Aerodynamics of V/STOL Flight

This book was developed from a set of notes collected over the years which began in connection with a course on helicopter aerodynamics. As the field of V/STOL aerodynamics developed, this material was integrated into the course. As a result this book is more than simply a book on heli­copters. It begins with a presentation of some general theoretical and applied aerodynamics emphasizing in particular the use of the momentum theorem. This is followed by a development of finite wing theory. The treatment here is somewhat different from that to be found in most other aerodynamic texts in that the deflection of the trailing vortex system is considered which leads to a limiting wing lift coefficient.

Next, propeller and helicopter rotor theory is covered for both the static and forward flight cases. Consideration is given to both momentum and vortex theory in the design and analysis of propellers and rotors.

Other subjects which are treated range from the application of boundary layer control for delaying both separation and transition to the thrust augmentation of jets by the entrainment of a secondary flow.

The book is a mixture of both applied and analytical considerations although its primary theme is of a practical flavor. Most of the material is basic or general with the results of design studies and comparison of one V/STOL configuration with another being purposely avoided. The book is intended to be used as both a reference and a text. The notes on which the work is based have been used for both senior-level undergraduate and graduate courses.

In closing I wish to express my appreciation to those who contributed directly or indirectly to the completion of this volume. To my wife, Emily, goes my thanks for her help in the preparation of the manuscript, while my daughter, Cindy, deserves some recognition for leaving her Dad alone during the trials and tribulations of writing. I would also like to thank

Professor David Hazen of Princeton University for his review and con­structive criticism of the manuscript, and Mr. Gerald Hall, a colleague at Penn State, for his many helpful suggestions.

University Park, Pennsylvania January, 1967