Unlock the potential of computational fluid dynamics with this essential guide for master's and graduate students, and researchers. It explores the immersed boundary method (IBM), a revolutionary approach for simulating flows in complex geometries. With a focus on fluid/structure interaction, it examines theoretical principles and practical implementations, offering insights into tackling intricate geometries and enhancing simulation accuracy. The book features a series of numerical examples that increase in complexity, and is accompanied by the source code, allowing readers to replicate results and deepen their understanding. Whether you're wanting to refine your skills or embark on new research, this introduction will empower you to master the art of complex flow simulations.