Selectively-transparent and conducting photonic crystals (STCPCs) made of alternating layers of sputtered indium-tin oxide (ITO) and spin-coated silica (SiO2) nanoparticle films have potential applications in micromorph solar cells and building integrated photovoltaics (BIPVs). In this work, theoretical calculations have been performed to show performance enhancement of the micromorph solar cell upon integration of the STCPC an intermediate reflector. Thin semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells with STCPC rear contacts are demonstrated in proof-of-concept devices. A 10% efficiency increase in a 135nm thick a-Si:H cell on an STCPC reflector with Bragg peak at 620nm was observed, while the transmitted solar irradiance and illuminance are determined to be 295W/m2 and 3480 lux, respectively. The STCPC with proper Bragg peak positioning can boost the a-Si:H cell performance while transmitting photons that can be used as heat and lighting sources in building integrated photovoltaic applications.

A searched for narrow-band-noise (NBN) modulations of the infrared transmission in blue bronze has been performed. No modulations were observed, giving an upper limits for NBN changes in the absorption coefficient of )2000/(/3.0.andlt;.cmNBN. The implication of these results on proposed CDW properties and NBN mechanisms are discussed. An infrared microscope with a capability of doing both reflectance and transmission measurements has been integrated into the previous electro-transmission system with tunable diode lasers. Electro-optic experiments were done using the microscope for the studies of the CDW states of K0.3MoO3 (blue bronze) and orthorhombic TaS3. The electro-reflectance signal for blue bronze has been evidenced for the first time. The infrared reflectance of K0.3MoO3 varied with position when a voltage greater than the CDW depinning threshold is applied. The spatial dependence of .R/R was slightly different than for ./, in that the magnitude of .R/R decreased and, for low voltages and frequencies, the signal became inverted near the contacts. Perhaps the differences might be associated with changes in the CDW properties on the surface. For blue bronze, the electro-reflectance signal was measured to be smaller than electro-transmittance signal by one order of magnitude for light polarized transverse to the chain direction, while the electro-reflectance signal for parallel polarized light was found to be a few times smaller than for transverse polarized light. The fits of the electro-reflectance spectrum showed that the changes in background dielectric constant were ~ 0.05 % and/or oscillator strength and/or frequency shifts of the phonons were ~ 0.05 % and ~ 0.005 cm-1 in the applied electric field. We also found that parallel polarized phonons are affected by CDW strain, and these changes dominate the electro-reflectance spectrum. We have examined the electro-reflectance spectra associated with CDW current investigation for light polarized parallel to the conducting chains for signs of expected current-induced intragap states, and conclude that the density of any such states is at most a few times less than expected. We have observed a large (~1%) change in infrared reflectance of orthorhombic TaS3, when its CDW is depinned. The change is concentrated near one current contact. Assuming that the change in reflectance is proportional to the degree of CDW polarization, we have studied the dynamics of CDW repolarization through position dependent measurements of the variation of the electro-reflectance with the frequency of square wave voltages applied to the sample, and have found that the response could be characterized as a damped harmonic oscillator with a distribution of relaxation (i.e. damping) times. The average relaxation time, which increases away from the contacts, varies with applied voltage as with p ~ 3/2, but the distribution of times broadens as the voltage approaches the depinning threshold. Very low resonant frequencies (~ 1 kHz) indicate a surprisingly large amount of inertia, which is observable in the time dependence of the change in reflectance as a polarity dependent delay of ~ 100 s.

An important part of mathematics is the construction of good definitions. Some things, like planar graphs, are trivial to define, and other concepts, like compact sets, arise from putting a name on often used requirements (although the notion of compactness has changed over time to be more general). In other cases, such as in set theory, the natural definitions may yield undesired and even contradictory results, and it can be necessary to use a more complicated formalization.    The notion of a curve falls in the latter category. While it is intuitively clear what a curve is – line segments, empty geometric shapes, and squiggles like this: – it is not immediately clear how to make a general definition of curves. Their most obvious characteristic is that they have no width, so one idea may be to view curves as what can be drawn with a thin pen. This definition, however, has the weakness that even such a line has the ability to completely fill a square, making it a bad definition of curves. Today curves are generally defined by the condition of having no width, that is, being one-dimensional, together with the conditions of being compact and connected, to avoid strange cases.    In this thesis we investigate this definition and a few examples of curves.

