SOLID MOTOR PROPELLANT

SOLID MOTOR PROPELLANT

Post by al.jack.. » Mon, 02 May 1994 09:13:50



 > The new BATF regulations could make KClO4 propellants less
 > practical.
 > They deliver only 70-75% of the Isp of NH4ClO4 propellants, so high
 > range G's are problematic. Also, they burn much hotter than AP
 > composites, so their use in reloadables is also problematic. With
 > low
 > Isp and without the segmentation dodge (unless the technology is
 > better
 > than I judge it to be) the G-I range is going to be tough to fill.
 > Below
 > that is no problem, and above that, all motors will be
 > over-regulated.

Hmmm they burn hotter but the chamber temp is still low?
Isnt the charactestic exhaust velocity proportional to the
square root of the temp?

 
 
 

SOLID MOTOR PROPELLANT

Post by Xiaoyi Eve Zhan » Wed, 04 May 1994 11:33:51


Hi, Al.

The molecular weight of the exhaust is higher for KClO4 propellants. The
temperature is proportional to the translational energy per molecule,
but if the average molecular weight of each molecule is greater, then
the translational energy per gram is lower. Exhaust velocity is
proportional to the square root of translational energy per gram, which
is also proportional to the square root of (temp/molecular weight). Add
to this the extra energy consumed in the extra degrees of freedom in
KClO4 propellants, and you get even less performance. For a Maraschino
cherry, KP propellants typically have high pressure exponents. Slightly
fouled nozzles could result in explosions; slightly erroded ones could
result in drastically lowered thrust.

Hmmm... Maybe losing these things won't be so bad after all :-)

Best Regareds,
-LArry Curcio