PML Methods for Aero Acoustics Computations

Two well-posed non-reflecting boundary conditions of PML type for the linearized Euler equations are examined and compared. The efficiency of these boundary conditions are evaluated for circular waves as well as plane waves with different angles of incidence, and the results are compared with characteristic boundary conditions as a reference. PML Metoder för Aeroakustiska Beräkninger Sammanfattning Två icke-reflekterande randvillkor av PML-typ för den linjäriserade Euler ekvationen studeras och jämförs. Effektiviteten hos dessa randvillkor undersöks för cirkulära vågor liksom för plana vågor med olika infallsvinklar och, som en referens, jämförs resultaten med karakteristiska randvillkor. Acknowledgments First I would like to thank my supervisor, Gunilla Kreiss, for her skillful guidance and insightful comments and advice, Daniel Apellö, who could not have helped me more, Olof Runborg who answered my questions patiently , and Jesper Oppelstrup, who introduced this subject to me. I would also like to thank all my friends at NADA, especially Yuan Lin and Anna Dzougoutov who helped me alot. Last I would like to thank my family, especially my mother, Parvaneh, who her encouragement was the main reason to complete this thesis.