In this thesis, we present solutions to several problems concerning one-dimensi- onal continua. We give an inductive description of graphs with a given disconnec- tion number, this answers a question of S. B. Nadler. Further, we state a topo- logical characterization of the Sierpi'nski triangle. In the study of shore sets in dendroids and λ-dendroids we obtain several positive results and we also provide some counterexamples. By doing this, we continue in the recent work of several authors. We are also dealing with the notion of 1 2 -homogeneity and we prove that up to homeomorphism there are only two 1 2 -homogeneous chainable continua with just two end points. We present also a new elegant proof of a classical theorem of Waraszkiewicz. 1

Orientador: Milton Lahuerta / Banca: Vera Alves Cepeda / Banca: Robespierre de Oliveira / Banca: Luiz Antonio Calmon Nabuco Latória / Banca: Luis Fernando Ayerbe / Resumo: Este trabalho pretende investigar a formação do conceito de Warfare State, traduzido para o português como Estado Militarista (no livro de F.J.Cook) e como "Estado beligerante" (no livro A ideologia da sociedade industrial. O homem unidimensional de Herbert Marcuse.) A pesquisa tenta mostrar como Cook formulou originalmente tal conceito e como ele foi configurado em sua obra, a fim de mostrar, em seguida, como H Marcuse se apropriou dele em sua obra para conceber uma das dimensões da sociedade unidimensional. Após a análise comparativa das duas obras e do confronto entre elas, que as esclarece mutuamente, a pesquisa tentará ainda mostrar tanto como deve ser entendido o conceito de sociedade unidimensional quanto à atualidade do conceito de Estado Beligerante. / Abstract: This research studies the nature and the history of the concept The Warfare State in the book The Warfare State, writing by Fred J.Cook in 1962 and in the book of Herbert Marcuse One dimensional-man, writing in 1964. / Doutor

Ferromagnetismo itinerante permanece um problema elusivo em Física. O fenômeno resulta da competição entre interação eletrônica e efeitos de muitos corpos e não pode ser tratado perturbativamente. Particularmente em uma dimensão, teoremas proíbem fases ferromagnéticas em T = 0 para modelos de rede com hopping de primeiros vizinhos. Nos últimos vinte anos, entretanto, apareceram modelos na literatura que estendem o hopping para além de primeiros vizinhos e para os quais ordem ferromagnética foi rigorosamente estabelecida. Praticamente todas as demonstrações da existência de ferromagnetos unidimensionais são feitas em fase isolante (com exceção de casos patológicos, como repulsão infinita). Isto nos levou a investigar o acoplamento entre os setores de spin e carga no regime fortemente interagente quando se dopa o sistema, o que introduz pontos de Fermi pF e -pF. Encontramos, com teoria de perturbação, singularidades logarítmicas na autoenergia do mágnon quando seu momentum é pF ou -pF. Derivamos uma teoria de campo efetiva para o espalhamento em torno desses pontos entre os mágnons e férmions sem spin (que representam o setor de carga). O modelo efetivo é similar ao modelo Kondo, que consiste de uma impureza magnética localizada acoplada localmente com um mar fermiônico por uma interação de troca entre spins. Em nosso modelo, há, na realidade, um pseudospin que indica se o momentum de uma partícula é próximo de pF ou de -pF e o mágnon se comporta como uma impureza móvel. A mobilidade da impureza leva a uma relação de dispersão para os férmions dependente do pseudospin da impureza. / Itinerant ferromagnetism remains an elusive problem in Physics. The phenomenon arises from a competition between electronic interaction and many-body effects and cannot be treated perturbatively. Particularly in 1D, there are rigorous proofs that forbid ferromagnetic phase for lattice models with nearest-neighbours hopping only. In the last twenty years, however, models with hopping beyond nearest-neighbours were proposed in the literature and for which ferromagnetic phase was rigorously established. Virtually every proof of the existence of one-dimensional ferromagnets is done in an insulator phase (disregarding some pathological cases, such as infinite electronic repulsion). That motivated us to investigate the coupling between spin and charge sectors in the strongly interacting regime when we dope the system, introducing two Fermi points, pF and -pF. We found out, through perturbation theory, logarithmic singularities in the magnon selfenergy when its momentum is pF or -pF. To understand them, we derived an effective field theory for the scattering between magnons and spinless fermions (which represent the charge sector) close to these points. The effective model resembles the Kondo model, which describes a magnetic impurity locally coupled to a fermionic sea through spin exchange interaction. In our model, there is actually a pseudospin that indicates if a particle momentum is closest to pF or -pF and the magnon behaves as a mobile impurity. The impurity mobility leads to a fermionic dispersion relation that depends on the impurity pseudospin.

