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Stötvågsterapi och dess effekt på spasticitet hos patienter med långvarig stroke: en systematisk litteraturstudie / Extra corporeal shock wave therapy and potential effects on spasticity in patients with prolonged stroke: A systematic reviewTollstedt, Thomas, Oscar, Tschernij January 2022 (has links)
Background: Spasticity is a common symptom post-stroke which causes vast complications regarding important daily functions among patients. This manifests as a resistance in the muscle during a velocity-dependent passive motion and is commonly evaluated by using the Modified Ashworth Scale (MAS). Extra corporeal shock wave therapy (ESWT) is a relatively novel way to treat spasticity, with promising results. Purpose: The aim of the current study was to investigate the scientific evidence of ESWT as treatment regarding spasticity and function among patients with prolonged stroke. Methods: The purpose was tackled by conducting a literature review of randomized controlled trials with MAS as outcome measurement. PubMed was searched for relevant studies followed by a quality assessment through the PEDro Scale. The reliability of the evidence was assessed with the use of GRADEstud. Results: The quality of the included articles was mainly deemed as good with eight of nine articles receiving a PEDro Score of 6 or higher. This review found generally positive effects from ESWT regarding spasticity with MAS as the outcome measurement. The results regarding function were equivocal. The reliability of the results was graded as very low due to the methodological heterogeneity of the included studies. Conclusion: ESWT showed positive results regarding spasticity and function, although the reliability of the evidence was considered very low. More research is inquired to further explore the potential effects of ESWT on spasticity and function among post-stroke patients. This could potentially increase the reliability of the evidence regarding ESWT as a treatment option. / Bakgrund: Spasticitet är ett vanligt förekommande funktionsnedsättande centralt symptom bland patienter med stroke och har tendens att öka med tiden efter insjuknandet. Spasticitet manifesteras i form av ett ökat muskelmotstånd vid hastighetsberoende passivt rörelseuttag och bedöms oftast med Modified Ashworth Scale (MAS). Stötvågsterapi (ESWT) är en relativt ny behandlingsmetod och visats ha en lovande effekt mot spasticitet. Syfte: Syftet med arbetet har varit att undersöka det vetenskapliga underlaget för ESWT som behandling för spasticitet och funktion hos individer med långvarig stroke. Metod: Arbetets syfte har angripits genom en systematisk narrativ litteraturstudie. Sökning av relevanta studier gjordes i databasen PubMed och skulle uteslutande vara randomiserade kontrollerade studier med MAS som utfallsmått. Studierna utvärderades gällande risk för snedvridning genom PEDro Scale. Tillförlitligheten i evidensen av effekterna av ESWT har bedömts med GRADEstud. Resultat: Arbetets urval bedömdes ha låg risk för snedvridning då åtta av nio artiklar fick ≥ 6 poäng på PEDro Scale. ESWT sågs övergripligt ha positiva effekter på spasticitet mätt med MAS, både som isolerad och kombinerad behandling. Gällande funktion var resultaten mer tvetydiga. Dock bedömdes tillförlitligheten gällande evidensen för effekterna som mycket låg pga. genomlöpande heterogenitet bland studierna gällande design och urval. Slutsatser: Övergripligt visade ESWT-behandling ha en positiv effekt på spasticitet och funktion. Tillförlitligheten i evidensen bedömdes dock som mycket låg. Mer forskning efterfrågas i att belysa effekterna av ESWT på patienter med stroke för att uppnå högre tillförlitlighet.
