3-hole pressure probes are capable of accurately measuring flow angles in the yaw plane. These probes can be utilized inside a jet engine hot section for diagnostics and flow characterization. Sand and other particulate pose a significant risk to hot section components and measurement devices in gas turbine engines. The objective of this experiment was to develop a better understanding of the sensitivity of experimental 3-hole pressure probe designs to engine realistic sand fouling. In this study, Wedge, Cylindrical, and Trapezoidal probes were exposed to realistic hot section turbine environments of 1050 C at 65-70 m/s. 0-5 micron Arizona Road Dust(ARD) is heated under these conditions and used to foul the yaw probes. The sand deposited on the probe was observed to peel off the probe in thin sheets during ambient cool down. Sand fouling was assessed using a stereoscope and digital camera. Probe calibrations were performed in an ambient temperature, open air, calibration jet to mimic engine cold start conditions at Mach numbers of 0.3 and 0.5. Yaw coefficients were calculated for each probe using probe pressure and jet dynamic pressure readings. These coefficients were used to develop calibration curves for each probe initially, and again for every fouling test. Each probe performed differently, but the trends showed that the sand fouling had little impact on the probe error at Mach 0.3, and a slightly increased effect on the probe error at Mach 0.5. The experiment showed that when flow direction was determined using a true dynamic pressure reading from the jet, the probes were able to accurately measure flow direction even after being significantly sanded, some probes holes being over 50% blocked by sand accumulation. Accelerated erosion testing showed that the trapezoidal yaw probe was by far the most sensitive to sand accumulation, followed by the cylindrical probes, and the least sensitive was the wedge probe. A yaw angle range of interest was chosen to ±10 deg of yaw. The least errors from the Yaw Coefficient, as defined in this report, were found to be in the Trapezoidal and Perpendicular probe configurations. The least error found in the wedge probe. / MS / 3-hole pressure probes are used to measure the speed and direction of air and other fluid flows. These probes can be used inside an active jet engine to measure aspects of the airflow inside the engine during flight. One risk to aircraft engines is sand being ingested into the engine. This can cause significant damage to the engine as well as the hardware inside the engine. The objective of this experiment will be to determine how sand accumulation affects the performance of these probes. The experiment involved sanding the probes in a hot jet, then placing them in front of a room temperature air jet to take measurements. A microscope was used to determine how much sand was on the holes of the probe. Sand was observed to peel off naturally, as the probe cooled from the hot jet. Sand was also noticed to break off during the room temperature jet. The experiment showed that when the Jet pressures was measured from inside the jet, the probes were able to accurately measure flow direction even after being significantly sanded, <50% of the holes being blocked by sand. Of all the probes tested, the Wedge probe performed the best, though a close second was the Trapezoidal probe.

Le contexte de ces travaux de thèse est la transmission dite faster-than-Nyquist (FTN). Cette technique propose d’augmenter l’efficacité spectrale en augmentant lerythme de transmission au-delà de la bande occupée par le signal émis, indépendamment de laconstellation choisie. Il a été montré que le FTN offre des taux d’information supérieurs à ceuxdes systèmes de Nyquist. Toutefois, le non respect du critère de Nyquist entraîne l’apparitiond’interférence entre symboles et des techniques de réception appropriées doivent être utilisées.La technique de réception dite channel shortening consiste à filtrer la séquence reçue puis àcalculer des probabilités symbole a posteriori approximatives à l’aide de l’algorithme BCJRen considérant une réponse de canal modifiée, de longueur réduite. Dans la littérature, enprésence d’information a priori, les filtres du récepteur channel shortening sont optimiséssous critère de maximisation de l’information mutuelle généralisée (IMG) en utilisant desméthodes numériques. Nous proposons dans ces