Preface

Hypersonic vehicles represent the next frontier of transportation systems. This is true both for travels to and from space and for fast passenger transportation. Indeed, after the retirement of NASA's Space Shuttle, scientific applications in Low Earth Orbit (LEO) strongly highlight the need for flexible, affordable, comfortable and safe routine access to space.

In the last decade, the attention to hypersonic travel for civilian application has dramatically increased. Many start-up and aerospace companies are focusing attention on the potential benefit of hypersonic aircrafts able to fly from point to point all over Earth in less than 2–3 hours for both passenger and goods transportation.

As a result, the aerospace field, despite past important achievements, still focuses greatly on high-speed vehicle design.

The quest to fly higher and faster, however, is still a challenging goal for the field of aerospace engineering, especially for human-rated missions. In fact, highspeed hypersonic vehicles demand several design issues to be addressed, such as aircraft aerodynamics and aerothermodynamics, aeroshape design optimization, aerodynamic heating, boundary layer transition, propulsion system integration, low-speed flying qualities, and so on.

Among others, aeroshape optimization perhaps represents the fundamental aspect in designing such vehicles. Indeed, high-speed vehicle design is an extremely challenging process involving several disciplines, including aerodynamics, aerothermodynamics, control, avionics navigation systems, propulsion, and structure. As well known, these disciplines are strongly coupled with one another and generally influence each other because they involve antagonistic objectives. Therefore, it is expected that synergistic interactions between vehicle sub-systems and functions can produce an optimized multidisciplinary vehicle design with significant performance and economic improvements.

In this framework, this book contains contributions focusing on hypervelocity aircraft design. For instance, the extreme loading environment of high-speed flows demands advanced aeroshape designs that are able to sustain large heat transfer and mechanical loading conditions while providing aerodynamic force and moments to sustain both re-entry and hypersonic flights. Therefore this book covers such topics as hypersonic aircraft aerodynamic and aerothermodynamic design, aeroshape design optimization, computational fluid dynamics, and scramjet propulsion. The book also discusses high-speed flow issues and the challenges to achieving the

dream of affordable hypersonic travel. It is hoped that the information contained herein will allow for the development of safe and efficient hypersonic vehicles.

**Giuseppe Pezzella and Antonio Viviani**

Engineering Department, University of Campania "L. Vanvitelli", Aversa (CE), Italy

**1**

Section 1

Hypersonic Vehicles:

Past, Present and Future

Section 1
