Diese Arbeit beschäftigt sich mit zwei verschiedenen Modellsystemen, die Aufschluss über die Mechanik und die Dynamik von zellulären Systemen geben sollen. Zum Einsatz kommt zum einen der Modellorganismus Dictyostelium discoideum, dessen kollektives Migrationsverhalten analysiert wird und zum anderen wird die Mechanik von aktingefüllten Riesenvesikeln als artifizielles Modellsystem etabliert.

This work deals with spatially-evolving supersonic turbulent boundary layers over adiabatic and cold walls at M∞ = 2 and up to Re0 ≈ 2600 using 3 different SGS models. The numerical methodology is based on high-order split-centered scheme to discretize the convective fluxes of the Navier-Stokes equations . For the adiabatic case, it is demonstrated that all SGS models require a comparable minimum grid-refinement in order to capture accurately the near-wall-turbulence. Overall, the models exhibit correct behavior when predictiong the dynamic properties, but show different performances for the temperature distribution in the near-wall region. For the isothermal case, it is found that the compressibility effects are not enhanced due to the wall cooling. As expected, the total temperature fluctuations are not negligible in the near-wall region. The study shows that the anti-correlation linking both velocity and temperature fields, derived from the Morkovin's hypothesis, is not satisfied.

Des solutions d'isolat de protéine de lactosérum (WPI) et d'isolat de protéine de soja (SPI) ont été chauffées à différentes concentrations en protéines conduisant à la formation d'agrégats fractals polydisperses de taille moyenne variable. Lastructure des solutions a été analysée par diffusion de la lumière en fonction de la concentration en protéine. La compressibilité osmotique et la longueur de corrélation dynamique diminuent quand la concentration augmente deviennent indépendantes de la taille initiale des agrégats pour les suspensions denses. Pour une taille d'agrégat donnée, la viscosité augmente initialement exponentiellement avec la concentration croissante puis diverge. Plus lesagrégats sont grands, plus l’augmentation de la viscosité apparaît à des concentrations faibles. La dépendance avec la concentration de la viscosité des solutions d'agrégats fractals est beaucoup plus forte que celle de microgels. Le comportement de mélanges de différents types d’agrégats (fractals/fractals ; fractals/microgels et WPI/SPI) a étéétudié principalement par rhéologie.Le recouvrement de fluorescence après photoblanchiment (FRAP) a été utilisé pour étudier la diffusion de chaînes de dextran marquées par des fluorophores dans des solutions d’agrégats et des gels de WPI. Une diffusion brownienne estobservée dans des suspensions d’agrégats et des gels faibles formés juste au-delà de Cg avec un coefficient de diffusion (D) qui diminue avec l'augmentation de la concentration mais, avec une dépendance plus faible que celle de la viscosité (). A des concentrations plus élevées, des gels densément réticulés sont formés, ce qui induit une forte diminution de la mobilité des chaînes de dextran. Pour ces systèmes, la recouvrance de la fluorescence est logarithmique avec le temps,suggérant une distribution exponentielle des coefficients de diffusion. La diffusion des chaînes de dextran a également été étudiée en fonction de la concentration en protéines pour les suspensions de trois types d'agrégats de WPI (petits et grands fractals et microgels). / Polydisperse fractal aggregates of varying average sizes were formed when solutions of whey protein isolate and soy protein isolate were heated at different protein concentrations and at neutral pH. The structure of these fractals aggregates solutions was analyzed by light scattering as a function of protein concentration. In dense suspension, the osmotic compressibility and the correlation length decreases with increasing concentration and become independent of the initial aggregate size. In this concentration regime, the aggregates are strongly interpenetrated and can be visualized as a set of "blobs". For a fixed aggregate size, the viscosity initially increases exponentially with increasing concentration and then diverges at the gel point. Larger fractal aggregates show a more important increase of the viscosity with increasing concentration than smaller aggregates, because they are less dense. The increase of the viscosity was much stronger for large fractal aggregates than for homogeneous microgels (microgels were formed by heating the WPI solution in present of CaCl2) of the same size.Dynamic light scattering, rheology and FRAP measurements were performed to investigate mixtures of different type of aggregates of WPI (fractals/fractals, fractals/microgels) and fractals of mixtures of WPI and SPI. Flow measurements were used to characterise the rheological properties of the aggregate suspension whereas Fluorescence recovery after Photobleaching (FRAP) was used to determine the self diffusion of fluorophore-labelled dextrans chains in mixtures over a wide range of concentrations. The results were compared to the concentration dependence of zero shear viscosity, gel stiffness, osmotic compressibility and correlation length. Brownian diffusion of the dextran chains was observed in aggregate suspensions and weak gels formed just above the gel point with a diffusion coefficient that decreased with increasing concentration, but the dependence was weaker than that of the viscosity. At higher concentrations, densely crosslinked gels were formed, which induced a sharp decrease in the mobility of the dextran chains. For these systems, the recovery of fluorescence was logarithmic over time, suggesting an exponential distribution of diffusion coefficients.