No description available.

The finite difference time domain (FDTD) method is commonly used for numerical simulations of the electromagnetic wave propagation in time domain. The FDTD method is easy to implement and the computational results are highly relevant to the analytical solution, so that the FDTD method is applied to variety application problems. However, the computational efficiency of the FDTD method is constrained by the upper limit of the temporal discretisation. The Courant Friedrich Lewy (CFL) stability condition limits the time step for the computation of the FDTD method, so that if the spatial discretisation of the computation is set to be small in order to obtain high accurate results, the size of the temporal discretisation need to be satisfy the CFL stability condition. The locally one dimensional FDTD (LOD-FDTD) method is unconditionally stable. The time step and the spatial step can be independently chosen for the computation of the LOD-FDTD method. The arithmetic operations of the LOD-FDTD method is fewer than that of the other implicit FDTD method, such as the Crank Nicolson FDTD (CN-FDTD) method and the alternating direction implicit FDTD (ADI-FDTD) method. Although the implementation of the LOD-FDTD method is simpler than that of the ADI-FDTD method,the numerical error in the computational results of the LOD-FDTD method is equivalent to that in the computational results of the ADI-FDTD method. In this thesis, a new three dimensional (3D) frequency dependent (FD) LOD-FDTD method is proposed. The one pole Debye model is incorporated into the 3D-FD-LOD-FDTD method in order to deal with practical applications. The proposed method is implemented in Fortran 90 and parallelised with OpenMP. A simulation model of the human phantom is developed in the 3D-FD-LOD-FDTD method with fine structures and frequency dependent dielectric properties of the human tissues, and numerical simulation of electromagnetic wave propagation inside the human head is shown.

Low fuel consumption is one of the main requirement for current internal combustion engines for passenger car applications. One of the most used strategies to achieve this goal is to use downsized engines (smaller engines while maintaining power) what implies the usage of turbochargers. The coupling between both machines (the turbocharger and the internal combustion engines) presents many difficulties due to the different nature between turbomachines and reciprocating machines. These difficulties make the optimal design of the turbocharged internal combustion engines a complicated issue. In these thesis a strong effort has been made to improve the global understanding of different physical phenomena occurring in turbochargers and in turbocharged engines. The work has been focused on the 1D modelling of the phenomena since 1D tools currently play a major role in the engine design process. Both experimental and modelling efforts have been made to understand the heat transfer and gas flow processes in turbochargers. Previously to the experimental analysis a literature review has been made in which the state of the art of heat transfer and gas flow modelling in turbochargers have been analysed. The experimental effort of the thesis has been focused on measuring different turbochargers in the gas stand and the engine test bench. In the first case, the gas stand, a more controlled environment, has been used to perform tests at different conditions. Hot tests with insulated and not insulated turbocharger have been made to characterise the external heat transfer. Moreover, adiabatic tests have been made to compare the effect of the heat transfer on different turbocharger variables and for the validation of the turbine gas flow models. In the engine test bench full and partial load tests have been made for model validation purposes. For the models development task, the work has been divided in heat flow models and gas flow models. In the first case, a general heat transfer model for turbochargers has been proposed based on the measured turbochargers and data available from previous works of the literature. This model includes a procedure of conductive conductances estimation, internal and external convection correlations and radiation estimation procedure. In the case of the gas flow modelling, an extended model for VGT performance maps extrapolation for both the efficiency and the mass flow has been developed as well as a model for discharge coefficient prediction in valves for two stage turbochargers. Finally, the models have been fully validated coupling them with a 1D modelling software simulating