Parts of the work presented in this thesis have been supported by different collaboration agreements with industry partner Jaguar Land Rover Limited, Abbey Road, Whitley, Coventry CV3 4LF, UK. xvi "Good company in a journey makes the way to seem the shorter", wrote Isaak Walton back in 1653 and, certainly, I could not have wished for a better company in this journey. I would like to express my gratitude, first and foremost, to my advisor Prof. Alberto Broatch for his guidance and support in the pursuit of this research. A gratitude that I also must extend to Prof. Galindo and Dr. Navarro, not only for the development of the numerical model but for the many insightful discussions held along the development of this work. Also included in this recognition are certainly the people of the Noise Control research line, specially Prof. Torregrosa, Bernardo Planells and Josep Gómez. My sincere appreciation also goes to my colleagues at CMT-Motores Térmicos, starting with Profs. Payri and Desantes and including the professors, researchers, technicians, students, etc., with whom I shared so many good times. Special thanks as well to the administrative staff, Teresa, Amparo, Julia, for their help navigating the fearsome seas of paperwork. I also wish to thank Profs. Mats Åbom, Susann Boij and Inés López for welcoming me as a visiting researcher in the Marcus Wallenberg Laboratory at the KTH-Royal Institute of Technology, and of course to Luck, Juan Pablo, Romain, Luca, Mathieu, and the many others who offered me their hospitality in Stockholm. I am indebted as well to the people at Jaguar Land Rover with whom we have made so many fruitful collaborations. Last but not least, I wish to thank my friends and family for their everlasting support, specially my parents from whom I inherited the appreciation for mathematics and science. And finally, thank you, Paula, for sharing this journey, and those that may follow. Valencia, 2017 xvii "Hundreds of noises wove themselves into a wiry texture of sound with barbs protruding here and there, smart edges running along it and subsiding again, with clear notes splintering off and dissipating. By this noise alone, whose special quality cannot be captured in words, a man returning after years of absence would have been able to tell with his eyes shut that he was back in the Imperial Capital and Royal City of Vienna.