K Na Mannitol Propellant
aka       KNaMan
A Eutectic oxidizer propellant that I have come to enjoy flying is based on the use of Mannitol as the sugar fuel.  The use of Mannitol with the mixed oxidizer overcomes the extreme propellant contraction that occurs when only KNO3 is used as the oxidizer with mannitol fuel.  The "KNaMan" propellant has the same extremely low water adsorption as the KNO3 only based propellant as well.  Burn times are moderate making this propellant an easy one to use, although it must be worked with at higher temperatures.  Care in handling is cautioned, making sure splashes and burns are not encountered.  This propellant is prepared by mixing 35g KNO3, 30g NaNO3, and 35g mannitol together and heating the mixture to ~180C.  This melting is best accomplished using an electric skillet.  A skillet temperature around 350 - 375F should be chosen.  All of the ingredients are mixed and added to the skillet.  The sugar will melt first and then the oxidizers will slowly melt/dissolve.  Once all the solids have disappeared the liquid propellant can be poured into casting tubes directly from the skillet. The liquid propellant crystallizes very quickly once it leaves the center of the skillet so some pace needs to be used in pouring propellant grains.  An initial Kn of 300 works best with this propellant.
238 KNaMan
Thrust Duration = 3.22 sec
Nozzle Throat Area = 0.03016 in2
Propellant Mass = 116.7 g = 0.257 lb
Max. Thrust = 14 lbs
Max. Chamber Pressure = 330 psi
Ave. Thrust = 8.78 lbs = 39 N
Specific Impulse = 28.3 N Sec = 126 N sec
ISP = 110 sec
Motor Class = G39
Initial Kn = 300
338 KNaMan
Thrust Duration = 3.40 sec
Nozzle Throat Area = 0.03315 in2
Propellant Mass = 173.9 g = 0.383 lb
Max. Thrust = 24 lbs
Max. Chamber Pressure = 520 psi
Ave. Thrust = 12.75 lbs = 56.7 N
Total Impulse = 193 N sec = 43.4 lb sec
ISP = 113
Motor Class = H57
Initial Kn = 400
Mixed Oxidizers