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Susceptibility to soil degradation is a function of disturbance intensity and structure resistance, which is usually described by mesoscale properties. However, soil mechanical strength in the microscale (micromechanical) evaluated by rheology is not well known. The objective was to evaluate the micromechanical resistance of soils of Rio Grande do Sul through amplitude sweep tests under oscillatory shear, to know the variables that influence this resistance and to evaluate its relationship with physical and mechanical properties in mesoscale. Surface and subsurface horizons of eight soils, Oxisol (4), Ultisol (2), Alfisol (1) and Vertisol (1), were characterized for particle size, mineralogy, chemical, physical and mechanical in micro and mesoscale. The micromechanical resistance of soils was evaluated by rheological curves and parameters, and the influence of water content on rheological parameters was evaluated by regression analysis. The influence of soil composition on rheological parameters and the relationship between rheological parameters and physical and mechanical properties were evaluated by correlation analysis and principal component analysis. There was great variation between soils and horizons according its constitution of particle size, mineralogy and chemistry, where sand, clay, total carbon and presence of 2:1 clay minerals were the most influential factors on rheological behavior of the soils. Soil matric potential also had a strong influence on micromechanics resistance of soils. There were correlations of rheological parameters with physical properties (bulk density and soil porosity), but few correlations with mesomechanical properties (uniaxial compressibility and direct shear). The higher silt and clay content increased the microstructural resistance of the soil, where higher sand content decreased this resistance. The predominance of smectite in clay fraction increased the microstructural elasticity; the increased of kaolinite decreased the elasticity and the increased of iron oxides raised the microstructural stiffness (shear stress) of the soils. Increased water pressure increased micromechanical resistance of most soils due to meniscus force, occurring reduction in micromechanics stiffness at 10 kPa pressure due to presence of pseudosand associated with low bulk density. The increase of carbon content increased soil elasticity, but decreased soil rigidity; and cations content correlated only indirectly with rheological parameters. The larger correlation between rheological parameters and physical properties is probably due to aggregation factors being the same in both scales, such as particle size, mineralogy and their interactions. On the other hand, the low relation of soil mechanical resistance in micro and mesoscale seem influenced by different factors related to soil composition and structure. / A suscetibilidade do solo à degradação é função da intensidade da perturbação e da resistência da estrutura, a qual é normalmente descrita por propriedades em mesoescala. Entretanto, a resistência mecânica do solo em microescala (micromecânica) avaliada por meio da reologia é pouco conhecida. O objetivo foi avaliar a resistência micromecânica de solos do Rio Grande do Sul com o uso de testes de varredura de amplitude por cisalhamento oscilatório, conhecer as variáveis que influenciam essa resistência e avaliar sua relação com propriedades físicas e mecânicas em mesoescala. Os horizontes superficial e subsuperficial de oito solos das ordens Latossolo (4), Argissolo (2), Planossolo (1) e Vertissolo (1) foram caracterizados quanto à granulometria, mineralogia, propriedades químicas, físicas e mecânicas em micro e mesoescala. A resistência micromecânica dos solos foi avaliada por curvas e parâmetros reológicos e a influência do conteúdo de água sobre parâmetros reológicos foi avaliada por análise de regressão. A influência da composição do solo nos parâmetros reológicos e a relação entre parâmetros reológicos e propriedades físicas e mesomecânicas foram avaliadas por análise de correlação e análise de componentes principais. Houve grande variação entre os solos e horizontes quanto à sua constituição granulométrica, mineralógica e química, sendo areia, argila, carbono e presença de argilominerais 2:1 os fatores que mais influenciaram o comportamento reológico dos solos. A tensão de água também teve forte influência na resistência micromecânica dos solos. Foram verificadas correlações de parâmetros reológicos com propriedades físicas (densidade e porosidade do solo), mas poucas correlações com propriedades mesomecânicas (compressibilidade uniaxial e cisalhamento direto). O aumento dos teores de silte e argila aumentou a resistência micromecânica do solo, enquanto maiores teores de areia diminuíram essa resistência. O predomínio de esmectita na fração argila aumentou a elasticidade microestrutural; a caulinita diminuiu a elasticidade; e o aumento de óxidos de ferro aumentou a rigidez (tensão de cisalhamento) microestrutural dos solos. O aumento da drenagem aumentou a resistência micromecânica da maioria dos solos devido ao aumento das forças de meniscos, ocorrendo redução da rigidez micromecânica na tensão de água de 10 kPa em horizontes com presença de pseudoareia associada com baixa densidade do solo. O incremento dos teores de carbono aumentou a elasticidade do solo, mas diminuiu sua rigidez; e os teores de cátions correlacionaram-se indiretamente com parâmetros reológicos. A maior relação entre parâmetros reológicos e propriedades físicas decorre, provavelmente, dos fatores de agregação serem os mesmos em ambas as escalas, como a granulometria, a mineralogia e suas interações. Por outro lado, a relação da resistência mecânica do solo em micro e mesoescala foi pequena, pois parecem influenciadas por diferentes fatores relacionados à composição e estrutura do solo.

