The object of this book is to provide a fairly broad treatment of the fluid mechanics of turbomachinery. Emphasis is placed on the more utilitarian equipment, such as axial flow turbomachines, and centrifugal turbomachines that will be encountered by most mechanical engineers as they pursue careers in industry that specifically deals with water. While writing the book, I have always kept in mind the examination requirements for third classes in mechanical engineering department and the requirements of other engineering students, who are always interested in having up-to-date information, by incorporating the research work countries on allied topics; available from numerous specialized technical books, papers and periodicals. Thus, the book will provide the students with necessary insight into the subject, and prepare them adequately for their examinations. To make the book more useful at all levels, it has been written in an easy style and such a simple manner, that a student can grasp the subject even independently. Care has been taken to make the whole book as self explanatory as possible.