travaux de thèse une solution analytiquepour l’ensemble des filtres channel shortening sous critère de maximisation de l’IMG lorsquele récepteur dispose d’information a priori. Nous démontrons ensuite que l’égaliseur au sens dela minimisation de l’erreur quadratique moyenne (MMSE) est un cas particulier de l’égaliseurchannel shortening. Dans le cadre de la turbo égalisation, nous étudions ensuite un estimateurpermettant d’obtenir l’information a priori à partir de l’information en sortie du décodeurcorrecteur d’erreurs. Finalement, nous évaluons les performances du système complet aveccodage correcteur d’erreurs sur canal à bruit additif blanc Gaussien. / In order to increase the spectral efficiency of digital communications systems,the faster-than-Nyquist (FTN) approach increases the symbol rate beyond the occupied bandwidthof the transmitted signal independently of the constellation type and size. It has beenshown that information rates of FTN systems are greater than those of Nyquist systems.However, the non-compliance of the Nyquist criterion causes inter-symbol interference to appearand therefore appropriate reception techniques must be used. At reception, the channelshortening approach consists on a receiving filter followed by a BCJR algorithm computingapproximate a posteriori symbol probabilities by considering a modified channel response ofreduced length. In the literature, the channel shortening receiving filters are chosen to maximizethe generalized mutual information (GMI). Such optimization is performed by usingnumerical optimization methods. In this PhD thesis, we propose a closed-form solution forall channel shortening filters considering the GMI maximization criterion. We show that theminimum mean square error (MMSE) equalizer is a particular case of the channel shorteningapproach. Within the frame of turbo equalization, we then study a suitable estimator allowingto obtain symbols a priori information from the information provided by the a decoder. Finally,we study the performance of the complete system with channel coding over an additivewhite Gaussian noise channel.

Turbo códigos têm se tornado um importante ramo na pesquisa de codificação de canal e já foram adotados como padrão para a terceira geração de comunicação móvel. Devido ao seu alto ganho de codificação, os turbo códigos são vistos como fortes candidatos a serem adotados como padrão das futuras gerações de redes sem fio. Esse esquema de codificação é baseado na decodificação iterativa, onde decodificadores de entrada e saída suaves produzem refinamento da informação a cada iteração. Essa dissertação apresenta resultados de um estudo comparativo entre dois esquemas de codificação: turbo códigos de bloco e turbo códigos convolucionais. Os resultados mostram que os dois esquemas de codificação têm desempenho funcional complementar, sendo importante a especificação de um alvo em termos de relação sinal/ruído ou taxa de erro de bits para a escolha do esquema de codificação mais adequado. Com o mesmo modelo em linguagem de programação C foi feita uma exploração do algoritmo visando diminuição do consumo de potência. Essa exploração em parte foi feita segundo uma metodologia de exploração sistemática das possibilidades de transferência e armazenamento de dados (DTSE). Com a exploração, a redução total de consumo de potência para o armazenamento de dados foi estimada em 34%. / Turbo codes have become an important branch on channel coding research and have been adopted as standard in the third generation of mobile communication systems. Due to their high coding gain, turbo codes are expected to be part of the next generations of wireless networks standards. This coding scheme is based on iterative decoding, as soft input/soft output decoders produce an information refinement in each iteration. This dissertation shows the results of a comparative performance study of two different turbo coding schemes: block turbo codes and convolutional turbo codes. The results obtained show that the two schemes have complementary performance. It is necessary to specify a target in terms of bit error rate or signal/noise ratio. With the same C model an exploration aiming at reducing power consumption was done. Part of this exploration was done following a systematic methodology of data transfer and storage exploration (DTSE). With this exploration, a reduction of 34% on power consumption was estimated.