Cette étude porte sur la mise en forme des matériaux composites renforcés par des fibres ou des mèches de fibres courtes tels que les SMC ou les BMC. Un travail expérimental a dans un premier temps été réalisé à l’échelle macroscopique. Ce travail a permis de mettre au point un rhéomètre de compression lubrifiée ainsi que des méthodes d’essais et de dépouillement. Ceci permet de mieux caractériser la rhéologie des compounds SMC et BMC en traitant les problématiques de leur compressibilité et des frottements éventuels entre les parois du rhéomètre et la matière déformée. Un travail numérique a ensuite permis de simuler la mise en forme d’un BMC après l’identification des paramètres d’un modèle rhéologique simple à partir des données expérimentales obtenues sur le rhéomètre. Enfin, un travail expérimental à l’échelle microscopique a permis d’une part de caractériser finement les microstuctures de SMC modèles à partir de microtomographies à rayons X, et d’autre part de caractériser et de modéliser par le biais d’essais d’extraction de fibres les interactions entre les mèches formant le renfort fibreux de ces matériaux. / This study focuses on the processing of composite materials reinforced with short fibres or fibres bundles such as SMC or BMC. Firstly, an experimental work was carried-out at the macroscopic scale. This work led to the development of a lubricated compression rheometer and associated analysis methods to better characterize the rheology of SMC and BMC compounds, by accounting for the compressibility of compounds and the possible friction between the rheometer wall and the flowing composite. Numerical simulation was then achieved in order to simulate the forming of a BMC. For that purpose, the constitutive parameters of a simple tensorial rheological model were determined from experimental data obtained with the rheometer. Finally, an experimental work at the microscopic level allowed (i) the microstuctures of SMC models from X-ray microtomography micrographs and (ii) fibre pull-out experiment to be characterized, and the interaction mechanisms between the fiber bundles forming the fiber reinforcement of these materials to be modelled.

