From the beginning of the history of flight, inspiration has been drawn from nature. Evolution has spent millions of years optimizing creatures that rely on flight as their means of locomotion. Today, aerial vehicles are very different to those from the time of the Wright brothers. One kind of vehicle that stands to benefit in mimicking nature is the drone, particularly smaller drones. Commonly used today by militaries, industry and civilians, drones are increasingly affordable while also decreasing in size thanks to advancements in electronics and manufacturing methods. The purpose of this thesis is to investigate how pitching and rolling motions interact with a tandem wing. The effect of a tandem wing is mostly apparent in the hind wing, as the fore wing moves through the fluid it energizes the flow and creates a wake region. The energy put into the fluid is otherwise lost unless captured by the hind wing. The damselfly was essential inspiration in the development of this experiment, current research shows that higher levels of efficiency can be achieved by mimicking the creature’s anatomy. A pitching and plunging motion by the hindwing seeks to recreate the flapping motion used by the damselfly. Particle Image Velocimetry (PIV) was carried out on both wings to visualize the flow and develop an idea of the flow physics at work. Early results show the combined pitching and plunging motion are an effective means of vortex generation. These vortices create a pressure gradient across the hindwing, contributing to lift generation. This is particularly of interest in the take-off phase of flight. The flapping motion has the dual purpose of producing lift and thrust, this is seen as it shifts between downstroke and upstroke of the plunging cycle

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Background: Medial ulnar collateral ligament reconstruction surgery (UCLR) is a common surgical procedure performed on elite level baseball players. Physical signs and symptoms of ulnar collateral ligament (UCL) injuries requiring UCLR along with treatment have been clearly defined, however, an exact etiology of UCL injuries and methods of preventing UCLR surgery remain unclear. Objective: Systematically review and qualitatively provide an in-depth summary of recent literature about the relationships between changes in advanced pitching metrics for potential warning signs of UCL injury prior to requiring UCLR. Methods: We searched two electronic databases (PubMed, Scopus) from inception to October 2021 using a keyword search. Data extracted included author and year of publication, study design, sample size, study location, and primary outcome variables. Articles that met inclusion criteria were then evaluated using a modified Downs and Black criteria. Results: The key word search returned 51 articles of which a total of seven articles were included in the review. For the papers that met the inclusion criteria, four noted changes to velocity as potential an indicator for UCLR surgery, two identified lateralization of arm angles as an indicator of UCLR surgery, and one reported change to spin rates of specific pitches as an indicator for UCLR surgery. Conclusions: The results of this review show that changes in certain advanced pitching metrics such as spin rate, velocity, and lateralization of arm angles could be potential indicators of UCL damage. Further evaluation is needed to continue to improve our understanding of how these trends could be used as predictors of UCLR.

This thesis deals with Computational Fluid Dynamics (CFD)simulations of the flow around delta wings at high angles ofattack. These triangular wings, mainly used in militaryaircraft designs, experience the formation of two vortices ontheir lee-side at large angles of attack. The simulation ofthis vortical flow by solving the Navier-Stokes equations isthe subject of this thesis. The purpose of the work is toimprove the understanding of this flow and contribute to thedesign of such a wing by developing methods that enable moreaccurate and efficient CFD simulations. Simulations of the formation, burst and disappearance of thevortices while the angle of attack is changing are presented.The structured flow solver NSMB has been used to get thetime-dependent solutions of the flow. Both viscous and inviscidresults of a 70°-swept delta wing pitching in anoscillatory motion are reported. The creation of the dynamiclift and the hysteresis observed in the history of theaerodynamic forces are well reproduced. The second part of the thesis is focusing on automatic meshrefinement and its influence on simulations of the delta wingleading-edge vortices. All the simulations to assess the gridquality are inviscid computations performed with theunstructured flow solver EDGE. A first study reports on theeffects of refining thewake of the delta wing. A70°-swept delta wing at a Mach number of 0.2 and an angleof attack of 27° where vortex breakdown is present abovethe wing, is used as testcase. The results show a strongdependence on the refinement, particularly the vortex breakdownposition, which leads to the conclusion that the wake should berefined at least partly. Using this information, a grid for thewing in the wind tunnel is created in order to assess theinfluence of the tunnel walls. Three sensors for automatic meshrefinement of vortical flows are presented. Two are based onflow variables (production of entropy and ratio of totalpressures) while the third one requires an eigenvalue analysisof the tensor of the velocity gradients in order to capture theposition of the vortices in the flow. These three vortexsensors are successfully used for the simulation of the same70° delta wing at an angle of attack of 20°. Acomparison of the sensors reveals the more local property ofthe third one based on the eigenvalue analysis. This lattertechnique is applied to the simulation of the wake of a deltawing at an angle of attack of 20°. The simulations on ahighly refined mesh show that the vortex sheet shed from thetrailing-edge rolls up into a vortex that interacts with theleading-edge vortex. Finally the vortex-detection technique isused to refine the grid around a Saab Aerosystems UnmannedCombat Air Vehicle (UCAV) configuration and its flight dynamicscharacteristics are investigated. Key words:delta wing, high angle of attack, vortex,pitching, mesh refinement, UCAV, vortex sensor, tensor ofvelocity gradients.

