Applying supersonic counter-?owing cold gas jets of a certain mass flow rate and pressure at the nose of a supersonic vehicle can reduce drag, aerodynamic heating and possibly reshape sonic boom signatures. Wind tunnel and computational fluid dynamics results (shown here) clearly indicate modification of the supersonic shocks by a counter flowing cold gas (air) jet at Mach number 3.48 in a blunt body.
This technology will enable new flight vehicle concepts and applications of supersonic and hypersonic flight. While previous work done with high energy counter-flowing plasma jets has historically shown limited practicality or effectiveness, we believe our low energy cold gas jet concept leverages a previously unknown aspect of natural aerodynamics, momentum transfer and shock dispersion, as demonstrated in the wind tunnel testing. These effects have been shown to reduce aerodynamic heating of the body and it is possible that drag is reduced as well.
Our patent-pending cold gas delivery system and closed loop control technology may also be used to counteract forcing functions caused by wind gust loads and vehicle-generated oscillations.
Our concept does not alter the outer mold line of the vehicle and it is activated and modulated in flight only as needed. For air-breathing vehicles the jets could be continuously fed by external atmosphere, collected at engine inlets for example.
This work has the potential to enable radical improvements in supersonic aircraft performance and efficiency, lower thermal protection system mass due to moderated aero-thermal environments and reduced sonic boom signatures at the ground. It may also provide a quieter ride for passengers by providing a means to actively counteract aero-structural dynamic flutter and noise in flight.
This concept will enable hypersonic, suborbital passenger transports that connect the cities of Earth, allowing passengers to travel great distances in very short times, for instance, from New York to Sydney, Australia in less than three hours.
The Computational Fluid Dynamics (CFD) data images above were provided by B.S Venkatachari, Y. Ito, Gary Cheng, and C-L Chang, (“Numerical Investigation of the Interaction of Counterflowing Jets and Supersonic Capsule Flows,” AIAA Paper 2011-4030)."