This thesis is concerned with the study of parallel mixing of two dissimilar gases under compressible conditions in the confined environment. A number of numerical studies are reported in the literature for the compressible mixing of two streams of gases where (1) both the streams are of similar gases at the same temperatures, (2) both the streams are at different temperatures with similar gases, and (3) dissimilar gases are with nearly equal temperatures. The combination of dissimilar gases at large temperature difference, mixing under compressible conditions, as in the case of scramjet propulsion, has not been adequately addressed numerically. Also many of the earlier studies have used two dimensional numerical simulation and showed good match with the experimental results on mixing layers that are inherently three dimensional in nature. In the present study, both two-dimensional (2-d) and three dimensional (3-d) studies are reported and in particular the effect of side wall on the three dimensionality of the flow field is analyzed, and the reasons of the good match of two dimensional simulations with experimental results have been discussed. Both two dimensional and three dimensional model free simulations have been conducted for a flow configuration on which experimental results are available. In this flow configuration, the mixing duct has a rectangular cross section with height to width ratio of 0.5. In the upper part of the duct hydrogen gas at a temperature of 103 K is injected through a single manifold of two Ludweig tubes and in the lower part of the duct nitrogen gas at a temperature of 2436 K is supplied through an expansion tube, both the gases are at Mach numbers of 3.1 and 4.0 respectively. Measurements in the experiment are limited to wall pressures and heat flux. The choice of this experimental condition gives an opportunity to study the effect of large temperature difference on the mixing of two dissimilar gases with large molecular weights under compressible conditions. Both two dimensional and three dimensional model free simulations are carried out using higher order numerical scheme (4th order spatial and 2nd order temporal) to understand the structure and evolution of supersonic confined mixing layer of similar and dissimilar gases. Two dimensional simulations are carried out by both SPARK (finite difference method) and OpenFOAM (finite volume method based open source software that was specially picked out and put together), while 3D model free simulations are carried out by OpenFOAM. A fine grid structure with higher grid resolution near the walls and shear layer is chosen. The effect of forcing of fluctuations on the inlet velocity shows no appreciable change in the fully developed turbulent region of the flow. The flow variables are averaged after the attainment of statistical steady state established through monitoring the concentration of inert species introduced in the initial guess. The effect of side wall on the flow structure on the mixing layer is studied by comparing the simulation results with and without side wall. Two dimensional simulations show a good match for the growth rate of shear layer and experimental wall pressures. Three dimensional simulations without side wall shows 14% higher growth rate of shear layer than that of two dimensional simulations. The wall pressures predicted by these three dimensional simulations are also lower than that predicted using two dimensional simulations (6%) and experimental (9%) results in the downstream direction of the mixing duct. Three dimensionality of the flow is thought of as a cause for these differences. Simulations with the presence of side wall show that there is no remarkable difference of three dimensionality of the flow in terms of the variables and turbulence statistics compared to the case without side walls. However, the growth rate of shear layer and wall surface pressures matches well with that predicted using two dimensional simulations. It has been argued that this good match in shear layer growth rate occurs due to formation of oblique disturbances in presence of side walls that are considered responsible for the decrease in growth rate in 3-d mixing layers. The wall pressure match is argued to be good because of hindrance from side wall in the distribution of momentum in third direction results in higher wall pressure. The effect of dissimilar gases at large temperature difference on the growth rate reduction in compressible conditions is studied. Taking experimental conditions as baseline case, simulations are carried out for a range of convective Mach numbers. Simulations are also carried out for the same range of convective Mach numbers considering the mixing of similar gases at the same temperature. The normalized growth rates with incompressible counterpart for both the cases show that the dissimilar gas combination with large temperature difference shows higher growth rate. This result confirms earlier stability analysis that predicts increased growth rate for such cases. The growth rate reduction of a compressible mixing layer is argued to occur due to reduced pressure strain term in the Reynolds stress equation. This reduction also requires the pressure and density fluctuation correlation to be very near to unity. This holds good for a mixing layer formed between two similar gases at same temperature. For dissimilar gases at different temperatures this assumption does not hold well, and pressure-density correlation coefficient shows departure from unity. Further analysis of temperature density correlation factor, and temperature fluctuations shows that the changes in density occur predominantly due to temperature effects, than due to pressure effects. The mechanism of density variations is found to be different for similar and dissimilar gases, while for similar gases the density variations are due to pressure variations. For dissimilar gases density variation is also affected by temperature variations in addition to pressure variations. It has been observed that the traditional k-ε turbulence model within the RANS (Reynolds Averaged Navier Stokes) framework fails to capture the growth rate reduction for compressible shear layers. The performance of k-ε turbulence model is tested for the mixing of dissimilar gases at large temperature difference. For the experimental test case the shear layer growth rate and wall pressures show good match with other model free simulations. Simulations are further carried out for a range of convective Mach numbers keeping the mixing gases and their temperatures same. It has been observed that a drop in the growth rate is well predicted by RANS simulations. Further, the compressibility option has been removed and it has been observed that for the density and temperature difference, even for incompressible case, the drop in growth rate exists. This behaviour shows that the decrease in growth rate is mainly due to the interaction of temperature and species mass fraction on density. Also it can be inferred that RANS with k-ε turbulence model is able to capture the compressible shear layer growth rate for dissimilar gases at high temperature difference. The