Le présent travail de thèse s’inscrit dans le contexte fondamental de la propulsion marine instationnaire. Il analyse les performances propulsives des profils de différents rapports d’aspects (envergure par rapport à la corde), en oscillation harmonique de tangage. On modélise la principale partie active d’un système propulsif naturel, tel une nageoire caudale de poisson, par des profils simples, minces et rigides quasiment identiques, à l’exception du rapport d’aspect très important du premier profil (4.8), dit bidimensionnel, et très faible du second (1/6), dit tridimensionnel. Le mouvement de tangage est imposé au tiers de corde, en partant du bord d’attaque des profils immergés dans un écoulement. L’objectif étant de faire varier le nombre de Strouhal, basé sur l’amplitude d’excursion totale du bord de fuite du profil, dans une gamme relativement faible et étroite, où évoluent plusieurs espèces aquatiques. Cette gamme est donc intéressante pour l’étude des systèmes propulsifs artificiels. L’aptitude à la propulsion a été déduite en analysant la structure de l’écoulement induit dans le sillage, et en déterminant l’effort réel exercé par le profil sur l’écoulement. En raison des effets importants de la traînée induite associée aux tourbillons marginaux et de ceux de la traînée visqueuse, inversement proportionnelle au rapport d’aspect, il apparait que les performances propulsives du profil tridimensionnel sont bien moindres que celles du profil bidimensionnel. L’influence des configurations du battement sur les performances propulsives a également été étudiée. / This thesis work is part of the fundamental context of unsteady marine propulsion. The propulsive performances of different aspect ratios (span to corde) profiles, in harmonic pitching motion are analyzed. The main active part of a natural propulsion system, such as a fish caudal fin, is modelled by simple, thin and rigid profiles that are almost identical, with the exception of the very high aspect ratio of the first profile (4.8), called two-dimensional, and very low aspect ratio of the second (1/6), called three-dimensional. The pitching motion is imposed on the third corde, starting from the leading edge of the profiles immersed in a flow. The objective is to vary the Strouhal number, based on the total excursion amplitude of the trailing edge of the profile, over a relatively small and narrow range, where several aquatic species evolve. This range is therefore interesting for the study of artificial propulsion systems. The propulsion capability was inferred by analyzing the structure of the induced flow in the wake, and by determining the actual force exerted by the profile on the flow. Due to the significant effects of the induced drag associated with marginal vortices and those of the viscous drag, inversely proportional to the aspect ratio, it appears that the propulsive performance of the three-dimensional profile is much lower than that of the two-dimensional profile. The influence of flapping parameters on propulsive performance has also been studied.

Introduction: Baseball pitching is considered one of the most intense aspects within the game of baseball, as well as the most complicated dynamic throwing task in all of sports. The biomechanics of pitching have been heavily investigated in an attempt to identify optimal pitching mechanics in terms of pitching performance. Previous quantified upper body kinetics research has concluded that improved muscle strength is needed in attempting to achieve adequate upper body kinetics and efficient pitching performances. Therefore, it is the purpose of this research study to compare the lower extremity muscle and upper extremity muscle activation patterns and kinematic variables associated with the curveball pitch and the fastball pitch when pitching from the wind-up and stretch position. Methods: Twelve skilled (competed at the NCAA collegiate level) baseball pitchers volunteered to be research subjects for this study. The participants were fitted with six surface electromyography (EMG) bipolar electrodes (Delsys Inc., Boston, Massachusetts) on the stride leg biceps femoris, medial gastrocnemius, ipsilateral side (throwing arm side) lower trapezius, upper trapezius, triceps brachii and biceps brachii. Each participant underwent maximum voluntary isometric contraction (MVIC) testing and then performed a pitching analysis. All EMG variables of interest were normalized using MVIC data and then compared between pitching types and pitch delivery. Shoulder rotation, shoulder abduction, elbow flexion and extension, elbow angular velocity and pelvis rotation were determined using motion capture (Motion Analysis Corp., Santa Rosa, SA) and Visual 3D software (C-Motion Inc., Germantown, MD). Paired t-tests and factorial analyses were performed using SPSS (p ≤ 0.05). Results and Discussion: Significant differences in the peak and mean muscle activity for the fastball and curveball pitched from wind-up and stretch position were observed. Significant differences in the kinematic variables between the fastball and curveball from the wind- up and stretch were also observed. These findings suggest that upper and lower muscle activity could be associated with enhanced pitching technique and pitching performance. Pitching kinematic differences associated with the diverse pitch types as well as the multiple pitch deliveries may impact the overall “wear and tear” on a pitcher’s health and pitching arm. Conclusions: Many differences were found, between both the pitching type and the pitching delivery as well as the kinematic variables. These findings suggest that upper and lower muscle activity could be associated with enhanced pitching technique and pitching performance to keep a baseball pitcher healthy and on the pitching mound longer into the season, decreasing the rate of injury. Shoulder rotation and pelvis rotation, as well as the elbow angular velocity and elbow flexion-extension, have an impact on the pitcher’s ability to stay off the disabled list and in the game longer. Determining pitch types along with delivery types that enhance the pitcher’s ability to stay active without injury will provide a way to make the game of baseball safer for the future generation of all stars.