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EFFECT OF ANGLE OF ATTACK ON INSTABILITY AND TRANSITION ON A FINITE-SPAN COMPRESSION RAMP IN QUIET HYPERSONIC FLOWAdelbert Ayars Francis III (16648539) 26 July 2023 (has links)
<p>This research focuses on experiments on compression-induced shock wave/boundary-layer interactions conducted in the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) at Purdue University. The BAM6QT facilitates a low-freestream-noise hypersonic test environment more similar to that experienced in flight than a conventional wind tunnel. Measurements were captured on two sliced 7° half-angle cones with finite-span compression ramps. On the first, the slice was cut parallel to the axis of the cone to build upon previous measurements in hypersonic flow. While similar geometries have been analyzed for over 30 years in experiment and computation, there are significant gaps in understanding of the underlying mechanisms leading to instability and transition on the ramp. Further, in low-noise Mach 6 flow, the boundary layer separated at the leading edge of the slice, which is unlikely to occur on a real flight vehicle. Thus, on the second model, the slice was cut at a 4° incline to the</p>
<p>cone axis to facilitate the growth of an attached laminar boundary layer on the slice. Using this configuration, the ramp-induced boundary-layer thickening initiated between the slice leading edge and the ramp leading edge, allowing the investigation of a ‘naturally’ formed separated region. </p>
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<p>Data were captured at angles of attack ranging from 0° to 6°, on compression ramp angles ranging from 10° to 20°, and for freestream Reynolds numbers of 2.5×10^6/m to 12×10^6/m. To analyze the mean-flow behavior of the separation bubble as it changes with the above parametrics, time-averaged schlieren visualization was used to provide off-surface visualization of the flowfield, allowing estimates of reattachment position and separation bubble size. In all cases, reattachment position was shown to move upstream with an increase in angle of attack, an increase in ramp angle, and an increase in Reynolds number. However, on the model with the inclined slice, the Reynolds number impacted reattachment location to a much lesser extent. </p>
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<p>Heat transfer measurements on the ramp revealed regions with the most significant aerothermal loading. Streamwise streaks of high heating originating at the ramp edges and centerline were observed to increase in magnitude with an increase in Reynolds number, angle of attack, and ramp angle. On the model with the inclined slice, many streaks of high heating were observed that increased in quantity and magnitude with angle of attack and ramp angle. Root mean squared pressure fluctuations computed from surface pressure measurements were shown to follow similar trends to centerline heat transfer results for both models. Angle of attack, ramp angle, and slice angle are shown to play a dominant role in transition. Finally, the importance of quiet tunnels is made remarkably clear, as the BAM6QT operating in its conventional-noise configuration resulted in drastically different results.</p>
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<p>For measurement of shock wave/boundary-layer instabilities, schlieren frames were captured at 100,000 fps to allow measurement of low-to-mid-frequency fluctuations of the recirculation zone edge. Shear layer flapping frequencies were found to occur at around 1100–1200 Hz, which increased with angle of attack to up to 1600 Hz. It is likely that this is an inherent instability in the separation bubble itself, rather than a function of freestream disturbances, and may be indicative of an ‘expansion and relaxation’ effect known as bubble breathing. Additional measurements using low-frequency-capable pressure sensors must be captured to determine whether this breathing effect manifests on the model slice or ramp. </p>
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Účinky rázové vlny v léčbě tendinopatie Achillovy šlachy / The Effects of Extracorporeal Shock Wave Therapy in Treatment of Achilles TendinopathyKatolický, Jakub January 2021 (has links)
Diplomová práce Účinky rázové vlny v léčbě tendinopatie Achillovy šlachy 1 Abstract This thesis focuses on the observation of the effects of low-energetic focused extracorporeal shock wave therapy (ESWT) in the treatment of Achilles tendinopathy. The theoretical part summarizes the current knowledge of anatomical, histological, kinesiological and biomechanical aspects of Achilles tendon (AT), as well as pathological processes, which can be described as Achilles tendinopathy, their differential diagnosis and treatment options. Last but not least, we present up-to-date information on the physical principles and biological effects of ESWT, not only in the treatment of AT diseases. The main goal of our research was to determine the effectiveness of low-energetic focused ESWT in the treatment of Achilles tendinopathy in comparison to the placebo group. The subject of observation was not only changes in clinical manifestations, but also possible changes in the morphology of AT using ultrasonography (USG). Methods: A total of 20 patients with symptomatic Achilles tendinopathy was included in the study, while only 18 of them completed the entire program, and therefore only the results of these patients were evaluated. They were randomly divided into two groups in 1:1 ratio. Group A was treated by ESWT with...
