Aerodynamic study of a small hypersonic plane

Access to Space is still in its early stages of commercialization. Most of the attention is currently focused on sub-orbital flights, which allow Space tourists to experiment microgravity conditions for a few minutes and to see a large area of the Earth, along with its curvature, from the stratosphere. Secondary markets directly linked to the commercial sub-orbital flights may include microgravity research, remote sensing, high altitude Aerospace technological testing and astronauts training, while a longer term perspective can also foresee point-to-point hypersonic transportation. In recent years some private enterprises have started to develop reusable airplane-like vehicles to perform sub-orbital missions. The design of such vehicles is based on the integration of the systems developed for aeronautical purposes and the technological solutions required for the flight into the stratosphere at super-hypersonic speed. In this scenario University of Naples "Federico II", with the support of other universities and small and medium enterprises, is investigating a new concept for a small passenger hypersonic airplane of six seats, for long-duration sub-orbital Space tourism missions and point-to-point medium range hypersonic transportation. Such aircraft will operate on short-medium length runways of existing even small airports, since it is intended to take-off and land horizontally with relatively small speed and landing loads. The vehicle conceptual design is defined by the complex interplay of aerodynamics, atmospheric heating, materials, structures, propulsion, fuel selection and flight mechanics/dynamics. The flight envelope covers subsonic, transonic, supersonic and hypersonic flight regimes, being hypersonic the most challenging one, constrained on the lower boundary by heating and material limits, and on the upper boundary by aerodynamic lift and propulsion performance. Main objective of the present thesis is to provide some contributions to the studies of this vehicle, through a synergistic integration between disciplines such as aerothermodynamics, propulsion and flight mechanics. In particular this work has been focused on the aerodynamic analysis, which is essential for the evaluation of the effects of the aerodynamic heating and for flight mechanics studies. In this context a validation methodology of an engineering tool has been carried out, aimed at the achievement of the aerodynamic database covering all flight regimes and the prevision of the surface thermal loads which occur in the hypersonic phase, the most severe condition in terms of aerodynamic heating. The evaluation of the effects of the aerodynamic heating has allowed a preliminary identification of proper materials able to sustain the hypersonic phase. These analyzes are related to a preliminary reference configuration. Flight mechanic studies have allowed to refine the vehicle, although more detailed studies on the upgraded configuration are foreseen as future development. The aerodynamic database of the upgraded configuration has been implemented in a flight simulator, along with propulsion and inertia data and trim performances have been evaluated.