both the gas stand and the whole engine. On the one hand, the results of the validation show that compressor and turbine outlet temperature prediction is highly improved using the developed models. This results prove that the turbocharger heat transfer phenomena are important not only for partial load and transient simulation but also in full loads. On the other hand, the VGT extrapolation model accuracy is high even at off-design conditions. / El bajo consumo de combustible es uno de los principales requerimientos de los motores de combustión interna actuales para aplicaciones de coches de pasajeros. Una de las estrategias más usadas para conseguir ese fin es el uso de motores "downsized" (motores más pequeños con la misma potencia) lo que implica el uso de turbocompresores. El acoplamiento entre ambas máquinas (el turbocompresor y el motor de combustión alternativo) presenta muchas dificultades debido a la diferente naturaleza entre las turbomáquinas y las máquinas alternativas. Estas dificultades convierten el diseño óptimo de los motores de combustión interna sobrealimentados en un asunto complicado. En esta tesis se ha realizado un importante esfuerzo para mejorar el entendimiento global de los diferentes fenómenos físicos que ocurren en los turbocompresores y en los motores sobrealimentados. El trabajo se ha centrado en el modelado 1D de los fenómenos puesto que las herramientas 1D juegan actualmente un papel principal en el proceso de diseño del motor. Se han realizado tanto esfuerzos experimentales como de modelado para el entendimiento de los procesos de transmisión de calor y de flujo de gases en turbocompresores. Previamente al análisis experimental se ha realizado una revisión de la literatura disponible en la que se ha analizado el estado del arte del modelado de transmisión de calor y flujo de gases en turbocompresores. El esfuerzo experimental de la tesis se ha centrado en la medida de diferentes turbocompresores en el banco de gas y en el banco motor. En el primer caso, se ha utilizado el banco de gas, un ambiente más controlado, para realizar ensayos en diferentes condiciones. Se han realizado ensayos calientes con y sin aislamiento del turbocompresor para caracterizar el flujo de calor externo. Además, se han realizado ensayos adiabáticos para comparar el efecto de la transmisión de calor sobre diferentes variables del turbocompresor y para la validación de los modelos de flujo de gases de la turbina. En el banco motor se han realizado ensayos a plena carga y a cargas parciales para usarlos en la validación. Para la tarea del desarrollo de los modelos, el trabajo se dividió en modelos de flujo de calor y modelos de flujo de gases. En el primer caso, se ha propuesto un modelo general de transmisión de calor para turbocompresores basado en los turbocompresores medidos y en datos disponibles de trabajos previos de la literatura. Este modelo incluye un procedimiento para la estimación de las conductancias conductivas, correlaciones de convección interna y externa y un procedimiento de estimación de la radiación. En el caso del modelado de flujo de gases, se ha desarrollado un modelo extendido para la extrapolación de mapas de funcionamiento de TGV tanto para el rendimiento como para el gasto másico además del modelo de predicción de coeficientes de descarga en válvulas de turbocompresores de doble etapa. Finalmente, los modelos han sido completamente validados con su acoplamiento a un software de modelado 1D simulando tanto el banco de turbos como el motor completo. Por un lado, los resultados de la validación señalan que la predicción de las temperaturas de salida de compresor y turbina mejora notablemente usando los modelos desarrollados. Este resultado demuestra que los fenómenos de transmisión de calor son importantes no sólo en simulaciones de cargas parciales y de transitorios sino también en plenas cargas. Por otro lado, la precisión del modelo de extrapolación de TGV es alta incluso en condiciones fuera de diseño. / El baix consum de combustible és un dels principals requeriments dels motors de combustió interna actuals per a aplicacions de cotxes de passatgers. Una de les estratègies més usades per a aconseguir eixe fi és l'ús de motors "downsized" (motors més xicotets amb la mateixa potència) el que implica l'ús de turbocompressors. L'adaptament entre ambdues màquines (el turbocompressor i el motor de combustió alternatiu) presenta moltes dificultats degut a la diferent naturalesa entre les turbomàquines i les màquines alternatives. Estes dificultats convertixen el disseny òptim dels motors de combustió interna sobrealimentats