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Characteristics of Hypersonic Wing-Elevon-Cove FlowsRobert A Alviani (14373414) 12 January 2023 (has links)
<p>This dissertation covers a computational investigation into hypersonic flight vehicle geometric imperfections, with a focus on wing-elevon-cove configurations. The primary region of focus for the overall research was the cove region at the juncture of the main wing element and the elevon. This region is associated with the shock-wave/boundary-layer interaction produced by the control surface deflection. There also exists a centrifugal instability at the cove, due to streamline curvature, which is associated with the production of Görtler vortices. The content includes three projects revolving around hypersonic wing-elevon-cove flows. These flows were computed with improved delayed detached-eddy simulation.</p>
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<p>The first project was a computational investigation simulating the NASA experimental study done by W.D. Deveikis and W. Bartlett in 1978. This experiment consisted of hypersonic high Reynolds number wind tunnel tests for a shuttle-type reentry vehicle. The computational aerothermodynamic surface loadings for this project were compared to the experimental published data. Grounded with the agreement with mean surface data, this project expanded on the topics explored in the experimental study to include topics such as flow visualization and statistical analysis. The second and third project are extensions of this work and were done in collaboration with Purdue University and the University of Tennessee Space Institute (UTSI). A swept wing-elevon-cove model was designed by Carson Lay, of Purdue University, and is currently being employed in ongoing experiments in the Purdue Boeing/AFOSR Mach 6 Quiet Tunnel (BAM6QT) and at the Tennessee Aerothermodynamics Laboratory (TALon). A computational investigation on hypersonic high Reynolds number wing-elevon-cove flows was conducted with this model, where both corresponding experimental facility conditions were employed. At this time, the experimental data are limited; however, future experimental and computational collaboration is expected.</p>
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<p>The motivation behind this research was to expand the knowledge on hypersonic wing-elevon-cove flows, gap heating, and the low-frequency unsteadiness in shock-wave/boundary-layer interactions. Therefore, the intended goal of this work was to provide an accurate characterization of the three hypersonic wing-elevon-cove flows. This was accomplished by using computational data to produce flowfield visualizations, analyze aerothermodynamic loadings, and conduct statistical flow analyses. The results on the three hypersonic wing-elevon-cove computations are presented, analyzed, and discussed throughout this dissertation.</p>
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Computations of shock-wave/boundary layer interactions over fins in turbulent flowRaghav Chari (13171305) 09 September 2022 (has links)
<p>High speed flows in engineering applications are often characterized by shock-wave/boundary layer interactions (SWBLI) and three-dimensional flows. This thesis aims to study commonly employed turbulence models in the context of configurations featuring SWBLI and 3D flows. Computational Fluid Dynamics (CFD) simulations of flow over a 20 degree isentropic compression curved fin were performed, and the results were compared with published experimental data. Two variations of the Spalart-Allmaras (SA) turbulence model, and two variations of the Menter Shear Stress Transport (SST) turbulence model were tested, and their ability to predict mean flow data was compared. All four models predict the correct flow structure, but the SA models display higher error in predicting Pitot pressure in the curved fin 3D boundary layer. CFD simulations of flow over a sharp fin were performed using the same four turbulence models, and mean flow data were compared to published experimental and computational data. Simulated flow profiles showed good accuracy in the regions away from the shock structure, but did not accurately predict flow in the supersonic regions in the vicinity of the shock wave. Time-accurate IDDES simulations of both configurations were performed, and neither configuration showed any deviation from the steady state solution.</p>
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Mechanics of Phase Transformation in NiTi Shape Memory Alloys at The Atomistic ScaleYazdandoost, Fatemeh 14 February 2019 (has links)
