileaflet mechanical heart valves. To test this hypothesis, a steady model of the regurgitant b-datum line jet was developed and studied. This model served as a test bed for various vortex generator array designs. The fluid mechanics of the b-datum line jet model was investigated with flow visualization and particle image velocimetry. In vitro tests with whole human blood were performed with and without the vortex generators in order to determine how the presence of the passive flow control affected the propensity of the blood to form thrombus. An effort was then made to correlate the fluid mechanics of the jet model with the procoagulant potential results from the blood experiments. The effect of the vortex generators on the fluid mechanics of the valve under physiologic pulsatile conditions was also investigated via flow visualization in the Georgia Tech Left Heart Simulator. By studying a steady model of the regurgitant b-datum line jet, it was found, using an in vitro system with whole human blood, that the presence of vortex generators significantly decreased the blood's propensity for thrombus formation. The potential of applying passive flow control to cardiovascular hardware in order to mitigate the injurious effects of shear-induced platelet activation is thus demonstrated. The investigation into the effect of vortex generators on the fluid mechanics of the b-datum line jet showed that the jet oscillated aperiodically and that the effect of the applied flow control was played out at both the scale of the chamber (large-scale) and on the scale of the vortex generator fins (small-scale). On the large scale, the presence of vortex generators appeared to decrease the magnitude or frequency of jet oscillation, thereby stabilizing the jet. After removing the effect of the large-scale oscillations via phase averaging, the effect of the vortex generators on the small scale was examined. On the small scale, the jet without flow control was found to have higher levels of velocity RMS, particularly on the jet periphery, and higher levels of Reynolds shear stress. It is proposed that the vortex generators effect this change by generating vorticity in the plane of the jet. This vorticity is theorized to stabilize the jet, delaying roll-up of the jet shear layer which occurs via the Kelvin-Helmholtz instability. The method by which the vortex generators acted on the fluid mechanics of the steady jet system to decrease the blood's procoagulant potential was investigated via flow visualization and DPIV. The results from these studies implicate two possible mechanisms by which the vortex generators may act. First, the peak turbulent shear stresses in the jet were reduced by 10-20% with the application of vortex generators. Even if only a few platelets were activated in each passage through the valve, the cumulative effect of this difference in peak stresses after many passes would be greatly magnified. Thus, this reduction in turbulent shear stresses may be sufficient to explain the change seen in the blood's procoagulant potential with the application of passive flow control. It is suspected, though, that the second mechanism is dominant. The flow fields revealed that the presence of the vortex generators delayed or prevented the roll-up of the Kelvin-Helmholtz instability in the b-datum jet's shear layers into discrete vortices. By doing so, it is thought that opportunities for the interaction of activated and unactivated platelets entrained in these vortices were prevented, thereby inhibiting further propagation of the coagulation cascade. Even if the rate at which platelets were activated was similar for cases with and without flow control, it seems that the flow fields experienced by the platelets subsequent to activation can determine the level of procoagulant potential. Under the steady conditions observed in this experiment, the jet influenced by vortex generators was thus shown to induce significantly lower levels of procoagulant potential.

When sharing data across multiple sites, service applications should not be trusted automatically. Services that are suspected of faulty, erroneous, or malicious behaviors, or that run on systems that may be compromised, should not be able to gain access to protected data or entrusted with the same data access rights as others. This thesis proposes a context flow model that controls the information flow in a distributed system. Each service application along with its surrounding context in a distributed system is treated as a controllable principal. This thesis defines a trust-based access control model that controls the information exchange between these principals. An online monitoring framework is used to evaluate the trustworthiness of the service applications and the underlining systems. An external communication interception runtime framework enforces trust-based access control transparently for the entire system.