Turbo códigos têm se tornado um importante ramo na pesquisa de codificação de canal e já foram adotados como padrão para a terceira geração de comunicação móvel. Devido ao seu alto ganho de codificação, os turbo códigos são vistos como fortes candidatos a serem adotados como padrão das futuras gerações de redes sem fio. Esse esquema de codificação é baseado na decodificação iterativa, onde decodificadores de entrada e saída suaves produzem refinamento da informação a cada iteração. Essa dissertação apresenta resultados de um estudo comparativo entre dois esquemas de codificação: turbo códigos de bloco e turbo códigos convolucionais. Os resultados mostram que os dois esquemas de codificação têm desempenho funcional complementar, sendo importante a especificação de um alvo em termos de relação sinal/ruído ou taxa de erro de bits para a escolha do esquema de codificação mais adequado. Com o mesmo modelo em linguagem de programação C foi feita uma exploração do algoritmo visando diminuição do consumo de potência. Essa exploração em parte foi feita segundo uma metodologia de exploração sistemática das possibilidades de transferência e armazenamento de dados (DTSE). Com a exploração, a redução total de consumo de potência para o armazenamento de dados foi estimada em 34%. / Turbo codes have become an important branch on channel coding research and have been adopted as standard in the third generation of mobile communication systems. Due to their high coding gain, turbo codes are expected to be part of the next generations of wireless networks standards. This coding scheme is based on iterative decoding, as soft input/soft output decoders produce an information refinement in each iteration. This dissertation shows the results of a comparative performance study of two different turbo coding schemes: block turbo codes and convolutional turbo codes. The results obtained show that the two schemes have complementary performance. It is necessary to specify a target in terms of bit error rate or signal/noise ratio. With the same C model an exploration aiming at reducing power consumption was done. Part of this exploration was done following a systematic methodology of data transfer and storage exploration (DTSE). With this exploration, a reduction of 34% on power consumption was estimated.

Desde a última década, as autoridades aeronáuticas dos países membros da ICAO vem, gradativamente, aumentando as restrições nos níveis de ruído externo de aeronaves, principalmente nas proximidades dos aeroportos. Por isso os novos motores aeronáuticos precisam ter projetos mais silenciosos, tornando as técnicas de predição de ruído de motores cada vez mais importantes. Diferente das técnicas semi-analíticas, que vêm evoluindo nas últimas décadas, as técnicas semiempíricas possuem suas bases lastreadas em técnicas e dados que remontam à década de 70, como as desenvolvidas no projeto ANOPP. Uma bancada de estudos aeroacústicos para um conjunto rotor/estator foi construída no departamento de Engenharia Aeronáutica da Escola de Engenharia de São Carlos, permitindo desenvolver uma metodologia capaz de gerar uma técnica semi-empírica utilizando métodos e dados novos. Tal bancada é capaz de variar a rotação, o espaçamento rotor/estator e controlar a vazão mássica, resultando em 71 configurações avaliadas. Para isso, uma antena de parede com 14 microfones foi usada. O espectro do ruído de banda larga é modelado como um ruído rosa e o ruído tonal é modelado por um comportamento exponencial, resultando em 5 parâmetros: nível do ruído, decaimento linear e fator de forma da banda larga, nível do primeiro tonal e o decaimento exponencial de seus harmônicos. Uma regressão superficial Kriging é utilizada para aproximar os 5 parâmetros utilizando as variáveis do experimento e o estudo mostrou que Mach Tip e RSS são as principais variáveis que definem o ruído, assim como utilizado pelo projeto ANOPP. Assim, um modelo de previsão é definido para o conjunto rotor/estator estudado na bancada, o que permite prever o espectro em condições não ensaiadas. A análise do modelo resultou em uma ferramenta de interpretação dos resultados. Ao modelo são aplicadas 3 técnicas de validação cruzada: leave one out, monte carlo e repeated k-folds e mostrou que o modelo desenvolvido possui um erro médio, do nível do ruído total do espectro, de 2.35 dBs e desvio padrão de 0.91. / Since the last decade, the countries members of ICAO, via its aeronautical authorities, has been gradually increasing the restrictions on external aircraft noise levels, especially in the vicinity of airports. Because that, the new aero-engines need quieter designs, so noise prediction techniques for aero-engines are getting even more important. Semi-analytical techniques have undergone a major evolution since the 70th until nowadays, but semi-empirical techniques still have their bases pegged in techniques and data defined on the 70th, developed in the ANOPP project. An Aeroacoustics Fan Rig to investigate a Rotor/Stator assembly was developed at Aeronautical Engineering Department of São Carlos School of Engineering, allowing the development of a methodology capable of defining a semi-empirical