During the past decade, Shape Memory Alloys (SMAs), particularly Nickel-Titanium (NiTi) alloys, have received increasing attention mainly because of their promising role to be integrated into multifunctional systems for actuation, morphing, and sensory capabilities in a broad variety of applications including biomedical, aerospace and seismological engineering. The unique performance of all the novel devices developed by SMAs relies on either the shape memory effect or pseudoelasticity, the two distinctive properties of SMAs. Both these unique properties are based on the inherent capability of SMAs to have two stable lattice structures at different stress or temperature conditions, and the ability of changing their crystallographic structure by a displacive phase transformation between a high-symmetry austenite phase and a low-symmetry martensite phase, in response to either mechanical or thermal loading. These properties make them a superior candidate for using as damping materials under high-strain-rate loading conditions in different engineering fields. SMA materials used in the most applications are polycrystalline in nature. In polycrystalline SMAs at the bulk-level, in addition to the phase transformation at the lattice-level, the thermomechanical response is also highly sensitive to the microstructural properties. In this work, the microstructure, as well as defects, such as dislocations and the stacking faults, are studied in the NiTi crystalline structure. In addition, the performance of NiTi under shock wave loading and vibrations, and their energy dissipation capabilities are examined using computational modeling, globally and locally. The effect of graphitic and metal structures, as reinforcements, on the performance of NiTi matrix composites under static and shock stress wave loading conditions is also investigated at the atomistic scale. / PHD / During the past decade, Shape Memory Alloys (SMAs), particularly Nickel-Titanium (NiTi) alloys, have received increasing attention mainly because of their promising role to be integrated into multifunctional systems for actuation, morphing, and sensory capabilities in a broad variety of applications including biomedical, aerospace and seismological engineering. The unique performance of all the novel devices developed by SMAs relies on their ability of changing their crystallographic structure by a displacive phase transformation between a high-symmetry austenite phase and a low-symmetry martensite phase, in response to either mechanical or thermal loading. These properties make them a superior candidate for using as damping materials in different engineering fields. In this work, the microstructure, as well as defects are studied in the NiTi crystalline structure. In addition, the performance of NiTi under shock wave loading and vibrations, and their energy dissipation capabilities are examined using computational modeling, globally and locally. The effect of graphitic and metal structures, as reinforcements, on the performance of NiTi matrix composites under static and shock stress wave loading conditions is also investigated at the atomistic scale.
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From Transformation to Therapeutics : Diverse Biological Applications of Shock WavesGanadhas, Divya Prakash January 2014 (has links) (PDF)
Chapter–I Introduction
Shock waves appear in nature whenever the different elements in a fluid approach one another with a velocity larger than the local speed of sound. Shock waves are essentially non-linear waves that propagate at supersonic speeds. Such disturbances occur in steady transonic or supersonic flows, during explosions, earthquakes, tsunamis, lightening strokes and contact surfaces in laboratory devices. Any sudden release of energy (within few μs) will invariably result in the formation of shock wave since it is one of the efficient mechanisms of energy dissipation observed in nature. The dissipation of mechanical, nuclear, chemical, and electrical energy in a limited space will result in the formation of a shock wave. However, it is possible to generate micro-shock waves in laboratory using different methods including controlled explosions. One of the unique features of shock wave propagation in any medium (solid, liquid or gases) is their ability to instantaneously enhance pressure and temperature of the medium. Shock waves have been successfully used for disintegrating kidney stones, non-invasive angiogenic therapy and osteoporosis treatment. In this study, we have generated a novel method to produce micro-shock waves using micro-explosions. Different biological applications were developed by further exploring the physical properties of shock waves.
Chapter – II Bacterial transformation using micro-shock waves
In bacteria, uptake of DNA occurs naturally by transformation, transduction and conjugation. The most widely used methods for artificial bacterial transformation are procedures based on CaCl2 treatment and electroporation. In this chapter, controlled micro-shock waves were harnessed to develop a unique bacterial transformation method. The conditions have been optimized for the maximum transformation efficiency in E. coli. The highest transformation efficiency achieved (1 × 10-5 transformants per cell) was at least 10 times greater than the previously reported ultrasound mediated transformation (1 × 10-6 transformants per cell). This method has also been successfully employed for the efficient and reproducible transformation of Pseudomonas aeruginosa and Salmonella Typhimurium. This novel method of transformation has been shown to be as efficient as electroporation with the added advantage of better recovery of cells, economical (40 times cheaper than commercial electroporator) and growth-phase independent transformation.