The ulnar collateral ligament (UCL) is the primary restraint against valgus forces at the elbow. This structure cannot support the entire load placed upon the medial elbow during overhand throwing motions such as pitching a baseball. In this study we measured the contributions that different muscle groups make to the stability of the medial elbow, under conditions intended to reproduce the loads during pitching by varying the forearm position and loading conditions. We also evaluated the strength of the elbow musculature for the possibility of a training effect in the dominant arm of 11 male high school baseball pitchers. We collected surface EMG data in the two forearm positions to determine if the different positions used in various pitches have an effect on muscular action. We also tested an isometric and dissipative loading condition to determine if the muscles activity was load reactive. The four muscle groups tested were the flexor-pronator group (FP), the extensor-supinator group (ES), the tricep brachii (TB), and the pectoralis major (PM). We found significantly (p-value=0.001) higher peak activity levels of the flexor-pronator group in the neutral forearm position (79.4% MVIC �� 27.0% MVIC full trial peak, 30.8% MVIC �� 20.8% MVIC initial l50ms peak following activation) when compared to the supinated position (55.5% MVIC �� 29.6% MVIC full trial peak, 16.9% MVIC �� 14.8% MVIC initial l50ms peak following activation), which may explain the link between breaking pitches and medial elbow injury. We found an increase (p-value=0.001) in force output of the dominant arm (49.3 N/kg �� 12.5 N/kg) over the non-dominant arm (38.1 N/kg �� 11.0 N/kg). This finding is attributed to a training effect, which assists in protecting the elbow. These findings help provide baseline muscle activity information on protection of the medial soft tissue structures of the elbow. / Graduation date: 2004

In this study we set a pitching fluid tank on a floating platform with two vertical springs on both sides to support it. By assuming that the fluid in the tank is un-compressible and in-viscous and that there are no breaking waves existing, we observe the dynamic responses of the fluid in the tank and the interactions between the tank and the floating platform under wave forces. Using numerical simulations to analyze sloshing forces of the fluid and responses of the floating platform, we compute the work of the couple system in different cases and finally get normalizing results to provide for different sizes. The main purpose of this study is to gather wave power into a composite floating platform via the vibration of the floating and the pitching motion of the tank induced by wave forces, to transform the wave power into mechanical energy, and to reduce the angle of the vibration, making the floating platform stable and improving the safety.

<p>This thesis deals with Computational Fluid Dynamics (CFD)simulations of the flow around delta wings at high angles ofattack. These triangular wings, mainly used in militaryaircraft designs, experience the formation of two vortices ontheir lee-side at large angles of attack. The simulation ofthis vortical flow by solving the Navier-Stokes equations isthe subject of this thesis. The purpose of the work is toimprove the understanding of this flow and contribute to thedesign of such a wing by developing methods that enable moreaccurate and efficient CFD simulations.</p><p>Simulations of the formation, burst and disappearance of thevortices while the angle of attack is changing are presented.The structured flow solver NSMB has been used to get thetime-dependent solutions of the flow. Both viscous and inviscidresults of a 70°-swept delta wing pitching in anoscillatory motion are reported. The creation of the dynamiclift and the hysteresis observed in the history of theaerodynamic forces are well reproduced.</p><p>The second part of the thesis is focusing on automatic meshrefinement and its influence on simulations of the delta wingleading-edge vortices. All the simulations to assess the gridquality are inviscid computations performed with theunstructured flow solver EDGE. A first study reports on theeffects of refining thewake of the delta wing. A70°-swept delta wing at a Mach number of 0.2 and an angleof attack of 27° where vortex breakdown is present abovethe wing, is used as testcase. The results show a strongdependence on the refinement, particularly the vortex breakdownposition, which leads to the conclusion that the wake should berefined at least partly. Using this information, a grid for thewing in the wind tunnel is created in order to assess theinfluence of the tunnel walls. Three sensors for automatic meshrefinement of vortical flows are presented. Two are based onflow variables (production of entropy and ratio of totalpressures) while the third one requires an eigenvalue analysisof the tensor of the velocity gradients in order to capture theposition of the vortices in the flow. These three vortexsensors are successfully used for the simulation of the same70° delta wing at an angle of attack of 20°. Acomparison of the sensors reveals the more local property ofthe third one based on the eigenvalue analysis. This lattertechnique is applied to the simulation of the wake of a deltawing at an angle of attack of 20°. The simulations on ahighly refined mesh show that the vortex sheet shed from thetrailing-edge rolls up into a vortex that interacts with theleading-edge vortex. Finally the vortex-detection technique isused to refine the grid around a Saab Aerosystems UnmannedCombat Air Vehicle (UCAV) configuration and its flight dynamicscharacteristics are investigated.</p><p><b>Key words:</b>delta wing, high angle of attack, vortex,pitching, mesh refinement, UCAV, vortex sensor, tensor ofvelocity gradients.</p>