mixing of heat and species is governed by the values of turbulent Prandtl and Schmidt numbers respectively. These numbers have been observed to vary for different flow conditions, while affecting the flow field considerable in the form of temperature and species distribution. Model free simulations are carried out on an incompressible convective Mach number mixing layer, and the results are compared with that of a compressible mixing layer to study the effect of compressibility on the values of turbulent Prandtl / Schmidt numbers. It has been observed that both turbulent Prandtl and Schmidt numbers show an almost constant value in the mixing layer region for incompressible case. While, for a compressible case, both turbulent Prandtl and Schmidt numbers show a continuous variation within the mixing layer. However, the turbulent Lewis number is observed to be near unity for both incompressible and compressible cases. The thesis is composed of 8 chapters. An introduction of the subject with critical and relevant literature survey is presented in chapter 1. Chapter 2 describes the mathematical formulation and assumptions along with solution methodology needed for the simulations. Chapter 3 deals with the two and three dimensional model free simulations of the non reacting mixing layer. The effect of the presence of side wall is studied in chapter 4. Chapter 5 deals with the effect of compressibility on the mixing of two dissimilar gases at largely different temperatures. The performance of k-ε turbulence model is checked for dissimilar gases in Chapter 6. Chapter 7 is concerned with the effect of compressibility on turbulent Prandtl and Schmidt numbers. Finally concluding remarks are presented in chapter 8. The main aim of this thesis is the exploration of parallel mixing of dissimilar gases under compressible conditions for both two and three dimensional cases. The outcome of the thesis is (a) a finding that the presence of sidewall in a mixing duct does not make flow field two dimensional, instead it causes the formation of oblique disturbances and the shear layer growth rate is reduced, (b) that it has been shown that the growth rates of dissimilar gases are affected far more by large temperature difference than by compressibility as in case of similar gases, (c) that the growth rates of compressible shear layers formed between dissimilar gases are better predicted using k-εturbulence model and (d) that for compressible mixing conditions the turbulent Prandtl and Schmidt numbers vary continuously in the mixing layer region necessitating the use of some kind of model instead of assuming constant values.

This thesis presents three different approaches to model corrosion-induced crack propagation in reinforced concrete structures. The first approach is solved numerically using finite differences to model the softening behaviour of concrete in tension. The second approach idealizes the concrete cover as either a brittle elastic or an elastoplastic material so that it may be solved using a closed-form solution. Both approaches are based on a thick-walled cylinder (TWC) analogy and consider rust compressibility and rust diffusion into cracks. The third approach uses finite element modelling to validate the application of the TWC and perform a parametric study. The results obtained using each approach are compared against each other as well as against experimental results. The TWC was found to be an appropriate analogy for the geometries and reinforcement configurations considered. Analytical models were found to provide upper and lower limits to the results based on the numerical model. The experimental data found in the literature showed reasonable agreement with predictions from the numerical and elastoplastic models.

Les circuits électroniques mesurés à des températures cryogéniques permettent d'étudier le comportement quantique des électrons. En particulier, les circuits de boites quantiques sont des systèmes accordables modèles pour l'étude des électrons fortement corrélés, symbolisée par l'effet Kondo. Dans cette thèse, des circuits de boîtes quantiques à base de nanotube de carbone sont intégrés à des cavités micro-onde coplanaires, avec lesquelles l'électrodynamique quantique en cavité (cQED) a atteint un degré de contrôle remarquable de l'interaction lumière-matière. Les photons de la cavité micro-onde sont ici utilisés pour sonder la dynamique de charge dans le circuit de boîtes quantiques. Plus précisément, la cavité micro-onde de grande finesse nous a permis de mesurer la compressibilité du gas d'électrons dans une boîte avec une sensibilité sans précédent. Des mesures simultanées de transport électronique et de la compressibilité montrent que la résonance Kondo observées dans la conductance est transparente aux photons micro-ondes. Cela révèle le gel de la dynamique de charge dans la boîte quantique pour ce mécanisme particulier de transport d'électrons et illustre que la résonance Kondo à N-corps dans la conductance est associée aux corrélations issues des fluctuations de spin d'une charge gelée. Nous étudions aussi dans cette thèse la possible émergence d'une nouvelle quasi-particule, appelée état lié de Majorana, et qui serait sa propre anti-particule. Dans ce but, une grille ferromagnétique a été placée sous le nanotube pour créer un couplage spin-orbit artificiel. L'observation d'états d'Andreev dans un tel dispositif est un premier pas prometteur vers la détection avec une architecture cQED d'états liés de Majorana dans les nanotubes de carbone. / On-chip electronic circuits at cryogenic temperature are instrumental to studying the quantum behavior of electrons. In particular, quantum dot circuits represent tunable model systems for the study of strong electronic correlations, epitomized by the Kondo effect. In this thesis, carbon nanotube based-quantum dot circuits are embedded in coplanar microwave cavities, with which circuit quantum electrodynamics (cQED) has reached a high degree of control of the light-matter interaction. Here, microwave cavity photons are used to probe the charge dynamics in the quantum dot circuit. More precisely, the high finesse cavity allows us to measure the compressibility of the electron gas in the dot with an unprecedented sensitivity. Simultaneous measurements of electronic transport and compressibility show that the Kondo resonance observed in the conductance is transparent to microwave photons. This reveals the predicted frozen charge dynamics in the quantum dot for this peculiar electron transport mechanism and illustrates that the many-body Kondo resonance in the conductance is associated to correlations arising from spin fluctuations of a frozen charge. A second quantum phenomenon addressed in this thesis is the possible emergence of a new quasi-particle in condensed matter, called Majorana bound state, which would be its own anti-particle. For that purpose, a ferromagnetic gate has been placed below a nanotube in order to generate a synthetic spin-orbit coupling. The observation of Andreev bound states in such a device is a first promising step towards the detection with a cQED architecture of Majorana bound states in a carbon nanotube.