The unsteady interaction between trailing edge aerodynamic flow control and airfoil motion in pitch and plunge is investigated in wind tunnel experiments using a two degree-of-freedom traverse which enables application of time-dependent external torque and forces by servo motors. The global aerodynamic forces and moments are regulated by controlling vorticity generation and accumulation near the trailing edge of the airfoil using hybrid synthetic jet actuators. The dynamic coupling between the actuation and the time-dependent flow field is characterized using simultaneous force and particle image velocimetry (PIV) measurements that are taken phase-locked to the commanded actuation waveform. The effect of the unsteady motion on the model-embedded flow control is assessed in both trajectory tracking and disturbance rejection maneuvers. The time-varying aerodynamic lift and pitching moment are estimated from a PIV wake survey using a reduced order model based on classical unsteady aerodynamic theory. These measurements suggest that the entire flow over the airfoil readjusts within 2-3 convective time scales, which is about two orders of magnitude shorter than the characteristic time associated with the controlled maneuver of the wind tunnel model. This illustrates that flow-control actuation can be typically effected on time scales that are commensurate with the flow's convective time scale, and that the maneuver response is primarily limited by the inertia of the platform.

Information security is of utmost concern in a multiuser environment. The importance of security is felt much more with the widespread use of distributed database. Information is by itself a critical resource of an enterprise and thus the successful operation of an enterprise demands that data be made accessible only by authorized users and that the data be made to reflect the state of the enterprise. Since many databases are online, accessed by multiple users concurrently, special mechanisms are needed to insure integrity and security of relevant information, This thesis describes a model for computer database security that supports a wide variety of security policies. The terms security policies and security mechanism are presented in Chapter I. The interrelated topics of security and integrity are discussed in some detail. The importance and means of insuring security of information is also presented in this chapter. In Chapter 2, the work done In the field of Computer Security and related topic has been presented. In general computer security models could be classified broadly under the two categories. (1) Models based on Access Control Matrix and (2) Models based on Information Flow Control. The development of the models baaed on the above two schemes as also the policies supported by some of the schemes are presented in this chapter. A brief description of the work carried out in database security as aim the definition of related terns are given in Chapter 3. The interrelationship between the operating system security and database security is also presented in this chapter. In general the database security mechanism depends on the existing operating system. The database security mechanism are thus only as strong as the underlying operating system on which it is developed. The various schemes used for implementing database security such as access controller and capability lists are described in this chapter. In Chapter 4, a model for database security has been described. The model provides for: (a) Delegation of access rights by a user and (b) Revocation of access rights previously granted by a user. In addition, algorithms for enforcing context dependent and content dependent rules are provided in this cheer. The context-dependent rules are stored in the form of elements of a bit matrix. Context-dependent rules could then be enforced by suitably manipulating the bit matrix and interpreting the value of me elements of the matrix, The major advantage of representing the rules using bit matrices is that the matrix itself could be maintalnet3 in main memory. The time taken to examine if a user is authorized to access an object is drastically reduced because of the reduced time required to inspect main memory. The method presented in this chapter, in addition to reducing the time requirement for enforcing security also presents a method for enforcing decentralized authorization control, a facility that is useful in a distributed database environment. Chapter 5 describes a simulation method that is useful for comparing the various security schemes. The tasks involved in the simulation are – 1. Creation of an arrival (job). 2. Placing the incoming job either in the wait queue or in the run state depending on the type of access needed for: the object. 3. Checking that the user on whose behalf the job is being executed is authorized to access the object in the mode requested. 4. Checking for the successful completion of the job and termination of the job. 5. Collection of important parameters such as number of jobs processed, average connect time. Simulation was carried out for timing both the access controller scheme and bit matrix scheme, The results of the simulation run bear the fact that the bit matrix scheme provides a faster method Six types of access were assumed to be permissible, three of the access types requiring shared lock and the rest requiring exclusive locks on the objects concerned, In addition the only type of operation allowed was assumed to be for accessing the objects. It is be noted that the time taken to check for security violation is but one of the factors for rating the security system. In general, various other factors such as cost of implementing the security system, the flexibility that offers enforcing security policies also have to be taken into account while comparing the security systems. Finally, in Chapter 6, a comparison of the security schemes are made. In conclusion the bit matrix approach is seen to provide the following features. (a) The time required to check if an access request should be honoured is very small. (b) The time required to find a11 users accessing an object viz, accountability is quite small. (c) The time required to find all objects accessible by a user is also quite small. (dl The scheme supports both decentralized and centralized authorization control. (e) Mechanism for enforcing delegation of access rights and revocation of access rights could be built in easily. ( f ) The scheme supports content-dependent, context-dependent controls and also provides a means for enforcing history-dependent control. Finally, some recommendations for further study in the field of Computer Database Security are presented.