Chapter – III Needle-less vaccine delivery using micro-shock waves
Utilizing the instantaneous mechanical impulse generated behind the micro-shock wave during controlled explosion, a novel non-intrusive needleless vaccine delivery system has been developed. It is well established, that antigens in the epidermis are efficiently presented by resident Langerhans cells, eliciting the requisite immune response, making them a good target for vaccine delivery. Unfortunately, needle free devices for epidermal delivery have inherent problems from the perspective of patient safety and comfort. The penetration depth of less than 100 µm in the skin can elicit higher immune response without any pain. Here the efficient utilization of the device for micro-shock wave mediated vaccination was demonstrated. Salmonella enterica serovar Typhimurium vaccine strain pmrG-HM-D (DV-STM-07) was delivered using our device in the murine salmonellosis model and the effectiveness of the delivery system for vaccination was compared with other routes of vaccination. The device mediated vaccination elicits better protection as well as IgG response even in lower vaccine dose (ten-fold lesser), compare to other routes of vaccination.
Chapter – IV In vitro and in vivo biofilm disruption using shock waves
Many of the bacteria secrete highly hydrated framework of extracellular polymer matrix on encountering suitable substrates and get embedded within the matrix to form biofilm. Bacterial colonization in biofilm form is observed in most of the medical devices as well as during infections. Since these bacteria are protected by the polymeric matrix, antibiotic concentration of more than 1000 times of the MIC is required to treat these infections. Active research is being undertaken to develop antibacterial coated medical implants to prevent the formation of biofilm. Here, a novel strategy to treat biofilm colonization in medical devices and infectious conditions by employing shock waves was developed. Micro-shock waves assisted disintegration of Salmonella, Pseudomonas and Staphylococcus biofilm in urinary catheters was demonstrated. The biofilm treated with micro-shock waves became susceptible to antibiotics, whereas the untreated was resistant. Apart from medical devices, the study was extended to Pseudomonas lung infection model in mice. Mice exposed to shock waves responded well to ciprofloxacin while ciprofloxacin alone could not rescue the mice from infection. All the mice survived when antibiotic treatment was provided along with shock wave exposure. These results clearly demonstrate that shock waves can be used along with antibiotic treatment to tackle chronic conditions resulting from biofilm formation in medical devices as well as biological infections.
Chapter – V Shock wave responsive drug delivery system for therapeutic application
Different systems have been used for more efficient drug delivery as well as targeted delivery. Responsive drug delivery systems have also been developed where different stimuli (pH, temperature, ultrasound etc.) are used to trigger the drug release. In this study, a novel drug delivery system which responds to shock waves was developed. Spermidine and dextran sulfate was used to develop the microcapsules using layer by layer method. Ciprofloxacin was loaded in the capsules and we have used shock waves to release the drug. Only 10% of the drug was released in 24 h at pH 7.4, whereas 20% of the drug was released immediately after the particles were exposed to shock waves. Almost 90% of the drug release was observed when the particles were exposed to shock waves 5 times. Since shock waves can be used to induce angiogenesis and wound healing, Staphylococcus aureus skin infection model was used to show the effectiveness of the delivery system. The results show that shock wave can be used to trigger the drug release and can be used to treat the wound effectively.
A brief summary of the studies that does not directly deal with the biological applications of shock waves are included in the Appendix. Different drug delivery systems were developed to check their effect in Salmonella infection as well as cancer. It was shown for the first time that silver nanoparticles interact with serum proteins and hence the antimicrobial properties are affected. In a nutshell, the potential of shock waves was harnessed to develop novel experimental tools/technologies that transcend the traditional boundaries of basic science and engineering.
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Retrográdní studie efektu terapie rázovou vlnou u funkčních poruch muskuloskeletálního systému / Retrograde study of the effect of the shock ware therapy for the functional disorders of the musculosceletal systemHoráková, Kateřina January 2013 (has links)
This thesis assesses the effectiveness of shock wave therapy for dysfunctional disorders of the musculoskeletal system. While we are well aware of the physical principles and history of shock wave generators, opinion differs on the treatment effectiveness mechanisms. The theoretical part of this work explains the effects of shock waves on various types of tissue, the differentiation of the cells, and the analgetic effect of therapy. It summarizes the indications, side effects and contraindications of shock wave therapy. The research part of this thesis deals with the effectiveness of shock wave therapy at the Department of Rehabilitation and Sports Medicine at the Motol University Hospital, which specialises in various musculoskeletal disorders. This thesis evaluates the correlation between the effectiveness of shock wave therapy and length of time the patient has experienced difficulties before undergoing treatment. This thesis also reviews whether the number of treatment applications has the capability to influence the outcome of therapy. The study is controlled by a control group of 22 patients. The total effectiveness of shock wave therapy is p = 1,12*10-10 . The shock wave therapy effectiveness of patients with heel spur is p = 0,00176. The shock wave therapy effectiveness of patients with...