technique based on new data and methods. Such rig is able to vary the rotation, the rotor/stator spacing and mass flow rate, resulting in a set of 71 configurations tested. To measure the noise, a microphone wall antenna with 14 sensors were used. The broadband noise was modeled by a pink noise and the tonal with exponential behavior, resulting in 5 parameters: broadband noise level, decay and form factor and the level and decay of tonal noise. A superficial kriging regression were used to approach the parameters using the experimental variables and the investigation has shown that Mach Tip and RSS are the most important variables that defines the noise, as well on ANOPP. A prediction model for the rotor/stator noise are defined with the 5 approximation of the parameters, that allow to predict the spectra at operations points not measured. The model analyses of the model resulted on a tool for results interpretation. Tree different cross validation techniques are applied to model: leave ou out, Monte Carlo and repeated k-folds. That analysis shows that the model developed has average error of 2.35 dBs and standard deviation of 0.91 for the spectrum level predicted.

In the nineties, two major events brought about a revolution in the field of digital communications: the invention of turbo codes and the development of multiple-input multiple-output (MIMO) wireless systems. The turbo codes are error-correcting codes which enable communication systems to operate close to the channel capacity with a reasonable complexity. Multiple-antenna transceivers, a.k.a. MIMO wireless systems, mitigate the effect of multipath fading that occurs in most terrestrial wireless communications. MIMO transmissions are more reliable than single-input single-output transmissions. Moreover, the data rate achievable by MIMO systems is also much higher. This thesis combines these two recent breakthroughs in digital communications. Iterative decoding is a key factor in the success of turbo codes. This principle has proved to be so powerful that it has soon been applied to other schemes such as iterative channel equalization, also known as turbo equalization. In the first part of this thesis, we derived a low-complexity iterative equalizer for frequency-selective MIMO channels. Its robustness against channel estimation errors was also addressed. The second part of this thesis is devoted to the estimation of the channel impulse response and the noise variance for coded transmissions over MIMO channels. We proposed several new iterative estimators based on the expectation-maximization algorithm, the expectation-conditionalmaximization algorithm and the minimum mean square error criterion. Finally, we derived lower bounds on the mean square error of channel estimators. In particular, the Cramer-Rao bound for the estimation of frequency-selective MIMO channels were computed. We mainly investigated the case where no training sequence are transmitted and the case where the receiver has a partial knowledge of the transmitted sequence.

Turboaggregat med variabel geometri har länge funnit hos automobiler, men det dröjde ända tills 2008 innan det första dök upp på ett fartyg. Syftet med denna undersökning har varit att kontrollera om de fördelar som Man B&amp;W hävdar att VTA-aggregatet skall ha stämmer, samt att undersöka om VTA-aggregatet kan lösa de problem som uppkommer i och med att man kör med reducerad fart, s.k. slowsteaming. För att undersöka detta har jag bedrivit litteraturstudie, med insamling av data mestadels från Internet. Resultatet av undersökningen visar på att ett VTA-aggregat kan minska bränsleförbrukningen och vissa emissioner vid reducerad fart jämfört med en konventionell turbo av samma storlek. Den minskade bränsleförbrukningen leder i sin tur till ekonomiska vinster. Ett VTA-aggregat lindrar också vissa av de problem som uppkommer vid slowsteaming. Med de uppgifter som kommit fram anser jag att VTA-aggregatet är praktiskt för fartyg som tillämpar slowsteaming, men att använda en VTA-turbo på ett nybyggt fartyg för att man ska slowsteama finner jag vara ett slöseri med kapital och kapacitet. / Turbocharger with variable geometry has for a longtime been used in automobiles, but it was not until 2008 that the first one appeared on a ship. The purpose of this study is to control if the benefits of the VTA-turbo claimed by Man B&amp;W are accurate and to examine if the VTA turbo does have the ability to solve the problems occurring when the ship is moving with reduced speed, so called slowsteaming. To investigate this I have conducted a literature study, with collection of data mostly from the Internet. The result of the study shows that a VTA turbo can reduce fuel consumption and emissions at reduced speed compared with a conventional turbo of the same size. The reduction in fuel consumption leads to economic gains. A VTA turbo also eases some of the problems that arise from slowsteaming. With the information received, I believe that a VTA turbo is convenient for those ships that use slow steaming. However, to use a VTA turbo on newly built ships in order to slow steam, I consider being a waste of capital and capacity.