A model has been developed which simulates a system consisting of a horizontal and vertical ground-coupled heat exchanger connected in parallel to the same heat pump. The model was used in computer simulations to investigate how the annual minimum and mean fluid temperatures at the heat pump varied as several parameters of the combined system were changed. A comparison was also made between different control settings for fluid flow rate distribution between the two exchangers. For the case when the flow rate distribution was not controlled, the effect of viscosity differences between a colder and warmer exchanger was investigated. The short term effects of letting the vertical heat source rest during the warm summer months was then tested. Lastly, the results of the model was compared to a simple 'rule of thumb' that have been used in the industry for this kind of combined system. The results show that using a combined system might not always result in increased performance, if the previously existing exchanger is a vertical ground-coupled heat exchanger. The effects of viscosity differences on the flow distribution seems to be negligible, especially for high net flows. Controlling the fluid flow rates seems to only be worth the effort if the the pipe lengths of the two combined exchangers differ heavily. Letting the vertical ground-coupled heat exchanger rest during summer was shown to in some cases yield an increased short-term performance in addition to the already known positive long term effects. The rule of thumb was shown to recommend smaller dimensions for combination systems than the more realistic analytical model.

Acoustic noise pollution is an environmental aggressor in everyday life. Aero- dynamically generated noise annoys and was linked with health issues. It may be caused by high-speed turbulent free flows (e.g. aircraft jet exhausts), by airflow interacting with solid surfaces (e.g. fan noise, wind turbine noise), or it may arise within a confined flow environment (e.g. air ventilation systems, refrigeration systems). Hence, reducing the acoustic noise levels would result in a better life quality, where a systematic approach to decrease the acoustic noise radiation is required to guarantee optimal results. Computational predic- tion methods able to provide all the required flow quantities with the desired temporal and spatial resolutions are perfectly suited in such application areas, when supplementing restricted experimental investigations. This thesis focuses on the use of numerical methodologies in compressible flow applications to understand aerodynamically noise generation mechanisms and to assess technologies used to suppress it. Robust and fast steady-state Reynolds Averaged Navier-Stokes (RANS) based formulations are employed for the optimal design process, while the high fidelity Large Eddy Simulation (LES) approach is utilized to reveal the detailed flow physics and to investigate the acoustic noise production mechanisms. The employment of fast methods on a wide range of cases represents a brute-force strategy used to scrutinize the optimization parameter space and to provide general behavioral trends. This in combination with accurate simulations performed for particular condi- tions of interest becomes a very powerful approach. Advance post-processing techniques (i.e. Proper Orthogonal Decomposition and Dynamic Mode Decomposition) have been employed to analyze the intricate, highly turbulent flows. The impact of using fluidic injection inside a convergent-divergent nozzle for acoustic noise suppression is analyzed, first using steady-state RANS simulations. More than 250 cases are investigated for the optimal injection location and angle, amount of injected flow and operating conditions. Based on a-priori established criteria, a few optimal candidate solutions are detected from which one geometrical configuration is selected for being thoroughly investigated by using detailed LES calculations. This allows analyzing the unsteady shock pattern movement and the flow structures resulting with fluidic injec- tion. When investigating external fluidic injection configurations, some lead to a high amplitude shock associated noise, so-called screech tones. Such unsteady phenomena can be captured and explained only by using unsteady simulations. Another complex flow scenario demonstrated using LES is that of a high ve- locity jet ejected into a confined convergent-divergent ejector (i.e. a jet pump). The standing wave pattern developed in the confined channel and captured by LES, significantly alters the acoustic noise production. Steady-state methods failed to predict such events. The unsteady highly resolved simulations proved to be essential for analyzing flow and acoustics phenomena in complex problems. This becomes a very powerful approach when is used together with steady-state, low time-consuming formulations and when complemented with experimental measurements. / <p>QC 20141202</p>