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Etude expérimentale de l'atténuation d'une onde de choc par un nuage de gouttes et validation numériqueChauvin, Alice 07 December 2012 (has links)
L'interaction entre une onde de choc plane et un nuage de gouttes d'eau homogène, monodisperse est étudiée dans un tube à choc. Les influences de la fraction volumique d'eau, αd(1 %, 0.3 % et 0.1%), rapport du volume d'eau sur le volume du nuage, de la hauteur du nuage Hd (70 cm, 40 cm et 15 cm), du diamètre des gouttes φd (250 µm et 500 µm ) et du nombre de Mach M (1.3 et 1.5) sont étudiées pour des fractions volumiques inférieures au pour cent. Lors de cette interaction, la pression en paroi du tube à choc est mesurée et la visualisation du nuage est obtenue par une méthode ombroscopique directe. Une évolution temporelle caractéristique de la pression induite par la propagation d'une onde de choc dans un tel milieu, est mise en évidence. Cette allure, diffère significativement de celle obtenue avec un nuage constitué de particules solides: la fragmentation des gouttes en est responsable. Une zone où la pression diminue directement après le pic de pression est alors observée aux stations de mesure localisées dans le nuage. L'atténuation de la surpression est mise en évidence: elle peut atteindre 80% du pic de pression mesuré sans nuage. Dans la partie numérique de ce travail, deux modèles de fragmentation sont implémentés, comparés et validés dans un code de calcul monodimensionel, instationnaire, Eulérien appliqué aux écoulements dilués (αd<1 %). On montre que la formulation du taux de production des gouttes selon le taux d'accroissement soit de leur nombre, soit de leur diamètre doit être utilisée respectivement soit avec, soit sans la prise en compte l'étape de déformation de la fragmentation. / The interaction between a planar shock wave and an both homogeneous and monodispersed droplet water cloud is studied in a shock tube. The effects of the water volume fraction αd (1% %, 0.3 % et 0.1%), ratio between the volume of water and the volume of the cloud, the height of the two-phase medium Hd (70 cm, 40 cm et 15 cm), the droplets diameters φd (250 µm et 500 µm ) and the Mach number M (1.3 et 1.5) are studied for a volume fraction smaller than one per cent. During this interaction, the pressure is measured and the visualization of the cloud is obtained by direct shadowgraphy. A characteristic temporal evolution of the pressure induced by the propagation of the shock wave in such a mixture is highlighted. This behavior differs significatively from the one obtained with a solid particles cloud : the droplet atomization is responsible of this change. A zone where the pressure decreases directly after the pressure peak is observed at different stations located into the water cloud. The mitiagtion of the overpressure is shown: it can reach 80%of the pressure peak measured without cloud. In the numerical part, two fragmentation models are added, compared and validated in a comptutational, one dimensional, instationnary, Eulerien code in the case of dilute flows (αd<1 %). We show that the formulation of the production rate of droplets defined by the number of droplets growth, or the diameter droplet growth, must be used, respectively, with and without taking into account the deformation stage of the droplet breakup. Thus, the numerical results are in good agrement with those obtained experimentally.
