The engineers and scientists last week presented the findings of their research into “low-boom” supersonic flight in Atlanta at Aviation 2014, an event hosted by the American Institute of Aeronautics and Astronautics.
The researchers have been investigating how to lower the noise impact of sonic booms, which is the reason for the FAA ban on supersonic travel over land.
At the first sonic boom prediction workshop, scientists from Japan, the US and France, examined varying aircraft configurations – cylindrical bodies with and without wings – as well as complex full aircraft designs for their sonic boom potential.
Mike Park, a fluid mechanics engineer at Langley, said: “We found for simple configurations we can analyse and predict sonic booms extremely well. For complex configurations we still have some work to do.”
Wind tunnels are also being used to help predict which designs might have quieter booms, with recent tests at NASA research centres in California and Cleveland finding that designs similar to those used in the past – “a needle-like nose, sleek fuselage and a delta wing or highly-swept wings” – result in much lower booms.
“Lessening sonic booms – shock waves caused by an aircraft flying faster than the speed of sound – is the most significant hurdle to reintroducing commercial supersonic flight,” said Peter Coen, head of the high speed project in NASA’s aeronautics research mission directorate.
However, Coen acknowledged that this isn’t the only barrier to a world of supersonic commercial aviation. High altitude emissions, fuel efficiency and community noise around airports, are also significant challenges, he acknowledged.
To this should also be added maintenance costs and a tough market. Expensive maintenance and a lack of demand for tickets are key reasons why Concorde is no longer flying.
A new supersonic passenger jet would provide challenges in MRO which would, undoubtedly, be overcome if there was a big enough market for services. However, the biggest challenge in our modern world of low-cost carriers, unstable fuel prices and squeezed margins, will be whether passengers will want to pay for the pleasure of travelling faster than the speed of sound.
The commercial aviation sector is almost unrecognisable from the one that designed and built Concorde in the 1960s. And while the practicalities of quietening sonic booms are “within reach”, it seems that there are other considerations that might well scupper commercial supersonic travel