An aluminum NACA 0018 airfoil testbed was constructed with 95 static pressure taps and 25 embedded microphones to enable novel time-resolved measurements of surface pressure. The main objective of this investigation is to utilize time-resolved surface pressure measurements to estimate salient flow characteristics in the separated flow region over the upper surface of an airfoil. The flow development over the airfoil was examined using hot wire anemometry and mean surface pressure for a range of Reynolds numbers from 80x103 to 200x103 and angles of attack from 0° to 18°. For these parameters, laminar boundary layer separation takes place on the upper surface and two flow regimes occur: (i) separation is followed by flow reattachment, so that a separation bubble forms and (ii) separation occurs without subsequent reattachment. Measurements of velocity and mean surface pressure were used to characterize the separated flow region and its effect on airfoil performance using the lift coefficient. In addition, the transition process and the evolution of disturbances were examined. The lift curve characteristics were found to be linked to the rate of change of the separation, transition, and reattachment locations with the angle of attack. For both flow regimes, transition was observed in the separated shear layer. Specifically, the amplification of disturbances within a band of frequencies in the separated shear layer resulted in laminar to turbulent transition. Validation of time-resolved surface pressure measurements was performed for Rec = 100x103 at α = 8° and α = 12°, corresponding to regimes of flow separation with and without reattachment, respectively. A comparative analysis of simultaneous velocity and time-resolved surface pressure measurements showed that the characteristics and development of velocity fluctuations associated with disturbances in the separated shear layer can be extracted from time-resolved surface pressure measurements. Specifically, within the separated flow region, the amplitude of periodic oscillations in the surface pressure signal associated with disturbances in the separated shear layer grew in the streamwise direction. In addition, the frequency at the spectral peak of the amplified disturbances in the separated shear layer was identified. Based on the results of the validation analysis, time-resolved surface pressure measurement analysis techniques were applied for a Reynolds number range from 60x103 to 130x103 and angles of attack from 6° to 16°. Within the separated flow region, the streamwise growth of surface pressure fluctuations is distinctly different depending on the flow regime. Specifically, within the separation bubble, the RMS surface pressure fluctuations increase in the streamwise direction and reach a peak just upstream of the reattachment location. The observed trend is in agreement with that observed for other separating-reattaching flows on geometries such as the forward and backward facing step and splitter plate with fence. In contrast to the separation bubble formation, when the separated shear layer fails to reattach to the airfoil surface, RMS surface pressure fluctuations increase in the streamwise direction with no maximum and the amplitude is significantly lower than those observed in the separation bubble. Surface pressure signals were further examined to identify the frequency, convective velocity, and spanwise uniformity of disturbances in the separated shear layer. Specifically, for both flow regimes, the fundamental frequency and corresponding Strouhal number exhibit a power-law dependency on the Reynolds number. Based on the available data for which velocity measurements were obtained in the separated flow region, the convective velocity matched the mean velocity at the wall-normal distance corresponding to the maximum turbulence intensity. A distinct increase in the convective velocity of disturbances in the separated shear layer was found when the airfoil was stalled in comparison to that found in the separation bubble. From statistical analysis of surface pressure signals in the spanwise direction, it was found that disturbances are strongly two-dimensional in the laminar portion of the separated shear layer and become three-dimensional through the transition process.

In the military arena there is an increase in demand for Low Observable (LO) flight vehicles. This drive for low observability imposes limits on Leading Edge (LE) sweep angles and prohibits the use of a tailplane/fin resulting in unconventional configurations; a typical example of which are Unmanned Combat Aerial Vehicles (UCAVs). This class of aircraft poses stability and control problems due to the early onset of flow separation. The focus of this project is on the on the use of Tangential Leading Edge Blowing (TLEB) as a means of separation suppression on such vehicles. This project is unique in that the TLEB slot is positioned on the wing lower surface facing the oncoming freestream. Also, the model in this project is representative of the outboard panel of a UCAV wing, a geometry on which TLEB has not been explored in the past. A swept wing model (LE sweep = 47 degrees, AR = 3) was designed. The model has a TLEB nozzle with a slot on the lower surface at approx. 1% yawed chord that spans 0.58 m (approx. 70% LE length). Baseline wing characteristics were obtained with the full slot exposed. The wing showed a variation in pitch between CL = 0 and 0.6 which from oil flow visualisation is believed to be due to laminar separation. At CL = 0.6 there is a positive pitch break which flow visualisation suggests is due to the occurrence of a LE vortex. Sensitivity studies for slot configuration, Re number and transition fixing were carried out. The blowing rates 0.0025, 0.005, 0.025, 0.05 were tested for two slot lengths; one full span (0.58 m) and another third span positioned at the midpoint of the full slot. All blowing rates show some suppression of the LE vortex and therefore reduction in severity of the pitch break at CL = 0.6. High blowing rates produce a negative shift in CM, which CFD suggests is due to a large amount of suction produced on the lower wing surface adjacent to the slot exit. This means the available trim power is less than for the lower blowing rates. Wool tuft results for high blowing rates from the middle slot show an increase in streamwise flow at the TE suggesting TLEB is capable of improving the effectiveness of TE devices. The effectiveness of TLEB at low blowing rates has been shown to be high compared to that found in literature. A 1st order analysis of the impact of TLEB on a full scale system shows realistic options.

Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-07T06:00:13Z (GMT). No. of bitstreams: 1 Borgonovo_Marina_M.pdf: 1886438 bytes, checksum: 4d2f8ab684a1762ddb05ea2896b81b03 (MD5) Previous issue date: 2006 / Resumo: Este trabalho apresenta um novo algoritmo de Controle de Admissão de Chamadas (CAC) que funciona em conjunto com o Controle de Fluxo na interface aérea com o objetivo de proporcionar a diferenciação de classes de modo e?ciente. Assim, o mecanismo proposto busca melhorar a utilização da interface aérea a partir da introdução de uma estratégia de bloqueio gradual onde os usuários de menor prioridade têm suas taxas de transmissão reduzidas ao invés de serem diretamente eliminados do sistema. O parâmetro de decisão do CAC e do Controle de Fluxo é a banda efetiva disponível na interface aérea. O algoritmo toma medidas próativas de acordo com a carga do sistema visando manter a qualidade requerida por cada classe. Isto é conseguido com a utilização de três limiares de decisão para os algoritmos de CAC e controle de ?uxo, sendo que o sistema toma medidas distintas de acordo com o limiar . Três classes foram consideradas: Premium, Ouro e Prata. O algoritmo foi implementado e simulado no software MatLab. Os resultados mostram que a diferenciação de classes é atingida e os níveis de bloqueio são iguais ou menores que no caso onde utilizase apenas um limiar e sem diferenciação de classes / Abstract: The current work presents a new multithreshold CAC algorithm that works along with a ?ow control mechanism in order to offer full class differentiation. Furthermore the proposed scheme aims to improve the air interface utilization by introducing a softblocking strategy where the lower classes users have their transmission rates truncated before completely stopped. The decision parameter for the CAC and Flow control is the Air Interface Effective Bandwidth. The algorithm takes proactive steps according to the system load in order to keep the quality level required by each class. That is done by introducing three thresholds for the CAC and Flow Control algorithms, in this way the system takes different actions according to the load it is experiencing in each decision moment. Three classes were considered, premium, gold, and silver. The proposed mechanism was implemented in simulated in the Matlab software. Results show that the class differentiation is achieved and the blocking rates remain on the same levels than in the one threshold case / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Recently, the wavy leading edge airfoils, inspired by the humpback whale´s flipper, have been investigated, as flow control mechanisms, at low Reynolds numbers in order to improve aerodynamic performance in this particular flow regime. The overall aim of this work is to investigate the airfoil geometric effects on wavy leading edge phenomena in the low Reynolds number regime. Experimental investigations were carried out correlating force measurements with mini-tuft and oil visualizations in order to understand the airfoil thickness effects on wavy leading edge phenomena. Three sets of airfoil thickness were tested (NACA 0012, NACA 0020 and NACA 0030), each set consisting of smooth plus three wavy configurations (A=0.11c, ?=0.40c; A=0.03c, ?=0.40c and A=0.03c, ?=0.11c); Reynolds number was varied between 50,000 and 290,000. The results present many findings that were not possible in previous studies due the fact that these investigations were constrained to specific geometries and/or flow conditions. At higher Reynolds number, the decrease in airfoil thickness leads the airfoils to leading edge stall characteristics causing the lowest aerodynamic deterioration for the thinnest wavy airfoil as compared to smooth configuration in the pre-stall regime. In addition, the results show impressive tubercle performance in the lowest Reynolds number. For any tubercle geometry and airfoil thickness, the wavy leading edge airfoils present higher maximum lift values as compared to smooth configurations showing an unprecedented increase in performance