en un assumpte complicat. En esta tesi s'ha realitzat un important esforç per a millorar l'enteniment global dels diferents fenòmens físics que ocorren en els turbocompressors i en els motors sobrealimentats. El treball s'ha centrat en el modelatge 1D dels fenòmens ja que les ferramentes 1D juguen actualment un paper principal en el procés de disseny del motor. S'han realitzat tant esforços experimentals com de modelatge per a l'enteniment dels processos de transmissió de calor i de flux de gasos en turbocompressors. Prèviament a l'anàlisi experimental s'ha realitzat una revisió de la literatura disponible en què s'ha analitzat l'estat de l'art del modelatge de transmissió de calor i flux de gasos en turbocompressors. L'esforç experimental de la tesi s'ha centrat en la mesura de diferents turbocompressors en el banc de gas i en el banc motor. En el primer cas, s'ha utilitzat el banc de gas, un ambient més controlat, per a realitzar assajos en diferents condicions. S'han realitzat assajos calents amb i sense aïllament del turbocompressor per a caracteritzar el flux de calor extern. A més, s'han realitzat assajos adiabàtics per a comparar l'efecte de la transmissió de calor sobre diferents variables del turbocompressor i per a la validació dels models de flux de gasos de la turbina. En el banc motor s'han realitzat assajos a plena càrrega i a càrregues parcials per a usar-los en la validació. Per a la tasca del desenvolupament dels models, el treball es va dividir en models de flux de calor i models de flux de gasos. En el primer cas, s'ha proposat un model general de transmissió de calor per a turbocompressors basat en els turbocompressors mesurats i en dades disponibles de treballs previs de la literatura. Este model inclou un procediment per a l'estimació de les conductàncies conductivas, correlacions de convecció interna i externa i un procediment d'estimació de la radiació. En el cas del modelatge de flux de gasos, s'ha desenvolupat un model estés per a l'extrapolació de mapes de funcionament de TGV tant per al rendiment com per al gasto màssic a més del model de predicció de coeficients de descàrrega en vàlvules de turbocompressors de doble etapa. Finalment, els models han sigut completament validats amb el seu adaptament a un software de modelatge 1D simulant tant el banc de turbos com el motor complet. D'una banda, els resultats de la validació assenyalen que la predicció de les temperatures d'eixida de compressor i turbina millora notablement usant els models desenrotllats. Este resultat demostra que els fenòmens de transmissió de calor són importants no sols en simulacions de càrregues parcials i de transitoris sinó també en plenes càrregues. D'altra banda, la precisió del model d'extrapolació de TGV és alta inclús en condicions fora de disseny. / Dombrovsky, A. (2017). Synthesis of the 1D modelling of turbochargers and its effects on engine performance prediction [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/82307 / TESIS

[ES] Está fuera de toda duda que la industria del automóvil está viviendo una profunda transformación que, durante los últimos años, ha progresado a un ritmo acelerado. Debido a la crecientemente estricta regulación sobre emisiones contaminantes y la necesidad de satisfacer la siempre creciente demanda de movilidad sostenible, es necesario que los motores de combustión modernos reduzcan su consumo y emisiones manteniendo el rendimiento del motor. Para enfrentarse a este desafío, los ingenieros de investigación y desarrollo han redoblado sus esfuerzos a la hora de diseñar y mejorar los modelos unidimensionales, hasta el punto en el que el desarrollo de modelos 1D así como la simulación juegan un papel fundamental en los primeras etapas de diseño de nuevos motores y tecnologías. Al mismo tiempo, la tecnología de turbosobrealimentación se ha consolidado como una de las más efectivas a la hora de construir motores de alta eficiencia, lo que ha hecho evidente la importancia de comprender y modelar correctamente los efectos asociados a los turbogrupos. Particularmente, los fenómenos que ocurren en la turbina en condiciones de flujo fuertemente pulsante han demostrado ser complicadas de modelar y sin embargo decisivas, ya que los códigos de simulación son especialmente útiles cuando son diseñados para trabajar en condiciones realistas. Este trabajo se centra en mejorar los modelos unidimensionales actuales así como en desarrollar nuevas soluciones con el objetivo de contribuir a una mejor predicción del comportamiento de la turbina sometida a condiciones de flujo pulsante. Tanto los esfuerzos realizados en los trabajos