Preface

In the aerospace field, hypersonic flight plays a fundamental role.

Some sixty years after the experimental flights of the North American X-15 hypersonic rocket-powered aircraft, sustained hypervelocity travel is still the next frontier in high-speed transportation.

Today, there is much excitement and interest regarding hypersonic vehicles. In fact, many aerospace agencies, large industries, and several start-ups are involved in many design activities and experimental campaigns both in wind tunnels and in-flight with full-scale experimental flying test beds and prototypes. Therefore, the dream of flying higher and faster with a hypersonic airplane, thus making hypersonic travel almost as easy and convenient as airliner travel, is increasingly becoming a reality.

Achieving this goal will radically revolutionize the future of civil transportation.

However, flying at hypersonic speeds requires advanced vehicle design and testing and the creation of critical technologies to overcome the many technical challenges associated with hypersonic flight.

To address these challenges, a lot of research efforts involve international scientific and industrial communities to ensure that high-speed flight tests are successful. Some of these efforts are summarized in this book, in terms of numerical and ground-based experimental activities.

Within this framework, this book is designed to support industries, research centers, and space agencies in their design and development of next-generation high-speed transportation. It is divided into three sections: "Introduction," "Experimental Investigations" and "Vehicle Design Analysis." Each section contains valuable contributions that focus on various design issues related to hypersonic aircraft. It is hoped that the information contained herein will enable the development of safe and efficient hypervelocity vehicles.

This book is recommended for both students and research engineers involved in all design phases typical of hypersonic vehicle design.

> **Giuseppe Pezzella and Antonio Viviani** Engineering Department, University of Campania "L. Vanvitelli", Aversa, Italy

Section 1 Introduction