A turbo system is driven by the excess energy in the exhaust gases.  As a result, variation in exhaust temperature cause variations in  boost pressure. By using the information about the available exhaust  energy in the turbo controller directly through a feedforward  controller, an unexpected variation in turbo boost can be avoided. A  model based controller is developed that calculates the desired  turbine power from the boost pressure reference and then, by  observing the available exhaust energy, controls the generated  turbine power to match the desired power. A Mean Value Engine Model  has been used to make simulation with the developed controller  implemented. Steps between different boost pressure references are  used to evaluate controller performance. Tests in a car have also  been made to make sure the simulation results are consistent in a  real environment. / Turbosystem drivs av överskottsenergin i motorns avgaser. Dettainnebär att temperaturvariationer i avgaserna orsakar variationer igenererad turbineffekt och därmed ökat laddtryck från turbosystemet.Används informationen om den tillgängliga energin i avgaserna när manstyr turbinen så kan man motverka oväntade laddtrycksförändringar. Idenna rapport har en modellbaserad turboregulator med en framkopplingsom beräknar en önskad turbineffekt från givet referenstryckutvecklats. Sedan tas en styrsignal fram till turbinen som, genom attanvända informationen om den observerade energin i avgaserna, matcharden önskade turbineffekten. En model av en medelvärdesmotor haranvänds för att validera prestandan i regulatorn via stegsvar mellanolika referenstryck. Det har även utförts tester i bil för att avgöraom resultatet blir detsamma under verkliga förhållanden.

Les turbo codes sont une classe de codes correcteurs d’erreurs approchant la limite théorique de capacité formulée par Claude Shannon. Conjointement à leurs excellentes performances de décodage, la complexité calculatoire modérée des turbo décodeurs a permis leur inclusion dans de nombreux standards de communications numériques. Une des métriques permettant la caractérisation de codes correcteurs d’erreurs est l’évolution du taux d’erreurs binaires en fonction du rapport signal sur bruit. Dans le cadre des turbo codes, une courbe de performance de décodage comprend deux zones principales.Dans la première zone, une faible amélioration de la qualité du canal de transmission entraîne de grandes améliorations au niveau des performances de décodage. En revanche dans la seconde, une amélioration de cette qualité ne résulte qu’en une amélioration marginale des performances de décodage. Cette seconde région est nommée zone du plancher d’erreurs. Elle peut empêcher l’utilisation de turbo codes dans des contextes nécessitant de très faibles taux d’erreurs. C’est pourquoi la communauté scientifique a proposé différentes optimisations favorisant la construction de turbo codes atténuant ce plancher d’erreurs. Cependant, ces approches ne peuvent être considérées pour des turbocodes déjà standardisés. Dans ce contexte, cette thèse adresse le problème de la réduction du plancher d’erreurs en s’interdisant de modifier la chaîne de communications numériques du côté de l’émetteur.Pour ce faire, un état de l’art de méthodes de post-traitement de décodage est dressé pour les turbo codes. Il apparaît que les solutions efficaces sont coûteuses à mettre en oeuvre car elles nécessitent une multiplication des ressources calculatoires ou impactent fortement la latence globale de décodage.Dans un premier temps, deux algorithmes basés sur une supervision de l’évolution de métriques internes aux décodeurs, sont proposés. L’un deux permet d’augmenter la convergence du turbo décodeur. L’autre ne permet qu’une réduction marginale du plancher d’erreurs. Dans un second temps, il est observé que dans la zone du plancher d’erreurs, les trames décodées par le turbo décodeur sont très proches du mot de code originellement transmis. Ceci est démontré par une proposition de prédiction analytique de la distribution du nombre d’erreurs binaires par trame erronée. Cette dernière est réalisée grâce au spectre de distance du turbo code. Puisque ces erreurs binaires responsables du plancher d’erreurs sont peu nombreuses, une métrique permettant de les identifier est mise en oeuvre. Ceci mène alors à l’établissement