experimentales como en los de modelado se han producido para poder proporcionar métodos que sean fáciles de adaptar a las diferentes configuraciones de turbogrupo usadas en la industria, por ello, pueden ser aplicados por ejemplo en turbinas de entrada simple y también en las cada vez más usadas turbinas de entrada doble. En cuanto al trabajo de modelado en la parte de turbina de entrada simple, el foco se ha puesto en presentar una versión mejorada de un código quasi-2D. La validación del modelo se basa en los datos experimentales que están disponibles de trabajos enteriores de la literatura, proporcionando una comparación completa entre los modelos quasi-2D y el clásico modelo 1D. La presión a la entrada y salida de la turbina se ha descompuesto en ondas que viajan hacia delante y hacia atrás por medio de la descomposición de presiones, empleando la componente reflejada y transmitida para verificar la bondad del modelo. El trabajo experimental de esta tesis se centra en desarrollar un nuevo método para ensayar cualquier turbina de doble entrada sometida a condiciones de flujo fuertemente pulsante. La configuración del banco de gas se ha diseñado para ser suficientemente flexible como para realizar pulsos en las dos ramas de entrada por separado, así como para usar condiciones de flujo caliente o condiciones ambiente con mínimos cambios en la instalación. La campaña experimental se usa para validar un modelo integrado unidimensional de turbina tipo twin scroll con especial foco en las componentes reflejada y transmitida para analizar el desempeño del modelo su capacidad de predicción de la acústica no lineal. Finalmente, después de desarrollar el trabajo experimental y de modelado, se presenta un procedimiento para caracterizar el sonido y ruido de la turbina por medio de matrices de transferencia acústica que es comparado con el código unidimensional completo. En este sentido, el método proporciona una herramienta útil y fácil de implementar para simulaciones en tiempo real que aplica de una manera práctica el trabajo de modelado expuesto a lo largo de esta tesis. / [CAT] Està fora de tot dubte que la indústria de l'automòbil està vivint una profunda transformació que, durant els últims anys, ha progressat a un ritme accelerat. A causa de la creixentment estricta regulació sobre emissions contaminants i la necessitat de satisfer la sempre creixent demanda de mobilitat sostenible, és necessari que els motors de combustió moderns reduïsquen el seu consum i emissions mantenint el rendiment del motor. Per a enfrontar-se a aquest desafiament, els enginyers de recerca i desenvolupament han redoblat els seus esforços a l'hora de dissenyar i millorar els models unidimensionals, fins al punt en el qual el desenvolupament de models 1D així com la simulació juguen un paper fonamental en les primeres etapes de disseny de nous motors i tecnologies. Al mateix temps, la tecnologia de turbosobrealimentación s'ha consolidat com una de les més efectives a l'hora de construir motors d'alta eficiència, la qual cosa ha fet evident la importància de comprendre i modelar correctament els efectes associats als turbogrupos. Particularment, els fenòmens que ocorren en la turbina en condicions de flux fortament polsant han demostrat ser complicades de modelar i no obstant això decisives, ja que els codis de simulació són especialment útils quan són dissenyats per a treballar en condicions realistes. Aquest treball se centra en millorar els models unidimensionals actuals així com a desenvolupar noves solucions amb l'objectiu de contribuir a una millor predicció del comportament de la turbina sotmesa a condicions de flux polsant. Tant els esforços realitzats en els treballs experimentals com en els de modelatge s'han produït per a poder proporcionar mètodes que siguen fàcils d'adaptar a les diferents configuracions de turbogrupo usades en l'indústria, per això, poden ser aplicats per exemple en turbines d'entrada simple i també en les cada vegada més usades turbines d'entrada doble. Pel que fa al treball de modelatge en la part de turbina d'entrada simple, el focus s'ha posat a presentar una versió millorada d'un codi quasi-2D. La validació del model es basa en les dades experimentals que estan disponibles de treballs anteriors de la literatura, proporcionant una comparació completa entre els models quasi-2D i el clàssic model 1D. La pressió a l'entrada i eixida de la turbina s'ha descompost en ones que viatgen cap avant i cap enrere per mitjà de la descomposició de pressions, emprant la component reflectida i transmesa per a verificar la bondat del model. El treball experimental d'aquesta