Supersonic jets on the horizon The dream of building extremely fast aeroplanes is within reach as technology advances to the required levels. Methodologies to develop the required propulsion systems must be established if the dream is to become reality. Industrial Technologies © Shutterstock Propulsion systems and engines in commercial aeroplanes have been based on the same technology for decades. Increasing globalisation and air travel, however, are putting pressure on the industry to exploit the latest research on creating superfast aeroplanes. The EU-funded project 'Long-term advanced propulsion concepts and technologies' (Lapcat) investigated how to jumpstart research on propulsion concepts for hypersonic flight. It looked at key propulsion technologies required to reduce long flights considerably and have them operating at very high speeds ranging from mach four to mach eight. Traditional jet engines are not suitable for such a feat and must be replaced by advanced air-breathing engines. In this light, Lapcat looked at propulsion, structure, cooling and integration of systems into the airframe, defining interfaces and the interactions between aerodynamics and propulsion. This also involved methodology for estimating performance of the airframe and propulsion (intake, combustor and nozzle) during system design processes. The project has mapped how to validate these new aspects of proposed upcoming propulsion technology using experiments and numerical means. For example, it outlined how difficult Nose-to-Tail (NTT) verifications may be overcome, taking into consideration net thrust, lift, wind-tunnel limitations and hot environments. Such verifications call for advanced 3D technology involving computational fluid dynamics (CFD) techniques for external aerodynamics. In addition, with new flight altitudes and speeds, environmental impact must be considered and sonic boom impact. Ways for shifting from kerosene fuel to hydrogen fuel or liquid methane were also explored. With all these considerations and new methodologies, the project has advanced the cause of supersonic air transport and opened endless possibilities for the way ahead.