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Modélisation des écoulements transsoniques décollés pour l'étude des interactions fluide-structure / Modelling of transonic separated flows for fluid-structure interaction studiesRendu, Quentin 12 December 2016 (has links)
Les écoulements transsoniques rencontrés dans le cadre de la propulsion aéronautique et spatiale sont associés à l'apparition d'ondes de choc. En impactant la couche limite se développant sur une paroi, un gradient de pression adverse est généré qui conduit à l'épaississement ou au décollement de la couche limite. Lors de la vibration de la structure, l'onde de choc oscille et interagit avec la couche limite, générant une fluctuation de la pression statique à la paroi. Il s'ensuit alors un échange d'énergie entre le fluide et la structure qui peut être stabilisant ou au contraire conduire à une instabilité aéroélastique (flottement). La modélisation de la réponse instationnaire de l'interaction onde de choc / couche limite pour l'étude des interactions fluide-structure est l'objet de ce travail de recherche. Il s'appuie sur la résolution des équations de Navier-Stokes moyennées (RANS) et la modélisation de la turbulence. Les méthodes et modèles utilisés ont été validés à partir de résultats expérimentaux issus d'une tuyère transsonique dédiée à l'étude des interactions fluide-structure. Ces travaux sont ensuite appliqués à l'amélioration de la prédiction du flottement en turbomachine. Une méthode linéarisée en temps permettant la résolution des équations RANS dans le domaine fréquentiel est utilisée. Nous confirmons l'importance de la dérivation du modèle de turbulence lors de la prédiction d'une interaction forte entre une onde de choc et une couche limite décollée. Une méthode de régularisation est présentée puis appliquée aux opérateurs non dérivables du modèle de turbulence k-! de Wilcox (2006). La prédiction de la réponse instationnaire de l'interaction onde de choc / couche limite dans une tuyère est évaluée à partir de simulations bidimensionnelles et présente un bon accord avec les données expérimentales. En évaluant l'influence de la fréquence réduite, une instabilité aéroélastique de type flottement transsonique est identifiée. Un dispositif de contrôle, reposant sur la génération d'ondes de pression rétrogrades à l'aval de la tuyère, est proposé puis validé numériquement. Enfin, une méthodologie est proposée pour comprendre les mécanismes aérodynamiques conduisant au flottement. Pour cela, il a été réalisé un dessin provisoire d'une soufflante transsonique à fort taux de dilution. Cette soufflante, l'ECL5, est destinée à l'étude expérimentale des instabilités aérodynamiques et aéroélastiques. La méthodologie proposée repose sur la simulation 2D d'une coupe de tête et met à profit la linéarisation pour analyser la contribution de sources locales en fonction de la fréquence réduite, du diamètre nodal et de la déformée modale / Transonic flows, which are common in aeronautical and spatial propulsion systems, produce shock-waves over solid boundaries. When a shock-wave impacts the boundary layer, an adverse pressure gradient is generated and a thickening or even a separation of the boundary layer is induced. If the solid boundary vibrates, the shock-wave oscillates, interacts with the boundary layer and produce a fluctuation of the static pressure at the wall. This induces an exchange of energy between the fluid and the structure which can be stabilising or lead to an aeroelastic instability (flutter).The main objective of this PhD thesis is the modelling of the unsteady behaviour the simulation of the shock-wave/boundary layer interaction for fluid-structure interaction studies. To this end, simulations have been carried out to solve Reynolds-Averaged Navier-Stokes equations using two equations turbulence model. The method is validated thanks to experimental data obtained on a transonic nozzle dedicated to aeroelastic studies. This method is then use to increase the predictability of flutter events in turbomachinery.A time linearised frequency-domain method is applied to RANS equations. It is shown that the unsteady behaviour of the turbulent boundary-layer contributes to the fluctuating static pressure when the shock-wave boundary layer interaction is strong. Hence, the frozen turbulence assumption is not valid and the turbulence model must be derivated. Thus, the regularisation of the non derivable operators is proposed and applied on k-? Wilcox (2006) turbulence model.The unsteady behaviour of the shock-wave/boundary-layer interaction in a transonic nozzle is evaluated thanks to 2D numerical simulations and shows good agreement with experimental data. When varying the reduced frequency an aeroelastic instability is found, known as transonic flutter. An active control device generating backward travelling pressure waves is then designed and numerically validated.Finally, a methodology is proposed to understand the aerodynamic onsets of transonic flutter. To this end, a preliminary design of a high bypass ratio transonic fan has been carried out. This fan, named ECL5, is dedicated to experimental aerodynamic and aeroelastic studies. The methodology relies on 2D simulations of a tip blade passage and uses linearisation to analyse the contribution of local sources as a function of reduced frequency, nodal diameter and mode shape
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