tesi se centra en desenvolupar un nou mètode per a assajar qualsevol turbina de doble entrada sotmesa a condicions de flux fortament pulsante. La configuració del banc de gas s'ha dissenyat per a ser prou flexible com per a realitzar polsos en les dues branques d'entrada per separat, així com per a usar condicions de flux calent o condicions ambient amb mínims canvis en la instal·lació. La campanya experimental s'usa per a validar un model integrat unidimensional de turbina tipus twin-scroll amb especial focus en les components reflectida i transmesa per a analitzar l'acompliment del model la seua capacitat de predicció de l'acústica no lineal. Finalment, després de desenvolupar el treball experimental i de modelatge, es presenta un procediment per a caracteritzar el so i soroll de la turbina per mitjà de matrius de transferència acústica que és comparat amb el codi unidimensional complet. En aquest sentit, el mètode proporciona una eina útil i fàcil d'implementar per a simulacions en temps real que aplica d'una manera pràctica el treball de modelatge exposat al llarg d'aquesta tesi. / [EN] It is beyond all doubt that the automotive industry is living a deep transformation that, during the last years, has progressed at an ever accelerating rate. Due to the increasingly stringent pollutant emission regulations and the necessity to fulfil an ever growing demand for sustainable mobility, the modern internal combustion engines are required to strongly reduce the fuel consumption and emissions, while keeping the engine performance. In order to confront this challenge, engine research and development engineers have redoubled their efforts in designing and improving one-dimensional codes, to the point that the development of 1D models and simulation campaigns play a major role in the early steps of designing new engines or technologies. At the same time as the turbocharging technology has arisen as one of the most effective and extended solutions for building high efficient engines, the importance of understanding and modelling correctly the turbocharger effects has become evident. In particular, the phenomena that occurs in the turbine under highly pulsating conditions have proven to be challenging to model and yet decisive, as simulation codes are especially useful when they are designed to work under realistic conditions. This work focusses on the improvement of current one-dimensional models as well as in the development of new solutions with the aim of contributing to a better prediction of the turbine performance under pulsating conditions. Both experimental and modelling efforts have been made in order to provide methods that are easily adaptable to different turbocharger configurations used in the industry, so they can be applied for example in single turbines and also in the increasingly used two-scroll turbine technology. Regarding the modelling work of the single entry turbine part, the work has been focused in presenting an improved version of a quasi-2D code. The validation of the model is based on the experimental data available from previous works of the literature, providing a complete comparison between the quasi-2D and a classic 1D model. By means of a pressure decomposition, the pressure at the turbine inlet and outlet has been split into forward and backward travelling waves, employing the reflected and transmitted components to verify the goodness of the model. The experimental work of the thesis is centred in developing a new method in order to test any two-scroll turbine under highly pulsating flow conditions. The gas stand setup has been designed to be flexible enough to perform pulses in both inlet branches separately as well as to use hot or ambient conditions with minimal changes in the installation. The experimental campaign is used to fully validate an integrated 1D twin-scroll turbine model with special focus in the reflected and transmitted components for analysing the performance of the model and its non-linear acoustics prediction capabilities. Finally, after the experiment and modelling work is developed, a procedure to characterise the turbine sound and noise by means of acoustic transfer matrices is presented and tested against the fully one-dimensional code. In this sense, this method provides a useful and easily-implementable tool for fast and real time simulations that applies in a practical way the modelling work exposed along this thesis. / Soler Blanco, P. (2020). Simulation and modelling of the performance of radial turbochargers under unsteady flow [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/141609 / TESIS