d’un algorithme de décodage permettant de corriger des erreurs résiduelles. Cet algorithme, appelé algorithme Flip-and-Check se base sur un principe de création de mots candidats et de vérifications successives parun code détecteur d’erreurs. Grâce à cet algorithme de décodage, un abaissement du plancher d’erreurs d’un ordre de grandeur est obtenu pour les turbo codes de différents standards (LTE, CCSDS, DVB-RCS et DVB-RCS2), ce, tout en conservant une complexité calculatoire raisonnable.Finalement, une architecture matérielle de décodage implémentant l’algorithme Flipand-Check est présentée. Une étude préalable de l’impact des différents paramètres de l’algorithme est menée. Elle aboutit à la définition de valeurs optimales pour certains de ces paramètres. D’autres sont à adapter en fonction des gains visés en terme de performances de décodage. Cette architecture démontre alors la possible intégration de cet algorithme aux turbo décodeurs existants ; permettant alors d’abaisser le plancher d’erreurs des différents turbo codes présents dans les différents standards de télécommunication. / Since their introduction in the 90’s, turbo codes are considered as one of the most powerful error-correcting code. Thanks to their excellent trade-off between computational complexity and decoding performance, they were chosen in many communication standards. One way to characterize error-correcting codes is the evolution of the bit error rate as a function of signal-to-noise ratio (SNR). The turbo code error rate performance is divided in two different regions : the waterfall region and the error floor region. In the waterfall region, a slight increase in SNR results in a significant drop in error rate. In the error floor region, the error rate performance is only slightly improved as the SNR grows. This error floor can prevent turbo codes from being used in applications with low error rates requirements. Therefore various constructions optimizations that lower the error floor of turbo codes has been proposed in recent years by scientific community. However, these approaches can not be considered for already standardized turbo codes.This thesis addresses the problem of lowering the error floor of turbo codes without allowing any modification of the digital communication chain at the transmitter side. For this purpose, the state-of-the-art post-processing decoding method for turbo codes is detailed. It appears that efficient solutions are expensive to implement due to the required multiplication of computational resources or can strongly impact the overall decoding latency. Firstly, two decoding algorithms based on the monitoring of decoder’s internal metrics are proposed. The waterfall region is enhanced by the first algorithm. However, the second one marginally lowers the error floor. Then, the study shows that in the error floor region, frames decoded by the turbo decoder are really close to the word originally transmitted. This is demonstrated by a proposition of an analytical prediction of the distribution of the number of bits in errors per erroneous frame. This prediction rests on the distance spectrum of turbo codes. Since the appearance of error floor region is due to only few bits in errors, an identification metric is proposed. This lead to the proposal of an algorithm that can correct residual errors. This algorithm, called Flip-and-Check, rests on the generation of candidate words, followed by verification according to an error-detecting code. Thanks to this decoding algorithm, the error floor of turbo codes encountered in different standards (LTE, CCSDS, DVB-RCS and DVB-RCS2) is lowered by one order of magnitude. This performance improvement is obtained without considering an important computational complexity overhead. Finally, a hardware decoding architecture implementing the Flip-and-Check algorithm is presented. A preliminary study of the impact of the different parameters of this algorithm is carried out. It leads to the definition of optimal values for some of these parameters. Others has to be adapted according to the gains targeted in terms of decoding performance. The possible integration of this algorithm along with existing turbo decoders is demonstrated thanks to this hardware architecture. This therefore enables the lowering of the error floors of standardized turbo codes.