for a full-span model tested in the literature. The flow visualizations present two flow mechanisms triggered by secondary flow: three-dimensional laminar separation bubbles and vortical structures. Regarding three-dimensional laminar bubbles, the results confirm some of the few previous experimental and numerical studies, and presents for the first time these structures as a very efficient flow control mechanism in the post-stall regime justifying the impressive increase in maximum lift in the lowest Reynolds number. Besides that, two characteristics of laminar bubbles, \"tipped-bubbles\" and \"elongated-bubbles\", are identified with different effects in the pre-stall regime. This thesis presents higher tubercle performance for thinner airfoils (NACA 0012) and/or lower Reynolds number conditions (Re=50,000) showing clearly that an optimum performance lead the \"tubercles\" to operate under conditions of leading edge flow separation conditions. Therefore, a design space for tubercles conducted to leading edge stall characteristics confirming the hypothesis of Stanway (2008) eight years before. / Recentemente, aerofólios com bordo de ataque ondulados, inspirados na nadadeira da baleia jubarte, tem sido investigados como mecanismo de controle de escoamento para baixo número de Reynolds com a finalidade de se aumentar o desempenho aerodinâmico neste específico regime de escoamento. O objetivo geral deste trabalho é investigar os efeitos geométricos do aerofólio nos fenômenos do bordo de ataque ondulado na condição de baixo número de Reynolds. Investigações experimentais foram realizadas correlacionando medições de forças com visualizações de lã e óleo a fim de compreender os efeitos da espessura do aerofólio sobre os fenômenos de bordo de ataque ondulado. Três conjuntos de espessura de aerofólios foram testados (NACA 0012, NACA 0020 e NACA 0030) na faixa de número de Reynolds entre 50,000 e 290,000, onde cada conjunto tem um aerofólio liso e três ondulados (A = 0.11c, ? = 0.40c; A = 0.03c, ? = 0.40c e A = 0.03c, 0.11c ? =0.11c). O dados experimentais mostram importantes resultados que não foram possíveis em estudos anteriores devido às investigações serem restritas à geometria ou/e condição de escoamento específicas. O resultados de medida de força mostram que a diminuição da espessura do aerofólio conduz às características de separação de escoamento de bordo de ataque que causam menor deterioração aerodinâmica nos aerofólios ondulados finos quando comparados aos lisos no regime de pré-stall. Além disso, os resultados mostram um desempenho destacado do bordo de ataque ondulado para condição de menor número de Reynolds. Em quaisquer espessuras de aerofólio, os bordos ondulados apresentam valores de sustentação máxima maiores quando comparado aos aerofólios lisos mostrando assim resultado inédito na literatura para modelos ondulados bi-dimensionais. As visualizações de óleo evidenciaram dois mecanismos de controle de escoamento desencadeadas pelo escoamento secundário: bolhas de separação laminar tridimensionais e estruturas vorticais. Os resultados confirmam alguns poucos estudos experimentais e numéricos anteriores relacionadas com bolhas tridimensionais, e apresenta pela primeira vez estas estruturas como um mecanismo muito eficiente de controle de escoamento em regime de pós-stall justificando o aumento de máxima sustentação para o menor número de Reynolds. Adicionalmente, foram identificadas duas estruturas de bolhas tridimensionais nomeados aqui como \"bolhas com pontas\" e \"bolhas alongadas\" que causam distintos efeitos no regime de pré-stall. Esta tese apresenta como resultado maior desempenho para aerofólios ondulados com menor espessura (NACA 0012) e/ou para condições de menor número de Reynolds (Re=50,000)mostrando claramente que estas características levam as ondulações a operarem em condições de stall de bordo de ataque assim tendo um desempenho superior. Portanto, um espaço de projeto para tubérculos conduz às características de stall de bordo de ataque confirmando a suposição de Stanway (2008) oitos anos antes.