The development of numerical methods for the incompressible Navier-Stokes equations received much attention in the past 50 years. Finite element methods emerged given their robustness and reliability. In our work, we choose the P2-P1 finite element for space approximation which gives 2nd-order accuracy for velocity and 1st-order accuracy for pressure. Our research focuses on the development of several high-order semi-implicit time-stepping methods to compute unsteady flows. The methods investigated include backward difference formulae (SBDF) and defect correction strategy (DC). Using the defect correction strategy, we investigate two variants, the first one being based on high-order artificial compressibility and bootstrapping strategy proposed by Guermond and Minev (GM) and the other being a combination of GM methods with sequential regularization method (GM-SRM). Both GM and GM-SRM methods avoid solving saddle point problems as for SBDF and DC methods. This approach reduces the complexity of the linear systems at the expense that many smaller linear systems need to be solved. Next, we proposed several numerical improvements in terms of better approximations of the nonlinear advection term and high-order initialization for all methods. To further minimize the complexity of the resulting linear systems, we developed several new variants of grad-div splitting algorithms besides the one studied by Guermond and Minev. Splitting algorithm allows us to handle larger flow problems. We showed that our new methods are capable of reproducing flow characteristics (e.g., lift and drag parameters and Strouhal numbers) published in the literature for 2D lid-driven cavity and 2D flow around the cylinder. SBDF methods with grad-div stabilization terms are found to be very stable, accurate and efficient when computing flows with high Reynolds numbers. Lastly, we showcased the robustness of our methods to carry 3D computations.

Cette thèse traite des transferts pariétaux dans les écoulements turbulents supersoniques via la simulation des grandes échelles turbulentes. Des couches limites adiabatique et refroidie évoluant à Mach M∞ = 2 et à Reynolds Re0 ≈ 2600 sont considérées. Les simulations numériques utilisent un schéma split-centered d’ordre élevé pour la discrétisation des flux convectifs. Les résultats obtenus sont comparés aux simulations numériques directes (DNS) disponibles dans la littérature. Plusieurs modèles de sous-maille ont été testés et validés. Il a été montré que ces modèles exigent un minimum de raffinement de maillage afin de capturer les structures les plus énergétiques présentes en proche paroi. Les modèles montrent des performances différentes pour la distribution de la température à la paroi. Pour le cas d’une paroi refroidie, les fluctuations de température totale ne sont pas négligeables dans la région proche-paroi. Et l’anticorrélation (u’, T’) se basant sur l’hypothèse de Morkovin n’est pas satisfaite. / This work deals with spatially-evolving supersonic turbulent boundary layers over adiabatic and cold walls at M∞ = 2 and up to Re0 ≈ 2600 using 3 different SGS models. The numerical methodology is based on high-order split-centered scheme to discretize the convective fluxes of the Navier-Stokes equations . For the adiabatic case, it is demonstrated that all SGS models require a comparable minimum grid-refinement in order to capture accurately the near-wall-turbulence. Overall, the models exhibit correct behavior when predictiong the dynamic properties, but show different performances for the temperature distribution in the near-wall region. For the isothermal case, it is found that the compressibility effects are not enhanced due to the wall cooling. As expected, the total temperature fluctuations are not negligible in the near-wall region. The study shows that the anti-correlation linking both velocity and temperature fields, derived from the Morkovin's hypothesis, is not satisfied.