Desde a última década, as autoridades aeronáuticas dos países membros da ICAO vem, gradativamente, aumentando as restrições nos níveis de ruído externo de aeronaves, principalmente nas proximidades dos aeroportos. Por isso os novos motores aeronáuticos precisam ter projetos mais silenciosos, tornando as técnicas de predição de ruído de motores cada vez mais importantes. Diferente das técnicas semi-analíticas, que vêm evoluindo nas últimas décadas, as técnicas semiempíricas possuem suas bases lastreadas em técnicas e dados que remontam à década de 70, como as desenvolvidas no projeto ANOPP. Uma bancada de estudos aeroacústicos para um conjunto rotor/estator foi construída no departamento de Engenharia Aeronáutica da Escola de Engenharia de São Carlos, permitindo desenvolver uma metodologia capaz de gerar uma técnica semi-empírica utilizando métodos e dados novos. Tal bancada é capaz de variar a rotação, o espaçamento rotor/estator e controlar a vazão mássica, resultando em 71 configurações avaliadas. Para isso, uma antena de parede com 14 microfones foi usada. O espectro do ruído de banda larga é modelado como um ruído rosa e o ruído tonal é modelado por um comportamento exponencial, resultando em 5 parâmetros: nível do ruído, decaimento linear e fator de forma da banda larga, nível do primeiro tonal e o decaimento exponencial de seus harmônicos. Uma regressão superficial Kriging é utilizada para aproximar os 5 parâmetros utilizando as variáveis do experimento e o estudo mostrou que Mach Tip e RSS são as principais variáveis que definem o ruído, assim como utilizado pelo projeto ANOPP. Assim, um modelo de previsão é definido para o conjunto rotor/estator estudado na bancada, o que permite prever o espectro em condições não ensaiadas. A análise do modelo resultou em uma ferramenta de interpretação dos resultados. Ao modelo são aplicadas 3 técnicas de validação cruzada: leave one out, monte carlo e repeated k-folds e mostrou que o modelo desenvolvido possui um erro médio, do nível do ruído total do espectro, de 2.35 dBs e desvio padrão de 0.91. / Since the last decade, the countries members of ICAO, via its aeronautical authorities, has been gradually increasing the restrictions on external aircraft noise levels, especially in the vicinity of airports. Because that, the new aero-engines need quieter designs, so noise prediction techniques for aero-engines are getting even more important. Semi-analytical techniques have undergone a major evolution since the 70th until nowadays, but semi-empirical techniques still have their bases pegged in techniques and data defined on the 70th, developed in the ANOPP project. An Aeroacoustics Fan Rig to investigate a Rotor/Stator assembly was developed at Aeronautical Engineering Department of São Carlos School of Engineering, allowing the development of a methodology capable of defining a semi-empirical technique based on new data and methods. Such rig is able to vary the rotation, the rotor/stator spacing and mass flow rate, resulting in a set of 71 configurations tested. To measure the noise, a microphone wall antenna with 14 sensors were used. The broadband noise was modeled by a pink noise and the tonal with exponential behavior, resulting in 5 parameters: broadband noise level, decay and form factor and the level and decay of tonal noise. A superficial kriging regression were used to approach the parameters using the experimental variables and the investigation has shown that Mach Tip and RSS are the most important variables that defines the noise, as well on ANOPP. A prediction model for the rotor/stator noise are defined with the 5 approximation of the parameters, that allow to predict the spectra at operations points not measured. The model analyses of the model resulted on a tool for results interpretation. Tree different cross validation techniques are applied to model: leave ou out, Monte Carlo and repeated k-folds. That analysis shows that the model developed has average error of 2.35 dBs and standard deviation of 0.91 for the spectrum level predicted.