Potassium Nitrate/Calcium Ammonium Nitrate Isomaltitol Eutectic Propellant (KCaIM)
The burn rate of a Potassium/CalciumAmmonium Nitrate eutectic propellant using sorbitol as a fuel is very slow (see KCaSO). Sugar propellants based on Isomaltitol sugar fuel burn much faster. A propellant using the above eutectic oxidizer mixture and isomaltitol fuel in combination with RIO burn rate accelerator (1%) was evaluated. The test stand results of this propellant are listed below. As can be seen, this propellant does indeed burn at a much faster rate, finishing in a little over 4 seconds rather than a long 10 seconds when sorbitol is used. The chamber pressure reached a maximum of 760 psi at a whopping initial Kn of 600. The ISP of this propellant is very respectable between 125 to 130 sec. CalciumAmmonium Nitrate contains close to 20% water as a hydrate when purchased. Engine testing shows that motor performance does not diminish a great deal if this water is not removed before grain casting. Leaving the water in the formulation greatly increases its pourability. Motors made from Maltitol and Lactitol, two other fast burning sugar alcohol disaccarides did not perform as well as with Isomaltitol sugar.
Note: An attempt to use Sucrose as the sugar fuel with this oxidizer mixture resulted in a black, tarry mixture. It appears that sucrose and other "reducing" sugars such as dextrose and fructose are incompatible with the presence of ammonium nitrate. It is suggested that if the potassium/calcium nitrate eutectic is used with reducing sugars that only the non-ammonium nitrate containing calcium nitrate be used.
The burn rate of a Potassium/CalciumAmmonium Nitrate eutectic propellant using sorbitol as a fuel is very slow (see KCaSO). Sugar propellants based on Isomaltitol sugar fuel burn much faster. A propellant using the above eutectic oxidizer mixture and isomaltitol fuel in combination with RIO burn rate accelerator (1%) was evaluated. The test stand results of this propellant are listed below. As can be seen, this propellant does indeed burn at a much faster rate, finishing in a little over 4 seconds rather than a long 10 seconds when sorbitol is used. The chamber pressure reached a maximum of 760 psi at a whopping initial Kn of 600. The ISP of this propellant is very respectable between 125 to 130 sec. CalciumAmmonium Nitrate contains close to 20% water as a hydrate when purchased. Engine testing shows that motor performance does not diminish a great deal if this water is not removed before grain casting. Leaving the water in the formulation greatly increases its pourability. Motors made from Maltitol and Lactitol, two other fast burning sugar alcohol disaccarides did not perform as well as with Isomaltitol sugar.
Note: An attempt to use Sucrose as the sugar fuel with this oxidizer mixture resulted in a black, tarry mixture. It appears that sucrose and other "reducing" sugars such as dextrose and fructose are incompatible with the presence of ammonium nitrate. It is suggested that if the potassium/calcium nitrate eutectic is used with reducing sugars that only the non-ammonium nitrate containing calcium nitrate be used.
338KCaIM + RIO
Thrust Duration = 4.26 sec
Throat Area = 0.0271 in2
Propellant Mass = 183.3g = 0.404 lb
Max Thrust ~ 21 lbs
Max. Chamber Pressure ~ 275 psi
Ave. Thrust = 11.05 lbs = 49.2 N
Total Impulse = 209.5 N Sec = 47.1 lb sec
ISP = 117 sec
Motor Class = H49
Initial Kn = 500
Thrust Duration = 4.26 sec
Throat Area = 0.0271 in2
Propellant Mass = 183.3g = 0.404 lb
Max Thrust ~ 21 lbs
Max. Chamber Pressure ~ 275 psi
Ave. Thrust = 11.05 lbs = 49.2 N
Total Impulse = 209.5 N Sec = 47.1 lb sec
ISP = 117 sec
Motor Class = H49
Initial Kn = 500
338 KCaIM + RIO
Thrust Duration = 4.15 sec
Throat Area = 0.0225 in2
Propellant Mass = 182.6 g = 0.402 lb
Max. Thrust = 24 lbs
~Max. Chamber Pressure = 760 psi
Ave. Thrust = 12.7 lbs = 56.5 N
Total Impulse = 235 N sec = 52.7 lb sec
ISP = 131 sec
Motor Class = H57
Init. Kn = 600
Thrust Duration = 4.15 sec
Throat Area = 0.0225 in2
Propellant Mass = 182.6 g = 0.402 lb
Max. Thrust = 24 lbs
~Max. Chamber Pressure = 760 psi
Ave. Thrust = 12.7 lbs = 56.5 N
Total Impulse = 235 N sec = 52.7 lb sec
ISP = 131 sec
Motor Class = H57
Init. Kn = 600
254 KCaNH4IM + RIO
Thrust Duration = 7.26 sec
Propellant Mass = 453.1 g = 1.00 lb
Throat Area = 0.03267 in2
Max. Thrust = 26 lbs
Max. Chamber Pressure = 570 psi
Ave. Thrust = 17.3 lbs = 77 N
Total Impulse = 559 N sec = 126 lb sec
ISP = 126 sec
Initial Kn = 600
Motor class = I77
Medusa Nozzle
338 KCaNHIM YIO Water not removed
Propellant Mass = 171.8 g = 0.378 lb
Nozzle Throat area = 0.01938 in2
Burn Time = 4.3 sec
Max. Thrust = 16 lbs
~Max. Chamber Pressure = 590 psi
Ave. Thrust = 9.8 lbs = 43.6 N
Total Impulse = 188 N sec = 42.1 lb sec
ISP = 112 sec
Motor Class = H42
Kn > 600
Propellant Mass = 171.8 g = 0.378 lb
Nozzle Throat area = 0.01938 in2
Burn Time = 4.3 sec
Max. Thrust = 16 lbs
~Max. Chamber Pressure = 590 psi
Ave. Thrust = 9.8 lbs = 43.6 N
Total Impulse = 188 N sec = 42.1 lb sec
ISP = 112 sec
Motor Class = H42
Kn > 600
