Multiphase flows refer to the flows with distinctively different dynamic responses of each phase in the transport and phase interactions that impact the transport phenomena. Aimed to serve as an educational, learning-oriented text that introduces multiphase flows to engineering students, advanced researchers, and other readers, this unified textbook methodically encompasses a broad range of the important elements of knowledge in the multiphase flow field, along with sufficient theoretical and applied details in a manner suitable to both introductory and advanced level learning in an instructional setting.The book has twelve chapters, with six on a systematic introduction of multidisciplinary fundamentals critical to understanding multiphase flows, two on the numerical methods and experimental techniques of multiphase flows, and four on selected subjects of multiphase flow systems. Aided with ample examples and problems in each chapter (with available solution manual), this book can be used for advanced undergraduate and graduate courses in many engineering disciplines including mechanical, power, chemical, pharmaceutical, environmental, and process system engineering.