For now I would prefer scramjet powered hypersonic missiles rather than gliders.
A Scramjet engine powered hypersonic missile, if flying through dense atmospheric layers will be subjected to very acute temperature increases at boundary layers due to air molecules ahead of the hypersonic structure are decelerated across the bow shock, and the converted kinetic energy creates very high temperatures at the leading edges.
At lower altitudes, the ambient pressure and density are so much higher that the stagnation and viscous temperature effects are exacerbated.
Typically a re entry vehicle travelling at 6 Mach may generate tip temperatures of 1300Kelvin at 100Km altitude, could have tip temperatures of 2300Kelvln at 10Km altitude.
Scramjet powered missiles, to be effective, have to travel at comparatively lower altitudes and hence denser atmospheric layers. They have to achieve 5 to 10 Mach speeds at these altitudes. This brings with it, a lot of technical obstacles and difficulties to overcome. Materials Science plays a big part in solving these problems. Tungsten, reinforced carbon and carbon composites are used at the affected tips and edges to withstand these high temperatures.
Theoretically a scramjet engine can operate at a maximum altitude of 75km. But lower the flight altitude, lower the chances of detection. However lower the altitude, higher the temperature created limitations.
Most importantly, as Scramjet powered missiles have to travel through comparatively thick layers of atmosphere, they are limited by the fuel they carry. Hence much shorter ranges (less then 10th of) than a HGV.
Below is an interesting article on Zircon, the Russian so called hypersonic scramjet powered cruise missile, and the technical challenges it faces.
Russian moves to operationalise the Zircon hypersonic missile represent an important development, but the significance – especially in terms of the current conflict – should not be overstated.
www.rusi.org
KUZGUN-SS Munition Firing Test
Bull’s Eye
Sinop
gids.com.pk
www.twz.com
